GAS SOLUBILITIES IN IONIC LIQUIDS:

EXPERIMENTAL MEASUREMENTS AND APPLICATIONS

A Dissertation

Submitted to the Graduate School

of the University of Notre Dame

in Partial Fulfillment of the Requirements

for the Degree of

Doctor of Philosophy

by

Jennifer Lynn Anthony, B.S., M.S.

______Joan F. Brennecke, Director

______Edward J. Maginn, Director

Graduate Program in Chemical and Biomolecular Engineering

Notre Dame, Indiana

January 2004

© Copyright by

Jennifer Lynn Anthony

2004

All rights reserved

GAS SOLUBILITIES IN IONIC LIQUIDS:

EXPERIMENTAL MEASUREMENTS AND APPLICATIONS

Abstract

by

Jennifer Lynn Anthony

Solvents play an extremely important role in many industrial processes, acting as

a media for chemical reactions or for extraction of products. Typically, these solvents

are volatile organic compounds or VOCs. As the VOCs volatilize, the risk of human

exposure through inhalation is increased. VOCs have also been found to increase

ozone depletion and smog formation. Therefore, it is important to find other solvents

that still meet the needs of industry while limiting the environmental and health risks.

Room temperature ionic liquids (ILs) have recently been getting attention as potential environmentally benign or “green” solvents. Ionic liquids, organic salts that are liquids in their pure states at ambient conditions, have many properties that are similar to conventional organic solvents. But, many ILs also have the unique characteristic in that they exhibit a vanishingly low vapor pressure. This negligible volatility eliminates many of the concerns associated with traditional organic solvents by decreasing the risk of worker exposure and the loss of solvent to the atmosphere. Jennifer Lynn Anthony

The main objective of this research is to determine thermodynamic/phase

behavior properties by studying the phase behavior of the ionic liquids with various gases and liquids to further develop the relationships between these properties and the molecular structure of these ionic liquids. Knowledge of these properties is necessary prior to design and development of industrially relevant processes using ILs.

This work explores the solubility and associated thermodynamic properties, such as Henry’s law constants, and enthalpies and entropies of absorption, of a variety of gases in various ionic liquids, mainly those with 1-n-butyl-3-methylimidazolium as the cation and [PF6], [BF4], and [Tf2N] as the anions. The gases considered range from simple nonpolar compounds to more complex polar gases capable of hydrogen

bonding. Water vapor, carbon dioxide, and nitrous oxide show the strongest

interactions with the ionic liquids, whereas gases like N2, O2 and Ar are only

sparingly soluble. This work also shows ionic liquids have potential for use as a gas

separation medium.

DEDICATION

To my family, for your continual love and support.

ii

TABLE OF CONTENTS

FIGURES...... vii

TABLES ...... xi

ACKNOWLEDGMENTS ...... xv

CHAPTER 1: INTRODUCTION AND BACKGROUND ...... 1

1.1 Introduction...... 1 1.2 Ionic Liquids ...... 1 1.3 Solvent for Reactions...... 3 1.4 Physical Properties...... 3 1.4.1 Pure component properties ...... 3 1.4.2 Mixture properties...... 4 1.4.2.1 Liquid solubilities ...... 5 1.4.2.2 Gas solubilities...... 5 1.4.2.3 Molecular interactions ...... 6 1.4.2.4 Molecular simulations...... 7 1.5 Additional Uses and Applications ...... 7 1.5.1 Liquid-liquid extraction ...... 8 1.5.2 Extractive distillation...... 9 1.5.3 Supercritical extraction ...... 9 1.5.4 Gas separations ...... 9 1.6 Objective of Thesis ...... 10 1.7 Outline of Chapters...... 10

CHAPTER 2: GENERAL METHODOLOGY AND THEORY...... 13

2.1 Methods for Measuring Gas Solubilities ...... 13 2.1.1 Volumetric and pressure drop methods ...... 14 2.1.2 Gas chromatography ...... 15 2.1.3 Gravimetric method ...... 16 2.1.3.1 Buoyancy correction ...... 16 2.1.3.2 Advantages of gravimetric method...... 19 2.1.4 Other techniques ...... 20 2.2 Thermodynamic Properties...... 20 2.2.1 Derivation for Henry’s constants...... 20 2.2.2 Derivation for enthalpy and entropy of absorption...... 22

iii CHAPTER 3: EXPERIMENTAL DETAILS...... 24

3.1 Materials ...... 24 3.1.1 Ionic liquids ...... 24 3.1.2 Gases...... 31 3.2 Gravimetric Microbalance ...... 32 3.2.1 Experimental procedure...... 33 3.2.2 Accounting for buoyancy...... 37 3.2.3 Ensuring equilibrium ...... 41 3.2.4 Error analysis ...... 42 3.3 Static High-Pressure Apparatus ...... 44 3.3.1 Apparatus details...... 44 3.3.2 Dry versus water-saturated experiments...... 48 3.4 H2O / IL Liquid-Liquid Equilibrium Measurements ...... 48 3.4.1 LLE setup...... 48 3.4.2 Analysis of liquid phases ...... 49 3.5 Activated Carbon Measurements...... 50 3.6 Gas Separations Measurements ...... 51 3.6.1 Analysis of gas composition ...... 51 3.6.2 Supported ionic liquid membranes ...... 52 3.6.2.1 Membrane apparatus...... 52 3.6.2.2 Membrane preparation...... 54 3.6.2.3 Operating procedure...... 56 3.6.3 Absorber...... 57

CHAPTER 4: RESULTS - GAS SOLUBILITIES...... 58

4.1 Solubility of Carbon Dioxide...... 58 4.1.1 Effects of anion with [bmim] cation ...... 59 4.1.1.1 [bmim][PF6] ...... 59 4.1.1.2 [bmim][BF4]...... 60 4.1.1.3 [bmim][Tf2N]...... 61 4.1.1.4 Comparison between ionic liquids...... 62 4.1.1.5 Henry’s constants...... 64 4.1.1.6 Enthalpies and entropies of absorption...... 66 4.1.2 Effect of methyl group versus hydrogen on cation...... 67 4.1.2.1 Solubility isotherms ...... 68 4.1.2.2 Henry’s constants...... 71 4.1.2.3 Enthalpies and entropies of absorption...... 72 4.1.3 Effect of cation with [Tf2N] anion...... 73 4.1.3.1 Solubility isotherms ...... 74 4.1.3.2 Henry’s constants and enthalpies and entropies of absorption...... 76 4.2 Other Gases Solubilities...... 77 4.2.1 [bmim][PF6] ...... 78 4.2.1.1 Solubility isotherms ...... 78

iv 4.2.1.2 Henry’s constants...... 80 4.2.2 Other gases in [bmim][BF4]...... 82 4.2.2.1 Solubility isotherms ...... 82 4.2.2.2 Henry’s constants and infinite dilution activity coefficients...... 83 4.2.3 Other gases in [bmim][Tf2N]...... 85 4.2.3.1 Solubility isotherms ...... 85 4.2.3.2 Henry’s constants...... 86 4.2.4 Comparison between ionic liquids...... 87 4.2.5 Molecular interactions ...... 90 4.2.6 Comparison to other solvents...... 93 4.2.7 Enthalpies and entropies of absorption...... 95 4.2.8 Other systems...... 98 4.3 Summary...... 99

CHAPTER 5 RESULTS: IONIC LIQUIDS AND WATER...... 101

5.1 Water Vapor in Various Ionic Liquids...... 101 5.1.1 Solubility isotherms ...... 102 5.1.2 Henry’s constants and infinite-dilution activity coefficients...... 106 5.1.3 Enthalpy and entropy of absorption...... 109 5.2 Ionic Liquid and Water Liquid-Liquid Equilibrium ...... 110 5.2.1 Ambient conditions...... 110 5.2.2 Comparison to other solvents...... 113 5.2.3 Elevated temperatures...... 114 5.3 Practical Issues Due to Cross-Contamination Between Phases...... 115 5.3.1 Removing water from ionic liquid phase...... 115 5.3.2 Effect of water on gas solubilities...... 116 5.3.3 Removing ionic liquid from the aqueous phase...... 118 5.4 Summary...... 120

CHAPTER 6: IONIC LIQUIDS AS MEDIA FOR GAS SEPARATIONS...... 121

6.1 Introduction...... 121 6.2 Gas Separations Theory ...... 123 6.2.1 Separations using membranes...... 123 6.2.2 Separations using absorber ...... 124 6.3 Ideal Separation Factors...... 124 6.4 Supported Ionic Liquid Membranes ...... 129 6.5 Absorber...... 132 6.6 Energy Comparison to Conventional Techniques ...... 134 6.6.1 Current design using monoethanolamine...... 134 6.6.2 MEA absorption energy calculations...... 135 6.7 Alternative Ionic Liquid Options...... 139 6.7.1 Ideal carrying capacities ...... 139 6.7.2 Ionic liquid design...... 140

v 6.8 Summary...... 141

CHAPTER 7: CONCLUSIONS AND RECOMMENDATIONS...... 142

7.1 Conclusions...... 142 7.2 Recommendations...... 144

APPENDIX A: CALIBRATION CURVES FOR ICP-OES MEASUREMENTS...... 147

APPENDIX B: ERROR ANALYSIS FOR HENRY’S CONSTANTS...... 149

APPENDIX C: CALIBRATION CURVES FOR UV-VISIBLE SPECTROSCOPY MEASUREMENTS ...... 152

APPENDIX D: RAW DATA FOR GAS SOLUBILITY MEASUREMENTS USING THE GRAVIMETRIC MICROBALANCE...... 155

APPENDIX E: FLOWING VERSUS STATIC MODES ON THE GRAVIMETRIC MICROBALANCE...... 278

APPENDIX F: RAW DATA FOR HIGH PRESSURE CARBON DIOXIDE SOLUBILITY MEASUREMENTS...... 279

REFERENCES ...... 281

vi

FIGURES

Figure 1.1 Schematic of example classes of ionic liquids...... 2

Figure 2.1 Schematic of a balance used in the gravimetric techniques with symmetric sample (I) and counterweight (II) sides ...... 17

Figure 3.1 Gravimetric microbalance...... 32

Figure 3.2 Schematic of the gravimetric microbalance...... 33

Figure 3.3: Quartz sample bucket containing an ionic liquid sample for the microbalance apparatus...... 34

Figure 3.4 Mass change in [bmim][PF6] as a function of time due to water absorption while increasing the pressure from 20 mbar to 25 mbar....36

Figure 3.5 Absorption and desorption isotherms for CO2 solubility in o o [bmim][Tf2N] at 10 C and 50 C ...... 37

Figure 3.6 Buoyancy scan using helium for quartz sample bucket...... 38

Figure 3.7 Schematic of static high pressure apparatus ...... 45

Figure 3.8 Schematic of the supported liquid membrane apparatus ...... 53

o o o Figure 4.1 CO2 in [bmim][PF6] at 10 C, 25 C, and 50 C ...... 60

o o o Figure 4.2 CO2 in [bmim][BF4] at 10 C, 25 C, and 50 C...... 61

o o o Figure 4.3 CO2 in [bmim][Tf2N] at 10 C, 25 C, and 50 C ...... 62

vii

o Figure 4.4 CO2 in [bmim][PF6], [bmim][BF4], and [bmim][Tf2N] at 25 C...... 63

Figure 4.5 Comparison of CO2 in [bmim][PF6] at low and high pressures...... 64

Figure 4.6 Structure of imidazolium ring with hydrogen or methyl group at the 2-carbon position...... 67

Figure 4.7 Solubility of CO2 in [emim][Tf2N], [emmim][Tf2N], [bmim][PF6], o [bmmim][PF6], [bmim][BF4], and [bmmim][BF4] at 10 C ...... 69

Figure 4.8 Solubility of CO2 in [emim][Tf2N], [emmim][Tf2N], [bmim][PF6], o [bmmim][PF6], [bmim][BF4], and [bmmim][BF4] at 25 C ...... 69

Figure 4.9 Solubility of CO2 in [emim][Tf2N], [emmim][Tf2N], [bmim][PF6], o [bmmim][PF6], [bmim][BF4], and [bmmim][BF4] at 50 C ...... 70

o Figure 4.10 CO2 solubility in various ionic liquids at 25 C...... 75

o Figure 4.11 CO2 solubility in various ionic liquids at 50 C...... 75

o o o Figure 4.12 C2H4 solubility in [bmim][PF6] at 10 C, 25 C, and 50 C...... 79

o Figure 4.13 Solubility in various gases in [bmim][PF6] at 25 C...... 80

o o o Figure 4.14 Solubility of C6H6 in [bmim][BF4] at 10 C, 25 C, and 50 C along the liquid-liquid equilibrium value at 25 ...... 83

o Figure 4.15 Solubility of a series of gases in [bmim][Tf2N] at 25 C...... 86

Figure 4.16 Solubility of CH4 in [bmim][PF6], [bmim][BF4], and [bmim][Tf2N]...... 87

Figure 4.17 Comparison of Henry’s constants in [bmim][PF6], [bmim][BF4],

and [bmim][Tf2N] ...... 88

viii

Figure 4.18 Solubility dependence on polarizability for gases in [bmim][PF6]

and [bmim][Tf2N] ...... 92

Figure 5.1 Solubility of water vapor in [bmim][PF6]...... 102

Figure 5.2 Solubility of water vapor in [C8mim][PF6]...... 103

Figure 5.3 Solubility of water vapor in [C8mim][BF4] ...... 103

Figure 5.4 Solubility of CO2 in [bmim][Tf2N] at low and high pressures with dry and water saturated samples ...... 117

Figure 6.1 Separation factor for CO2 relative to CH4 using [bmim][PF6] coated membranes over time ...... 130

Figure 6.2 Breakthrough curves for the removal of CO2 from N2 using [bmim][PF6] as the absorbent ...... 133

Figure 6.3 Breakthrough curves for the removal of CO2 from CH4 using [bmim][PF6] as the absorbent ...... 134

Figure 6.4 Example of a CO2 absorption system using MEA...... 135

Figure A-1 Calibration for silver in water...... 147

Figure A-2 Calibration for phosphorous in water ...... 148

Figure B-1 Determining the Henry’s constant for CH4 in [bmim][PF6] ...... 149

Figure C-1 Calibration for [bmim][PF6] in water ...... 152

Figure C-2 Calibration for [C8mim][PF6] in water ...... 153

Figure C-3 Calibration for [C8mim][BF4] in water...... 154

Figure E-1 CO2 in [emim][Tf2N] in flowing and static mode ...... 278

ix

TABLES

TABLE 3.1 IONIC LIQUIDS STUDIED WITH THEIR SHORTHAND NOTATION AND STRUCTURE...... 25

TABLE 3.2 VOLUME DIFFERENCES OF THE BALANCE COMPONENTS ...... 39

TABLE 3.3 TEMPERATURE-DEPENDENT DENSITY RELATIONSHIPS FOR THE IONIC LIQUIDS...... 41

TABLE 3.3 PRESSURE DROP CALCULATION TO “BLOW” LIQUIDS OUT OF VARIOUS SIZE PORES...... 55

TABLE 4.1 HENRY’S CONSTANTS AND ENTHALPIES AND ENTROPIES OF ABSORPTION FOR CO2 IN [bmim][PF6], [bmim][BF4], AND [bmim][Tf2N]...... 65

TABLE 4.2 HENRY’S CONSTANTS AND ENTHALPIES AND ENTROPIES OF ABSORPTION FOR CO2 IN [bmim][PF6], [bmmim][PF6], [bmim][BF4], [bmmim][BF4], [emim][Tf2N], AND [emmim][Tf2N] ...... 72

TABLE 4.3 HENRY’S CONSTANTS FOR CO2 IN SEVERAL ILS...... 76

TABLE 4.4 ENTHALPIES AND ENTROPIES OF ABSORPTION FOR CO2 IN [HeBu3N][Tf2N] AND [MeBuPyrr][Tf2N]...... 77

TABLE 4.5 HENRY’S CONSTANTS FOR SEVERAL GASES IN O O O [bmim][PF6] AT 10 C, 25 C, AND 50 C ...... 80

x TABLE 4.6 HENRY’S CONSTANTS FOR SEVERAL GASES IN [bmim][BF4]...... 84

TABLE 4.7 HENRY’S CONSTANTS FOR SEVERAL GASES IN [bmim][Tf2N]...... 86

TABLE 4.8 POLARIZABILITIES (α), DIPOLE MOMENTS (µ), AND QUADRAPOLE MOMENTS (Q) OF THE GASES ...... 91

TABLE 4.9 COMPARISON OF HENRY’S CONSTANTS OF VARIOUS GASES IN [bmim][PF6], [bmim][BF4], AND [bmim][Tf2N] TO THOSE IN CONVENTIONAL SOLVENTS ...... 94

TABLE 4.10 ENTHALPIES OF ABSORPTION FOR VARIOUS GASES IN [bmim][PF6], [bmim][BF4], AND [bmim][Tf2N] AND OTHER SOLVENTS...... 96

TABLE 4.11 ENTROPIES OF ABSORPTION FOR VARIOUS GASES IN [bmim][PF6], [bmim][BF4], AND [bmim][Tf2N] AND OTHER SOLVENTS ...... 97

TABLE 4.12 HENRY’S CONSTANTS AND ENTHALPIES AND ENTROPIES OF ABSORPTION FOR O2 IN SEVERAL ILS...... 99

TABLE 5.1 HENRY’S CONSTANTS, H1, AND INFINITE DILUTION ∞ ACTIVITY COEFFICIENTS, γ , FOR WATER IN [C8mim][BF4], [bmim][PF6], AND [C8mim][PF6]...... 107

TABLE 5.2 LITERATURE VALUES FOR HENRY’S CONSTANTS, H1, AND INFINITE DILUTION ACTIVITY COEFFICIENTS, γ∞, FOR WATER IN VARIOUS ORGANIC SOLVENTS...... 108

TABLE 5.3 ENTHALPY AND ENTROPY CHANGES FOR WATER ABSORBING IN [C8mim][BF4], [bmim][PF6], AND [C8mim][PF6] ...... 109

TABLE 5.4 LITERATURE VALUES FOR THE ENTHALPY AND ENTROPY CHANGES FOR WATERABSORBING IN VARIOUS ORGANIC LIQUIDS...... 110

TABLE 5.5 LIQUID-LIQUID EQUILIBRIUM RESULTS FOR WATER WITH [C8mim][BF4], [bmim][PF6], OR [C8mim][PF6] AT AMBIENT CONDITIONS...... 111

xi

TABLE 5.6 LIQUID-LIQUID EQUILIBRIUM RESULTS FOR WATER AND VARIOUS ORGANICS AT AMBIENT CONDITIONS...... 113

TABLE 5.7 LIQUID-LIQUID EQUILIBRIUM RESULTS FOR WATER AND [bmim][PF6] AT VARIOUS TEMPERATURES...... 114

TABLE 5.8 PERCENT OF [bmim][PF6] REMAINING IN WATER USING ACTIVATED CARBON (+ 3%)...... 119

TABLE 6.1 RATIOS OF HENRY’S CONSTANTS OF VARIOUS GASES IN [bmim][PF6] TO CO2 IN [bmim][PF6]...... 125

TABLE 6.2 ENERGY CALCULATION RESULTS FOR CO2 ABSORPTION AND RECOVERY BY TEMPERATURE-SWING (25 OC TO 100 O C) USING [bmim][PF6] OR 30 WT% MEA SOLUTION (CO2 PARTIAL PRESSURE = 0.1 BAR)...... 137

TABLE 6.3 ENERGY CALCULATION RESULTS FOR CO2 ABSORPTION AND RECOVERY BY TEMPERATURE-SWING (25 OC TO 100 O C) USING [bmim][PF6] OR 30 WT% MEA SOLUTION (CO2 PARTIAL PRESSURE = 1 BAR)...... 138

TABLE 6.4 ENERGY CALCULATION RESULTS FOR CO2 ABSORPTION AND RECOVERY BY TEMPERATURE-SWING (25 OC TO 100 O C) USING [bmim][PF6] OR 30 WT% MEA SOLUTION (CO2 PARTIAL PRESSURE = 2 BAR)...... 138

TABLE 6.5: PARAMETERS FOR THEORETICAL IL THAT WOULD BE COMPETITIVE WITH MEA USING TEMPERATURE-SWING (25 OC TO 100 OC) ABSORPTION AND RECOVERY (GIVES Q = 6.1 MILLION BTU/TON CO2)...... 140

TABLE B-2 SAMPLE ERROR CALCULATIONS FOR CH4 IN [bmim][PF6] AT 50 OC...... 151

TABLE D-1 ARGON IN [bmim][PF6]...... 156

TABLE D-2 BENZENE IN [bmim][BF4] ...... 158

TABLE D-3 CARBON DIOXIDE IN [bmim][BF4] ...... 161

TABLE D-4 CARBON DIOXIDE IN [bmim][PF6]...... 171

xii TABLE D-5 CARBON DIOXIDE IN [bmim][Tf2N] ...... 175

TABLE D-6 CARBON DIOXIDE IN [bmmim][BF4]...... 178

TABLE D-7 CARBON DIOXIDE IN [bmmim][PF6] ...... 181

TABLE D-8 CARBON DIOXIDE IN [emim][Tf2N]...... 186

TABLE D-9 CARBON DIOXIDE IN [emmim][Tf2N] ...... 190

TABLE D-10 CARBON DIOXIDE IN [MeBuPyrr][TF2N]...... 194

TABLE D-11 CARBON DIOXIDE IN [HeBu3N][TF2N] ...... 197

TABLE D-12 CARBON DIOXIDE IN [MeBu3N][TF2N]...... 202

TABLE D-13 CARBON DIOXIDE IN [iBuMeP][TOS]...... 202

TABLE D-14 ETHANE IN [bmim][Tf2N]...... 203

TABLE D-15 ETHANE IN [bmim][PF6]...... 207

TABLE D-16 ETHANE IN [bmim][NO3]...... 210

TABLE D-17 ETHYLENE IN [bmim][TF2N]...... 213

TABLE D-18 ETHYLENE IN [bmim][PF6]...... 216

TABLE D-19 ETHYLENE IN [bmim][NO3]...... 220

TABLE D-20 METHANE IN [bmim][PF6] ...... 223

TABLE D-21 METHANE IN [bmim][BF4]...... 227

TABLE D-22 METHANE IN [bmim][TF2N] ...... 235

TABLE D-23 NITROUS OXIDE IN [bmim][TF2N]...... 243

TABLE D-24 OXYGEN IN [bmim][PF6]...... 249

TABLE D-25 OXYGEN IN [bmim][TF2N]...... 254

TABLE D-26 OXYGEN IN [iBuMeP][TOS] ...... 257

TABLE D-27 OXYGEN IN [HeBu3N][TF2N]...... 258

xiii TABLE D-28 OXYGEN IN [MeBu3N][TF2N]...... 259

TABLE D-29 OXYGEN IN [MeBuPyrr][TF2N] ...... 261

TABLE D-30 WATER IN [bmim][PF6]...... 264

TABLE D-31 WATER IN [C8mim][BF4] ...... 270

TABLE D-32 WATER IN [C8mim][PF6]...... 274

TABLE F-1 DRY SAMPLES (CONTAINING <500 PPM H2O)...... 279

TABLE F-2 WATER SATURATED SAMPLE (CONTAINING 1.58 + 0.3 WT% H2O) ...... 280

xiv

ACKNOWLEDGMENTS

First and foremost, I want to thank my two advisors, Dr. Joan Brennecke and Dr.

Edward Maginn. I feel fortunate to have had the opportunity to work with two such

wonderful mentors. I hope that one I will be able to follow their example and bring

the same enthusiastic encouragement to my students.

I would also like to thank Dr. Sudhir Aki. I have been able to learn so much from

his expertise in the lab. In particular, his assistance and mentorship were an essential

part of the gas separation experiments. His willingness to stop what he’s doing and

help answer a question or offer advice is truly appreciated.

I also wish to thank the former and current members of my research group,

especially Aaron Scurto, Jacob Crosthwaite, Dan Hert, and Laurie Ropel. Whether

we were discussing research or laughing together, they really help make the time we

spend in the lab enjoyable. I thank Eric Saurer for collecting the high pressure CO2 data and Meredith Jakubowski for her assistance during the final microbalance experiments.

I also thank the other faculty and staff of the Department of Chemical and

Biomolecular Engineering, especially Dr. Mark McCready, Jeanne Davids, Marty

Nemeth, Karen Jacobs, and Jim Smith and Jim Kirksey for all their assistance.

xv I would like to thank the Center for Environmental Science and Technology for the use of the ICP-OES and Dennis Birdsell for all his help in teaching me how to use the equipment.

I also acknowledge financial support from the GE Fund Fellowship, the NSF-

Graduate Research Trainee Fellowship, and the Bayer Pre-doctoral Fellowship.

And lastly, I wish to thank my friends and family. Knowing I have their unwavering love and support makes any endeavor seem easier.

xvi

CHAPTER 1

INTRODUCTION AND BACKGROUND

1.1 Introduction

Room temperature ionic liquids have recently been getting attention as potential

environmentally benign or “green” solvents. Solvents play an extremely important

role in many industrial processes, acting as a media for chemical reactions or for

extraction of products. Typically, these solvents are volatile organic compounds or

VOCs. The high volatility of these compounds introduces several health, environmental, and economic concerns. As the VOCs volatilize, the risk of human exposure through inhalation is increased. VOCs have also been found to increase ozone depletion and smog formation. Lastly, the high volatility increases the loss of these costly solvents. Therefore, it is important to find another class of solvents that still meets the needs of industry while limiting the environmental and health risks.

1.2 Ionic Liquids

Ionic liquids (ILs) is the term used to refer to organic salts that are liquids in their pure states at ambient conditions.1, 2 Many refer to any salt with a melting point less

than 100 oC as an IL. The first water-stable ionic liquids (ILs), developed in 1992,

included 1-ethyl-3-methyl imidazolium BF4 and 1-ethyl-3-methyl imidazolium

1 3 MeCO2. Although the variety of cations and anions that could be combined to make

an ionic liquid is virtually endless; examples of some of the common classes are

shown in Figure 1.1. These classes include using imidazolium, quaternary

ammonium, pyrrolidinium, pyridinium, or tetra alkylphosphonium as the base for the

R2 R

N X R1 R2 R1 R3 N N N + + + X X

R5 R4

Imidazolium Pyridinium Pyrrolidinium

R1 R1 + X X P N+ R4 R2 R4 R2 R3 R3

Tetra alkyl phosphinium Tetra alkyl ammonium

Figure 1.1 Schematic of example classes of ionic liquids where R could be methyl, ethyl, butyl, hexyl, octyl, or decyl chains and X could be PF6, BF4, (CF3SO2)3C, (CF3SO2)2N, (CH3SO2)2N, CF3SO3, CH3CO2, CF3CO2, (CN)2N ,NO3, Cl, Br, I, etc.

cation. Possible anions, indicated by X- in Figure 1.1, could include

- hexafluorophosphate [PF6] , tetrafluoroborate [BF4], tris(trifluoromethylsulfonyl)

- - methide [(CF3SO2)3C] , bis(trifluoromethylsulfonyl) imide [(CF3SO2)2N] ,

- - - bis(methylsulfonyl) imide [(CH3SO2)2N] , triflate [CF3SO3] , acetate [CH3CO2] ,

- - - trifluoroacetate [CF3CO2] , dicyanamide [(CN)2N], nitrate [NO3] , chloride [Cl] , bromide [Br]-, or iodide [I]-.

In general, ionic liquids have many properties that are similar to conventional

organic solvents such as good solvation qualities. Additionally, they have a also wide

2 temperature range (approximately 300oC) over which they remain liquids. These

properties depend on the cation, the anion, and the substituents, therefore making it

possible to “tailor” the solvent for a particular application. Researchers have shown

that adjusting the structure of either the anion or the cation can have large effects on

many properties including melting points, viscosities, densities, and gas and liquid

solubilities.4-8 A major advantage ionic liquids have over the traditional solvents is

their vanishingly low vapor pressure.1, 2 This negligible volatility decreases the risk of

worker exposure and the loss of solvent to the atmosphere, suggesting that ionic

liquids should be inherently safer than the traditional organic solvents.

1.3 Solvent for Reactions

The bulk of ionic liquid research has focused on the use of ILs as solvents for a

variety of reactions, such as hydrogenations, hydroformylations, oxidations,

isomerizations, dimerizations, alkylations, and Diels Alder reactions.9-11 Most of

these studies find that ionic liquids work well as a reaction solvents, often comparable

or better than conventional solvents.

1.4 Physical Properties

1.4.1 Pure component properties

Pure component physical property data of ionic liquids is beginning to emerge in the literature, including properties such as viscosities,5, 12-14 densities,4, 12, 15-21 melting

points and glass transition temperatures,15,16,18-20,22-25 thermal decomposition

3 temperatures,18,19,22,24,26,27 and heat capacities.18, 28-31 Two recent reviews summarize properties of several of the most common ionic liquids.32, 33

1.4.2 Mixture properties

A clear understanding of the properties of ionic liquids in mixtures with other compounds is extremely important if ionic liquids are to be “designed” for specific applications. Of particular interest is the solubility of gases and liquids in the ionic liquids and the solubility of ionic liquids in other liquids. Note, solubilities of solid compounds in ionic liquids would also be important for relevant applications, but these are not addressed as a part of this work. Many of the reactions studied in ILs involve organic liquids or permanent or condensable gases. If a reactant gas has a low solubility in the IL, the mass transfer of the gas into the IL phase will likely be the rate-limiting factor. This limitation would require that efforts be made to increase the interfacial area and/or use high-pressure operations in order to reach the necessary concentration of gas in the IL. These efforts could affect the ability of ILs to realistically compete with conventional solvents. In addition to the importance in reactions, understanding these solubilities is necessary for assessing the usefulness of ionic liquids in other applications. Several of these applications, including liquid- liquid extraction, supercritical fluid extraction, and gas separations, are discussed in

Section 1.5.

4 1.4.2.1 Liquid solubilities

Thermodynamic properties of various liquids with different ionic liquids are

becoming more widely available in the literature. Binary temperature-composition

curves have been reported for ILs with alcohols,34-40 alkanes and aromatics,41 and water.35, 42 Ternary temperature-composition curves have been reported for ILs with

alcohols and water.35, 43, 44 Several researchers have also reported infinite dilution

activity coefficients for a variety of organic compounds in ILs.38, 45-51 Other

researchers have reported solubilities of various organics52-57 and water4-6, 19, 58-60 in different ionic liquids. One of these studies,6 which focused on how changing cation

alkyl chain length and changing anion affected water/IL mutual solubilities, is

included as part of this thesis (Chapter 5). Several researchers have also reported the

physical properties of ionic liquids mixed with water or organics.5, 19, 56, 57

1.4.2.2 Gas solubilities

Significantly less information is known about gas solubilities in ILs. Early

investigations in our laboratories showed the carbon dioxide is highly soluble in six

ionic liquids: 1-n-butyl-3-methylimidazolium hexafluorophosphate, [bmim][PF6], 1-

n-octyl-3-methylimidazolium hexafluorophosphate, [C8mim][PF6], 1-n-octyl-3-

methylimidazolium tetrafluoroborate, [C8mim][BF4], 1-n-butyl-3-methylimidazolium

nitrate, [bmim][NO3], 1-ethyl-3-methylimidazolium ethylsulfate, [emim][EtSO4], and

61, 62 N-butylpyridinium tetrafluoroborate, [N-bupy][BF4]. Bates et al. has synthesized an IL with an amine group on the cation, which they report significantly enhances the

63 CO2 solubility. One publication on hydrogenation reactions reported approximate

5 hydrogen solubilities in 1-n-butyl-3-methyl imidazolium hexafluorophosphate,

64 [bmim][PF6], and 1-n-butyl-3-methyl imidazolium tetrafluoroborate, [bmim][BF4].

However, most papers discussing reactions that involve a gas dissolved in an IL make no attempt to determine the gas concentration in the IL. Recent publications from

6 our group have presented solubilities of water vapor in [bmim][PF6], [C8mim][PF6],

7, 8, 65 and [C8mim][BF4] and other gases such as carbon dioxide, ethylene, ethane, methane, benzene, hydrogen, carbon monoxide, oxygen, nitrogen, and argon in

[bmim][PF6] and [bmim][BF4]. These results, along with additional gas solubilities

in multiple ionic liquids with differing cation and anion structures, are presented in

this thesis in Chapters 4 and 5. In works conducted both parallel and subsequent to the results presented here, other researchers have investigated the solubility of carbon dioxide in various ionic liquids,14, 66-69 hydrogen in nine imidazolium, one

70 66 phosphonium, and two pyridinium ILs, oxygen solubility in [bmim][BF4] and

71 72 [emim][Tf2N], and fluoroform in [emim][PF6].

1.4.2.3 Molecular interactions

Several studies using solvachromatic probes in ionic liquids or ionic liquid

mixtures have indicated that ionic liquids have solvent strengths comparable to polar,

aprotic solvents.33, 73-81 Investigation of gas (and liquid) solubilities in ILs can be

used further enhance the understanding of the solvation properties of these liquids.

Specifically, these solubilities can yield information about specific chemical and

molecular interactions between the gas and the IL, such as hydrogen bonding and

6 dipole-dipole, dipole-induced dipole, and dispersion forces, which will assist in

understanding the underlying solvent-behavior of ILs.

1.4.2.4 Molecular simulations

In addition to the experimental studies, several researchers have begun developing

molecular simulations to model ionic liquids and relate their chemical structures to

their thermophysical properties. Several simulations of pure ionic liquids have been

published where forcefields have been developed and physical properties have been

calculated.82-91 More recent studies have focused on modeling the structure and

physical properties of ionic liquids containing dilute concentrations of small organics

compounds,84, 85, 92 water,84, 85, 93 or gases such as carbon dioxide.94-96 Another recent study has modeled the absorption spectra of a solvachromatic probe dissolved in

97 [bmim][PF6] to calculate the solvent polarity. These modeling studies are valuable compliments to experimental studies as they allow for visualization of the structure, composition, and interactions of both pure ionic liquids and mixtures on a molecular scale, which cannot be seen easily in experiments. Studying these models can help in determining what structural factors in the ILs are governing their properties.

Predictive models will also assist in selecting and developing ionic liquids with the

desired properties for a specific application from the virtually infinite possibilities.

1.5 Additional Uses and Applications

In addition to using ILs as solvents for chemical reactions, evidence of other

possible applications is continually being reported.98 Some specific examples of

7 possible separation processes include use in liquid-liquid extraction, extractive

distillation, supercritical extraction, and gas separation systems.

1.5.1 Liquid-liquid extraction

As ILs are considered potential “green” solvents, many researchers have focused

on developing environmentally conscious techniques for recovering the reaction products. In particular, water has been suggested as another “green” solvent to use along with ILs in liquid/liquid extraction systems; both using the water to extract solutes from ILs99-102 and also the IL to extract solutes from the aqueous phase.58

Although the ILs used in these studies form two separate phases with water, they are partially miscible to some degree (i.e. some IL dissolves in the aqueous phase and some water dissolves in the IL phase). The IL in the aqueous phase is of particular concern as the environmental impact of releasing IL into the environment (in wastewater) is largely unknown. Thus far, two research groups have reported the toxicity of some ionic liquids using Daphnia magna, Vibrio fischeri, and WST-1 cell viability assays as the test organisms.103, 104 Initial toxicity measurements using

Daphnia magna indicate that the ILs with the imidazolium cation have toxicities

comparable to ammonia and phenol but greater than benzene.104 The issue of cross-

contamination was not fully addressed in the liquid-liquid extraction studies.

Other liquid-liquid extraction studies have shown that one can use ionic liquids

for the extraction of aromatics from aromatic-alkane mixtures,52 alcohols from

alcohol-alkane mixtures,105 and sulfur containing aromatics from gasoline106 and light oils.107 Again, cross-contamination due to partial miscibility between the phases and

8 more specifically, the recovery of the ionic liquid from the organic phase is likely to be an issue.

1.5.2 Extractive distillation

Ionic liquids also have potential applications as selective additives in extractive distillation. Adding an ionic liquid to an azeotropic or close-boiling mixture, such as aromatic hydrocarbons in aromatic petroleum streams, has been shown to break the azeotrope or increase relative volatility of the mixture allowing for an easier separation.108, 109

1.5.3 Supercritical extraction

Previous work in our laboratory has shown that supercritical carbon dioxide, regarded as another environmentally benign solvent, can successfully extract a wide variety of solutes from ILs.53, 54, 62 One advantage of this technique is that there is no

detectable contamination of the extractant phase by the IL. Other work in our

laboratory has shown that supercritical CO2 can be used to induce phase splitting of

organic or aqueous solutions containing ionic liquids.110, 111 This application would

be particularly relevant in terms of recovering small concentrations of ionic liquid in

an organic or aqueous stream.

1.5.4 Gas separations

Another potential application for ILs is to use them to separate gas mixtures.7, 98,

112-115 Because the ILs are non-volatile, they would not add any contamination to the

9 gas stream. This quality gives ILs an innate advantage over traditional solvents used

for absorbing gases. Whether used in conventional absorbers or in supported-liquid

membrane systems, using ILs as a gas-separation medium will require knowledge of

the pertinent gas solubilities.

1.6 Objective of Thesis

The objective of this thesis is to determine thermodynamic/phase behavior

properties by studying the phase behavior of ionic liquids with various gases and

liquids to further develop the relationships between these properties and the

molecular structure of these ionic liquids. The properties of interest include

solubilities, Henry’s constants, and enthalpies and entropies of absorption. A second objective is to show that ionic liquids can be used as a solvent to separate gas mixtures.

1.7 Outline of Chapters

Chapter 2 will cover the theory behind measuring gas solubilities in liquids. This theory includes a description of the various techniques typically used to measure gas solubilities, while focusing in more detail on those techniques used in this work.

This chapter also details the derivations for calculating thermodynamic properties such as Henry’s constants and enthalpies and entropies of absorption.

Chapter 3 details all the experimental procedures and apparatus used in this work, including a gravimetric microbalance and static high pressure apparatus for gas solubility measurements and an absorber and a membrane system for gas separation

10 measurements. This chapter also lists all the ionic liquids and gases used and their origins and purities.

Chapter 4 presents the results from the solubility measurements of a series of gases in a variety of ionic liquids with different cations and anions. The gases used range in properties from highly polar gases (e.g. water) to non-polar hydrocarbons

(e.g. methane, ethane) to inert gases (e.g. argon). Gases were also chosen to include those relevant to reactions (e.g. ethylene, hydrogen, carbon monoxide, and oxygen), supercritical extraction (e.g. carbon dioxide), and gas separations (e.g. carbon dioxide, nitrogen, methane, nitrous oxide, and nitric oxide). Conclusions are drawn as to the factors influencing gas solubilities in ILs. These factors include the structure of cation and anion on IL and the properties of the gas (e.g. polarizability, dipole moment, etc.). Comparisons are made to gas solubilities in conventional solvents.

Chapter 5 presents the results from the water and ionic liquid mutual solubilities study. These results include water vapor solubilities and liquid-liquid equilibrium measurements to study how changing the anion or changing the alkyl chain length affects the solubilities. This chapter also addresses some practical implications associated with water and ionic liquid mutual solubilities, such as ionic liquid recovery from aqueous streams and how the presence of water affects the IL behavior.

Chapter 6 focuses on the application of using ionic liquids in gas separation systems. This chapter covers the theory behind separations systems using supported- liquid membranes and absorbers. Experimental results using [bmim][PF6] to separate mixtures of carbon dioxide and methane, carbon dioxide and nitrogen, and ethylene

11 and ethane are presented as proof of the potential ILs have as a gas separation medium.

Finally, the conclusions are summarized in Chapter 7 and recommendations are made for future work.

12

CHAPTER 2

GENERAL METHODOLOGY AND THEORY

This chapter covers the general methodology for measuring gas solubilities and

calculating Henry’s constants and enthalpies and entropies of absorption. Section 2.1 discusses a variety of methods used to measure gas solubilities, including justification for choosing the methods used in this work. The section also addresses the theory and relevant derivations involved in calculating gas solubilities using the gravimetric

method. Section 2.2 discusses the important properties obtained from gas solubility

measurements, including Henry’s constants (Section 2.2.1) and enthalpies and

entropies of absorption (Section 2.2.2).

2.1 Methods for Measuring Gas Solubilities

There are many factors that can influence accuracy when measuring gas

solubilities in liquids.116 The purity of the gas and the liquid is important because

any impurities could affect the results. Fully degassing the solvent prior to the

experiment is necessary to ensure that the gas absorbed as measured during the course

of the experiment is the true gas solubility. Accurate measurement of the relevant

parameters such as temperature, pressure, volume, and/or mass is extremely

important, as is precise control of any adjusted parameters (e.g. temperature and

13 pressure control). Accurate gas solubility measurements depend on attaining the true equilibrium value of absorbed gas. Finally, an accurate method to ascertain the true amount of dissolved gas must be developed for the particular system used. The following sections will address various experimental methods for measuring gas solubilities and how these factors are addressed.

2.1.1 Volumetric and pressure drop methods

The most typical methods for measuring the solubility of gases in liquids are modifications on one of two techniques, both occurring at constant temperature. In the first technique, often referred to as the pressure-drop method, the volume is held constant, and the pressure drop is monitored as the gas absorbs into the liquid. In the second case, frequently called the volumetric technique, the pressure is kept constant, and the volume change needed to maintain the pressure as the gas is absorbed by the liquid is measured. In either case, the pressure, temperature, and volume before absorption and then following absorption are known. Therefore, the amount of gas absorbed by the liquid can be calculated, frequently by using an equation of state to convert pressure, volume, and temperature to moles.

Many modifications on the apparatus used for these techniques have been made to improve the different aspects of the measurements, such as improving equilibration time by changing the stirring method or gas/liquid interface area, improving the degassing of the solvent method, or improving the temperature, volume, or pressure measurement and control. Reviews by Clever and Battino116 and Wilhelm117 address many of these modifications. In general, the majority of the gas solubilities in liquids

14 reported in the literature have been measured using the fundamental concepts

involved in either the volumetric (isobaric and isothermal) or the pressure drop

(isochoric and isothermal) techniques.

Several groups have reported gas solubility measurements in ionic liquids using

variations on these techniques.61, 66, 67 In the present work, only the gas solubility

measurements reported in Chapter 5 were made using the volumetric technique in an

apparatus designed for high pressure applications.118 The specifics of this apparatus and the experimental procedure are discussed in Section 3.3. A very thorough discussion of the methodology for calculating the gas solubilities for that particular apparatus can be found in a previous work.119

2.1.2 Gas chromatography

Gas chromatography can be used to measure gas solubilities in liquids in two different ways.116 In the extractive technique, the solvent is saturated with the gas of

interest and then coated on a column. A non-absorbing carrier gas is passed though

the column to extract the gas of interest. The carrier gas phase is analyzed in the GC

to determine the amount of solute gas removed. In this technique, it is important to

saturate the carrier gas with the solvent prior to flowing it through the column to

avoid removing the solvent in the column in the carrier gas phase. In the second gas

chromatographic technique, gas solubilities are measured in the solvent at infinite

dilution by first coating the pure (degassed) solvent on a column and then flowing a

non-absorbing carrier gas containing the solute of interest. The amount of gas

15 absorbed by the solvent can be calculated from the retention time of the solute in the

column.

Several researchers have used these techniques to measure the infinite dilution

activity coefficients of organic compounds in a variety of ionic liquids.38, 46-51, 120 It is

interesting to note that in the work using the extractive technique120 (also called the

dilutor technique), the pre-saturation of the carrier gas step has been eliminated due to

the non-volatile nature of the ionic liquid. All of these studies have been limited to

investigating organic compounds as the solutes; there have been no reported studies

using gas chromatography to measure other gas solubilities in ionic liquids.

2.1.3 Gravimetric method

In the gravimetric method, the gas solubility is determined by measuring the change in weight of the sample upon absorption. This technique is commonly used for adsorption of gases onto solids but rarely is used for absorption of gases into liquids because any loss of the liquid due to evaporation affects the final weight of the sample. However, due to the non-volatile nature of the ionic liquids, the gravimetric technique works well for these systems and is the technique used for the majority of the gas solubility measurements in this work.

2.1.3.1 Buoyancy correction

An important factor to account for when measuring gas solubilities by the gravimetric technique is the effect of buoyancy on the measurements. In the apparatus used in this work, a counterweight side symmetric to the sample side was

16 used to minimize these effects, but they still need to be taken in to consideration.

Figure 2.1

Weight Reading

Hangdown Chains

FB(II) FB(I) II I

FW(II) FW(I)

Counterweight Sample and and Bucket Bucket

Figure 2.1 Schematic of a balance used in the gravimetric techniques with symmetric sample (I) and counterweight (II) sides. Also shown are the directions of the relevant forces (FB indicates forces due to buoyancy and FW indicates forces due to weight/gravity).

shows the two sides of the balance along with the directions of the relevant forces. A

total force balance on the microbalance components yields the following equation:

∆W = []FW (I ) − FW (II) − [FB (I ) − FB (II)] (2.1)

17 where the subscripts W and B indicate forces due to weight and buoyancy,

respectively, for either the sample side (I) or the counterweight side (II), and ∆W is

the overall change in weight. Substituting in the appropriate relationships for force

due to weight and force due to buoyancy, Equation 2.1 can be rewritten as

∆W = g ⋅ (ms + ma + m I − mc − m II − ρ b ⋅ (V s + V a + V I −V c −V II )) (2.2) where ∆W is the weight change upon absorption, g is the gravitational constant, ms is the mass of the sample, ma is the mass of the absorbed gas, mI is the mass of the

balance components on the sample side, mc is the mass of the counterweight, mII is the mass of the balance components on the counterweight side, ρb is the bulk gas density, Vs is the volume of the sample, Va is the volume of the absorbed gas, VI is the

volume of the balance components on the sample side, Vc is the volume of the

counterweight, and VII is the volume of the balance components on the counterweight side. Prior to adding the sample and under vacuum conditions (i.e. no buoyancy effects are present), the balance is “zeroed”, making the following equation true:

m s + m I = mc + m II (2.3)

Also assuming there is negligible volume expansion of the sample upon absorption,

or the volume of the absorbed gas has an insignificant contribution to buoyancy

effects relative to the contribution from the sample volume (i.e. Vs >> Va ~ 0),

Equations 2.2 and 2.3 can be simplified to

∆W = ma − ρ b ⋅ (V s + V I − V c − V II ) (2.4) g

18 The volumes of the balance components and buckets (V I , V c , and V II ) will remain

constant regardless of the sample used, so these can be combined into one volume

term for simplicity:

V 0 = V I −V c −V II (2.5)

Simple rearrangement of equations 2.4 and 2.5 yields the following equation:

∆W m a = + ρ b * (V s + V 0 ) (2.6) g where the total mass of gas absorbed by the liquid can be calculated by subtracting off a buoyancy correction from the mass change recorded by the balance. The experimental procedures used to account for the buoyancy are discussed in the following chapter, in Section 3.2.2.

2.1.3.2 Advantages of gravimetric method

There are several advantages of using a gravimetric microbalance to measure gas solubilities. As mentioned earlier, ensuring that equilibrium has been reached is an important issue when measuring gas solubilities. The gravimetric balance allows the user to monitor the mass change as time progresses; as equilibrium is reached, the mass change will approach zero. Once the mass no longer changes, the sample is at equilibrium. Ensuring the initial liquid has been fully degassed prior to the measurement is also an important factor in order to determine how much gas is dissolved in the sample. Again, the ability to monitor the mass change as time progresses allows the user to ensure that the mass has stopped decreasing during the degassing step before proceeding to the solubility measurement. These advantages,

19 and several others specific to the particular microbalance used in this work, will be

elaborated on further in the following chapter, in Section 3.2.

2.1.4 Other techniques

Techniques other than those discussed above are occasionally used for measuring

gas solubilities in liquids.116 Mass spectrometry can be used to analyze ratios of

gases dissolved in solvents. Chemical analytical techniques can sometimes be used to

determine the solubility of specific gases by analyzing for reaction products, but these

techniques only apply to specific situations. Some gas-specific sensors are

commercially available, such as electrochemical sensors to measure dissolved oxygen

content, but again, those sensors only work for a specific gas.

2.2 Thermodynamic Properties

Several thermodynamic properties can be calculated once gas solubilities are

known, such as Henry’s constants, infinite dilution activity coefficients, and

enthalpies and entropies of absorption.

2.2.1 Derivation for Henry’s constants

Henry’s constants are proportionality constants relating the partial pressure of a gas to its solubility in a liquid at infinitely dilute conditions. There are several conventional ways Henry’s constants are defined in the literature; the following paragraphs show how to derive the Henry’s law constant and infinite-dilution activity coefficient based on the definitions used in this work.121

20 The Henry’s law constant is defined as

L lim f1 H1()T, P ≡ (2.7) x1 → 0 x1

L where f1 is the fugacity of the gas dissolved in the liquid phase. The Henry’s constant depends on temperature, but is relatively insensitive to pressure, especially over the pressure ranges examined in the present work. Knowing the fugacity of the gas in the liquid phase must be equal to the fugacity of the gas in the gas phase and approximating the gas phase fugacity as the gas phase pressure, the following form of

Henry’s law can be obtained:

P1 = H1(T )⋅ x1 (2.8) where P1 is the partial pressure of the gas and H1(T) will have units of pressure and is inversely proportional to the mole fraction of gas in the liquid.

The Henry’s constant is also directly related to the infinite dilution activity coefficient and the vapor pressure of the gas. The equilibrium condition for a binary mixture of a gas (1) and ionic liquid (2) can be expressed as121

o φ1 ⋅ y1 ⋅ P = γ 1 ⋅ x1 ⋅ f1 (2.9)

Assuming the vapor phase is ideal (φ1 = 1), the IL is non-volatile (y1 = 1), and taking

o sat sat f1 = P1 , where P1 is the vapor pressure of pure gas at temperature T, Equation 2.9 may be re-written as

sat P = γ 1 ⋅ x1 ⋅ P1 (2.10)

The activity coefficient of the gas in the IL phase, γ1, may therefore be determined directly by measuring the mole fraction of gas dissolved in the IL as a function of the pressure of gas above the IL solution.

21 Given the assumptions used for Equation 2.10, Equation 2.7 can be rearranged as

lim sat H1()T = γ 1 ⋅ P1 (2.10) x1 → 0 or that

H (T ) γ ∞ = 1 (2.11) 1 sat P1

∞ where γ1 is the infinite-dilution activity coefficient of the gas in the IL.

2.2.2 Derivation for enthalpy and entropy of absorption

Enthalpies and entropies of absorption can be found by considering the temperature effects on gas solubilities. The enthalpy yields information about the strength of interaction between the liquid and dissolved gas, whereas the entropy indicates the level of ordering that takes place in the liquid/gas mixture. These properties can be determined from the following thermodynamic relations122

 ∂ ln x   ∂ ln a  ig 1  1  ∆h1 = h1 − h1 = RT    (2.12)  ∂ lnT  P  ∂ ln x1  P,T

 ∂ ln x   ∂ ln a  ig 1  1  ∆s1 = s1 − s1 = R    (2.13)  ∂ lnT  P  ∂ ln x1  P,T

ig where h1 and s1 are the partial molar enthalpy and entropy of the gas in solution, h1

ig and s1 are the enthalpy and entropy of the pure gas in the ideal gas phase, and a1 is the activity of the gas in the solution:

a1 = γ 1 ⋅ x1 (2.14)

22 Equations 2.12 and 2.13 are equivalent to

 ∂ ln P  ∆h = R  (2.15) 1  ∂()1 T    x1

 ∂ ln P  ∆s = −R  (2.16) 1 ∂ lnT   x1 which give ∆h1 and ∆s1 at a specific mole fraction of gas in the liquid (x1). In the

Henry’s law regime (i.e. when γ1 is independent of x1), the last term in Equations 2.12 and 2.13 is unity. Therefore, those equations can be reduced to their familiar van’t

Hoff forms121

 ∂ ln x1   ∂ ln H1  ∆h1 = −R  = R  (2.17)  ∂()1 T  P  ∂()1 T  P

 ∂ ln x1   ∂ ln H1  ∆s1 = R  = −R  (2.18)  ∂ lnT  P  ∂ lnT  P yielding ∆h1 and ∆s1, valid at infinite dilution. Equations 2.17 and 2.18 will give the same ∆h1 and ∆s1 as given by Equations 2.15 and 2.16 as the x1 becomes small enough to be in the infinite dilution range.

23

CHAPTER 3

EXPERIMENTAL DETAILS

This chapter will cover the details of the various experiments conducted as part of this work. The first section describes all the chemicals and gases used. In Section

3.2, the apparatus used to make the low pressure gas solubility measurements is described. The apparatus used for high-pressure gas solubilities is described in

Section 3.3. Results from this apparatus are only included in Chapter 5. Section 3.4 discusses the water/ionic liquid liquid-liquid equilibrium experiments, set-up, and analysis. Section 3.5 discusses experiments using activated carbon to adsorb ionic liquid. The gas separation experiments and apparatuses are described in Section 3.6.

3.1 Materials

3.1.1 Ionic liquids

Fourteen different ionic liquids, listed in Table 3.1, were used in this work; several of which were obtained from more than one source and synthesized or purified using different techniques. Over the duration of these experiments, more information has become available regarding impurities in the ionic liquids, particularly what they are likely to be, how to test for them, and how to remove them.5, 123 These impurities range from colored compounds to left-over starting

24 TABLE 3.1

IONIC LIQUIDS STUDIED WITH THEIR SHORTHAND NOTATION

AND STRUCTURE

Ionic Liquid Shorthand Name Structure F 1-n-butyl-3-methylimidazolium [bmim][PF6] F P F hexafluorophosphate N + N F F F 1-n-butyl-2,3-dimethylimidazolium [bmmim][PF6] F hexafluorophosphate F P F N + N F F F F 1-n-octyl-3-methylimidazolium [C8mim][PF6] F F hexafluorophosphate N N P + F F F 1-n-butyl-3-methylimidazolium [bmim][BF4] F N N B tetrafluoroborate + F F F 1-n-butyl-2,3-dimethylimidazolium [bmmim][BF4] tetrafluoroborate F N N B + F F F 1-n-octyl-3-methylimidazolium [C8mim][BF4] F N N B tetrafluoroborate + F F F O 1-ethyl-3-methylimidizolium [emim][Tf2N] N O S S bis(trifluoromethylsulfonyl) imide N N F F + O O F F F F 1-ethyl-2,3-dimethylimidizolium [emmim][Tf2N] O N O bis(trifluoromethylsulfonyl) imide S S N N F F + O O F F F F O 1-n-butyl-3-methylimidazolium [bmim][Tf2N] N O S S N N F F bis(trifluoromethylsulfonyl) imide + O O F F F F methyl-tri-butyl ammonium [MeBu3N][Tf2N] + O N N O bis(trifluoromethylsulfonyl) imide S S F F O O F F F F hexyl-tri-butyl ammonium [HxBu N][Tf N] O 3 2 + N O bis(trifluoromethylsulfonyl) imide N S S F F O O F F F F Methyl-butyl pyrrolidinium [MeBuPyrr][Tf2N] O + N O N S S bis(trifluoromethylsulfonyl) imide F F O O F F F F 1-n-butyl-3-methylimidazolium [bmim][NO3] O O N N N nitrate + O tri-isobutyl-methyl phosphonium [iBu3MeP][TOS] O + paratoluene sulfonate P S O O

25

materials to degradation products. Most of the samples in this work were purified according to the state-of-the-art techniques conventionally used for ILs at the time of the experiments, although some samples obtained from other laboratories were too small to be able to purify or analyze for impurities. Occasionally, experiments were repeated with new, higher purity ionic liquids following the discovery of potential impurities in the ionic liquid used previously. Any differences seen in the results due to changes in the purity level are described in the chapters on those specific results.

The purity of each sample, as best known, is reported below. All samples were kept under an atmosphere of nitrogen to minimize any water absorption.

[bmim][PF6]: The 1-n-butyl-3-methylimidazolium hexafluorophosphate used in the gas solubility measurements was obtained from Sachem with a reported residual chloride of less than 3 ppm and was used as received. It was a clear liquid with a slight yellow tint. The [bmim][PF6] used in the gas separation experiments was synthesized by Timothy Morrow at the University of Notre Dame using the standard synthesis technique.5 The precursor 1-n-butyl-3-methylimidizolium chloride,

[bmim][Cl], was made by reacting 1-methylimidazole with an excess of 1- chlorobutane. The [bmim][Cl] was reacted with hexafluorophosphoric acid (HPF6) to form the desired product of [bmim][PF6]. It was washed with water to remove any residual acid and chloride, mixed with activated carbon to remove any colored compounds, and dried under vacuum at 70 oC for several days.

[C8mim][PF6]: Samples of 1-octyl-3-methylimidazolium hexafluorophosphate sample were obtained from two different locations: Sachem and Professon Ken

26 Seddon’s laboratory at The Queen’s University of Belfast (QUB). The synthesis method used by Professor Seddon’s group for this compound is described elsewhere.124 The Sachem sample was reported to have 14 ppm chloride, whereas the

QUB sample contained significant chloride: 1400 + 100 ppm, as determined using a spectrophotometric method.125, 126 This value was qualitatively confirmed by measurements in Professor Seddon’s laboratories. Both samples were clear liquids with slight yellow tints.

[C8mim][BF4]: The 1-octyl-3-methylimidazolium tetrafluoroborate was obtained from Professon Ken Seddon’s laboratory (QUB); the synthesis method is described elsewhere.24 This sample was found to contain 950 + 100 ppm using the spectrophotometric method.125, 126 Again, this value was qualitatively confirmed by measurements in Professor Seddon’s laboratories. After repeated water washings, the residual chloride in the QUB [C8mim][BF4] sample was reduced to less than 300 ppm. The sample was a clear liquid with a slight yellow tint.

[bmim][BF4]: One sample of 1-n-butyl-3-methylimidazolium tetrafluoroborate used was obtained from Professor Tom Welton and coworkers at Imperial College,

London. They report a chloride content of <1.4 ppm.127 The other sample of

[bmim][BF4] used was synthesized and purified by Jacob Crosthwaite at the

University of Notre Dame.18 The starting material of 1-n-butyl-3-methylimidizolium bromide, [bmim][Br], was made by reacting 1-methylimidazole with an excess of 1- bromobutane, under nitrogen. The [bmim][Br] was then reacted with an excess ammonium tetrafluoroborate in a water/dichloromethane biphasic system to form

[bmim][BF4] by anion exchange. The residual ammonium bromide is removed in the

27 water phase and subsequent water washings. Any colored compounds are removed using activated carbon. The water and dichloromethane are removed by vacuum.

The final concentrations of bromide and ammonium in the [bmim][BF4] were measured using an Oakton Ion 510 Series pH/mV/Ion/oC meter with Cole-Palmer

- + specific probes (27502-05 for Br and 27502-03 for NH4 ) and were found to be less than 8 ppm bromide and less than 18 ppm ammonium. Both samples were clear, colorless liquids.

[bmmim][BF4]: The 1-n-butyl-2,3-dimethylimidazolium tetrafluoroborate was obtained from the laboratory of Professor Tom Welton at Imperial College, London.

They report a chloride content of <1.4 ppm.127 It was a clear, colorless liquid and was used as received.

[bmmim][PF6]: The samples of 1-n-butyl-2,3-dimethylimidazolium hexafluorophosphate, were obtained from the laboratory of Professor Tom Welton at

Imperial College, London and from Solvent Innovation. The sample from Professor

Welton’s lab was a clear, colorless liquid with a reported chloride content of <1.4 ppm and was used as received.127 The sample from Solvent Innovation was a yellow solid, which was easily melted and remained liquid at room temperature. This sample was purified by dissolving it in dichloromethane and mixing with activated carbon for 24+ hours. The carbon was then filtered from the sample, and the dichloromethane was removed by evaporation. The final liquid still retained a pale yellow tint.

[emim][Tf2N]: Samples of 1-ethyl-3-methylimidizolium bis(trifluoromethylsulfonyl) imide were obtained from Covalent Associates (99+%

28 electrochemical grade) and from Professor Peter Wasserscheid at the Institut für

Technische Chemie und Makromolekulare Chemie der RWTH Aachen. Both samples were clear and colorless and used as received.

[emmim][Tf2N]: Samples of 1-ethyl-2,3-dimethylimidizolium bis(trifluoromethylsulfonyl) imide were obtained from Covalent Associates (99+% electrochemical grade) and from Professor Peter Wasserscheid at the Institut für

Technische Chemie und Makromolekulare Chemie der RWTH Aachen. Both samples were clear and colorless and used as received.

[bmim][Tf2N]: The samples of 1-n-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide was purchased from Covalent Associates (99+% electrochemical grade). It was a clear, colorless liquid. Experiments were conducted on samples as received and again following a purification process consisting of dissolving the IL in dichloromethane and washing with water to remove any acid or halide. The IL dissolved in dichloromethane was also contacted with activated carbon for 24+ hours.

[bmim][NO3]: The 1-n-butyl-3-methylimidazolium nitrate was synthesized by

Professor Joan Brennecke by reacting [bmim][Cl] with AgNO3. The silver nitrate precipitated out of solution; chloroform was used to precipitate remaining colloidal silver. The remaining IL was a clear, colorless liquid and had residual silver content of 0.50 + 0.02 wt%, measured by a Perkin Elmer Optima 3300 Axial View

Inductively Coupled Plasma Optically Emitting Spectrometer (ICP-OES).

The ICP-OES is located in the Center for Environmental Science and Technology

(CEST) at the University of Notre Dame. The ICP-OES has a silver detection limit of

29 2 ppb. Scans were collected at two different wavelengths to detect the silver: 243.778 nm, and 224.874 nm. Six aqueous silver nitrate solutions, ranging in concentration from 2.3 × 10-5 wt% to 0.29 wt% silver, were used to develop a calibration curve for detecting silver concentration, as given in Equations 3.1 and 3.2:

243.778 nm:

Conc (wt% Ag) = 1.29 × 10-7 × (Peak Intensity) + 3.67 × 10-4 (3.1)

224.874 nm:

Conc (wt% Ag) = 9.44 × 10-7 × (Peak Intensity) + 1.21 × 10-3 (3.2)

These calibration curves are shown in Appendix A. Three replicates of each concentration at both wavelengths were measured; the standard deviation for each calibration is less than 3%. Three replicates were also completed for the ionic liquid sample at both wavelengths; the deviation between those concentrations was, again, less than 3% error, which was taken to be the error in the measurement.

[MeBu3N][Tf2N]: A sample of methyl-tri-butyl ammonium bis(trifluoromethylsulfonyl) imide was obtained from Dr. Pedi Neta at the National

Institute of Standards of Technology (NIST) in Gaithersburg, MD. The sample was a clear, colorless liquid and was used as received. The synthesis method and purities of starting materials are reported elsewhere.128

[HxBu3N][Tf2N]: A sample of hexyl-tri-butyl ammonium bis(trifluoromethylsulfonyl) imide was obtained from Dr. Pedi Neta at the National

Institute of Standards of Technology (NIST) in Gaithersburg, MD. The sample was a clear, colorless liquid and was used as received. The synthesis method and purities of starting materials are reported elsewhere.129

30 [MeBuPyrr][Tf2N]: A sample of methyl-butyl pyrrolidinium bis(trifluoromethylsulfonyl) imide was obtained from Dr. Pedi Neta at the National

Institute of Standards of Technology (NIST) in Gaithersburg, MD. The sample was a clear, colorless liquid and was used as received. The synthesis method and purities of starting materials are reported elsewhere.129

[iBu3MeP][TOS]: A sample of tri-isobutyl-methyl phosphonium paratoluene sulfonate was obtained from Cytec. This sample was a brown liquid and contained significant impurities, most likely from starting materials. This sample was heated at

70 oC under vacuum for several days. Approximately 8 to 10 wt% of volatile material was removed before using the sample.

3.1.2 Gases

Carbon dioxide (CO2) was from Scott Specialty Gases, with a purity of 99.99%.

Methane (CH4) and ethane (C2H6) were both from Matheson Gas Products, with purities of 99.97% and 99.99%, respectively. The remaining gases were all purchased from Mittler Supply Company with the following purities: ethylene (C2H4) had a purity of 99.5%, hydrogen (H2) had a purity of 99.999%, carbon monoxide

(CO) had a purity of 99.97%, oxygen (O2) had a purity of 99.99%, nitrogen (N2) had a purity of 99.999%, argon (Ar) had a purity of 99.999%, and nitrous oxide (N2O) had a purity of 99.0%. The gas mixtures of 10 mol% CO2 in N2, 10 mol% CO2 in

CH4, and a 50 mol% mixture of C2H4 and C2H6 were also purchased from Mittler

Supply Company. The water (H2O) used in the water vapor solubility experiments and the liquid-liquid equilibrium experiments was deionized using a Milli-Q water

31 filtration system from Millipore. The benzene (C6H6) was purchased from Aldrich with a reported purity of 99.9+%; it was redistilled prior to use.

3.2 Gravimetric Microbalance

The gas solubility measurements were made using an Intelligent Gravimetric

Analyser (IGA 003), seen in the photograph in Figure 3.1, from Hiden Analytical.

The IGA is a gravimetric microbalance which is capable of measuring absorption isotherms using either vapors in static mode or gases in flowing or static modes. This apparatus has been previously used in adsorption experiments and a detailed description of the apparatus can be found elsewhere.130

Figure 3.1 Gravimetric microbalance

32

3.2.1 Experimental procedure

A detailed schematic of the apparatus and its individual components is shown in

Figure 3.2. The microbalance consists of a weighing mechanism (C.I. Electronics 5 gram head) with sample pan and counterweight which have been symmetrically configured to minimize buoyancy effects. The balance has a 1 µg stable resolution.

Figure 3.2 Schematic of the gravimetric microbalance

33 The sample buckets are attached to the weighing mechanism by gold hang-down chains. Two different types of sample buckets were used in these experiments: a conical, stainless steel bucket and a cylindrical, quartz bucket (shown in Figure 3.3).

Figure 3.3: Quartz sample bucket containing an ionic liquid sample for the microbalance apparatus

The same type of bucket is used on both the sample and counterweight sides (i.e. either both were stainless steel buckets or both were quartz buckets). With either bucket, sample sizes of approximately 50 to 75 mg of ionic liquid sample were used.

After hanging the loaded sample bucket on the chains, the chamber was sealed using a copper gasket. The sample was dried and degassed by first pulling a coarse vacuum on the sample with a diaphragm pump (MZ 2d, Vacuubrand) and then fully evacuating the chamber to approximately 10-9 bar with a turbomolecular pump (TMU

064, Pfeiffer). The sample was heated to about 75 °C during this process with an

34 external furnace (SFL TF 1042, Fisher Scientific) in the early water vapor experiments or to 50 oC using a water jacket connected to a constant temperature bath

(RTE-111, Neslab) in the other experiments. As described later, the lower temperature was used to decrease the risk of sample decomposition. This activation period typically took between 4 and 8 h, during which time the sample mass slowly decreased as residual water and gases were driven off. Once the mass had stabilized for 30 min, the sample was considered fully degassed, and the absorption measurements were initiated.

During the experiments, the chamber temperature was controlled using the water jacket and constant temperature bath. The sample temperature was monitored with a type K platinum thermocouple placed inside the sample chamber and automatically maintained within 0.1 °C of the setpoint. Once the desired temperature of the sample was reached, gas or vapor was introduced into the sample chamber through a leak valve until a predetermined pressure was reached. Pressures from 0-100 mbar were measured using a capacitance manometer (Baratron 626, MKS), and above 100 mbar a strain gauge (PDCR 910, Druck) was used. The pressure was maintained within

0.06% of the setpoint through control of the leak valve and exhaust valve. As the vapor or gas entered the chamber, the sample mass increased as gas absorbed into the sample, as shown in Figure 3.4. The weight change was monitored until the mass did not change significantly for at least 15 min, after which the sample was deemed to have reached equilibrium, thus yielding a single point on the absorption isotherm.

This process was repeated through a predetermined set of pressures until the maximum pressure was reached (some fraction of the vapor pressure at the prevailing

35 temperature for vapors or 13 bar for gases). Following this, the process was reversed; the gas pressure above the sample was gradually reduced in a series of small desorption steps, during which the decrease in sample mass was recorded. Upon completion of this process, a complete absorption / desorption isotherm was obtained, as shown in Figure 3.5. The degree of hysteresis between the two isotherm branches gives an indication of the accuracy of each value. After the completion of an absorption / desorption loop, the sample was dried and degassed and the mass compared with the initial mass to confirm that the ionic liquid did not volatilize or decompose during the run. Even after performing multiple absorption / desorption experiments over several months, none of the samples exhibited a detectable loss in mass.

76.5 26

Pressure 76.4 22 ) g ) r m a ( Mass b

ss 76.3 (m

18 re Ma essu r mple 76.2 P Sa 14

76.1 10 0 10203040506070 Elapsed Time (min)

Figure 3.4 Mass change in [bmim][PF6] as a function of time due to water absorption while increasing the pressure from 20 mbar to 25 mbar

36 0.4

10 oC - absorption 10 oC - desorption 0.3 on ti 0.2 Frac e l Mo

o 0.1 50 C - absorption 50 oC - desorption

0.0 02468101214 Pressure (bar)

Figure 3.5 Absorption and desorption isotherms for CO2 solubility in [bmim][Tf2N] at 10 oC and 50 oC

3.2.2 Accounting for buoyancy

An important factor in performing these experiments is to carefully account for buoyancy effects in the system, even when a symmetric balance is used. An accurate calculation of the buoyancy effects is especially important for the low solubility gases, as the buoyancy is a large percentage of the measured weight change. As shown in the previous chapter (Section 2.1.3.1), accurate buoyancy calculations require a knowledge of the volume of the balance components (sample and counterweight buckets, counterweight, and hang-down chains), the volume of the sample, and the density of the bulk gas phase.

Since the balance components do not change from run to run, it is not necessary to know the exact volume of each individual component, but rather the volume

37 difference between the total components on the sample side (hang-down chains and sample bucket) and those on the counterweight side (hang-down chains, counterweight, and counterweight bucket). This difference was defined as Vo in

Equation 2.5. If Vo is a positive value, the volume of the components on the sample side is greater than that on the counterweight side. If it is negative, the volume of the counterweight components is larger. The procedure for determining this volume difference, as developed in previous works with this microbalance,130, 131 requires the measurement of an isotherm without any absorption, so any change in “mass” detected by the balance is completely due to buoyancy effects. This is accomplished by running an experiment with an empty bucket using a non-absorbing gas, such as helium. An example plot of the resulting isotherms is shown in Figure 3.6 for a quartz bucket with both increasing and decreasing helium pressure. A positive slope

6e-5 Increasing Helium Pressure

) Decreasing Helium Pressure 4e-5 (g ading Re

2e-5 s s a M e 0 alanc ob r c i -2e-5 M

-4e-5 0.0000 0.0005 0.0010 0.0015 0.0020 0.0025 Density of Bulk Gas (g/cc)

Figure 3.6 Buoyancy scan using helium for quartz sample bucket 1

38 shows an “increase in mass” on the sample, which means the buoyancy effects on the counterweight are greater than those on the sample side, since buoyancy forces work in the opposite direction of weight forces. Therefore, the slope of these isotherms is equivalent to –Vo. All the buckets in used in this work yield a negative value for Vo, as shown in Table 3.2.

TABLE 3.2

VOLUME DIFFERENCES OF THE BALANCE COMPONENTS a

Sample Bucket Vo(cm3) Stainless Steel Bucket -0.0132 Quartz Bucket 1 -0.0335 Quartz Bucket 3 -0.0268 Quartz Bucket 4 -0.0173 Quartz Bucket 5 -0.0275

a determined by helium buoyancy scans for various sample buckets

The volume of the ionic liquid sample is found from its density, therefore the density of the IL sample must be known accurately. Table 3.3 gives the linear dependence of density on temperature for each of the ionic liquids used in this work.

The temperature-dependent densities used for [bmim][PF6], [C8mim][PF6], and

[C8mim][BF4] were found from a linear fit of the data reported by Gu and

Brennecke.17 The temperature-dependent densities of the other ionic liquids, with the exception of the [bmim][NO3] and [iBu3MeP][TOS], were measured by either Daniel

Hert or Dr. Sudhir Aki, at the University of Notre Dame, using either a 1 mL pycnometer18 or a 250 µL syringe, which yield density values with errors of less than

39 0.5%. The density relationship for [bmim][NO3] was obtained from data reported in

12 the literature, and the [iBu3MeP][TOS] densities were reported by Cytec.

In the buoyancy calculations discussed in Section 2.1.3.1, the assumption is made that the volume of the sample does not change during the course of the run. Although typical organic solvents usually do expand upon gas absorption, previous volume expansion measurements with these ionic liquids have reported very little volume expansion, even when large amounts of gas has been absorbed.61 For example,

Blanchard and Brennecke report the volume increased approximately 1% to 5% in a

61 CO2 / [bmim][PF6] mixture containing 30 mol% CO2. Molecular simulations have calculated a volume expansion of approximately 1.5% for 10 mol% CO2 in either

95 [bmim][PF6] or [bmmim][PF6]. Since the solubilities of gases presented in the following chapters rarely surpass 30 mol%, the effects of volume expansion can be neglected.

The densities of the bulk phase gas were calculated using the following equations of state: the ideal gas law for H2O, C6H6, NO, and N2O, equations of state developed

132 133 134 135 by Wagner and coworkers for CO2, O2, N2, and Ar and the Benedict-Webb-

136, 137 Rubin equation of state for C2H4, C2H6, CH4, H2, and CO.

40

TABLE 3.3:

TEMPERATURE-DEPENDENT DENSITY RELATIONSHIPS FOR THE

IONIC LIQUIDS

Ionic Liquid Density (g/cm3) 17 3 -4 o [bmim][PF6] ρ(g/cm ) = (-8.10 × 10 ) × T( C) + 1.38 18 3 -3 o [bmmim][PF6] ρ(g/cm ) = (-1.37 × 10 ) × T( C) + 1.27 17 3 -4 o [C8mim][PF6] ρ(g/cm ) = (-7.11 × 10 ) × T( C) + 1.24 18 3 -4 o [bmim][BF4] ρ(g/cm ) = (-6.43 × 10 ) × T( C) + 1.22 18 3 -3 o [bmmim][BF4] ρ(g/cm ) = (-1.27 × 10 ) × T( C) + 1.13 17 3 -4 o [C8mim][BF4] ρ(g/cm ) = (-6.64 × 10 ) × T( C) + 1.11 18 3 -4 o [emim][Tf2N] ρ(g/cm ) = (-9.61 × 10 ) × T( C) + 1.54 18 3 -4 o [emmim][Tf2N] ρ(g/cm ) = (-9.09 × 10 ) × T( C) + 1.51 18 3 -4 o [bmim][Tf2N] ρ(g/cm ) = (-9.15 × 10 ) × T( C) + 1.46 3 -4 o [MeBu3N][Tf2N] ρ(g/cm ) = (-7.57 × 10 ) × T( C) + 1.29 3 -4 o [HxBu3N][Tf2N] ρ(g/cm ) = (-7.91 × 10 ) × T( C) + 1.21 3 -3 o [MeBuPyrr][Tf2N] ρ(g/cm ) = (-1.04 × 10 ) × T( C) + 1.42 12 3 -4 o [bmim][NO3] ρ(g/cm ) = (-7.00 × 10 ) × T( C) + 1.18 3 -5 o [iBu3MeP][TOS] ρ(g/cm ) = (-5.00 × 10 ) × T( C) + 1.06

3.2.3 Ensuring equilibrium

Another important factor is to ensure sufficient time is allowed for the system to reach equilibrium. The ionic liquid samples used in these studies are somewhat viscous, so the diffusion of gas into the liquids can be quite slow. A major advantage of using a microbalance for these measurements is that the weight change can be monitored as a function of time, as shown earlier in Figure 3.4 for water vapor dissolving in [bmim][PF6]. Monitoring the weight change over time allows easy determination of the time necessary for equilibrium to be reached by noting how long is needed before the mass stops increasing significantly. The assurance of attaining

41 equilibrium by monitoring mass versus time is important during the run as well as prior to the run to ensure the sample is sufficiently dried.

Another advantage of this apparatus in terms of ensuring equilibrium is the ability to collect both absorption and desorption branches of the isotherms, as shown earlier in Figure 3.5. The two branches provide upper and lower bounds for the true equilibrium value; during absorption, the equilibrium solubility is approached starting from a lower solubility, so if insufficient time is allowed, the measured solubility will be too low, whereas during desorption, the value is approached from a higher value and would be too high if insufficient time is allowed. Therefore, the degree of hysteresis between the branches indicates how close the measurements are to the true equilibrium. The two isotherms in Figure 3.5 show an example of the largest degree of hysteresis seen in these experiments (10 oC) as well as the little to no hysteresis (50 oC) that was usually seen. The equilibrium time for all samples in this work ranged from 60 to 180 min per point, depending on the ionic liquid, the gas or vapor, and the sample temperature.

3.2.4 Error analysis

There are several sources of uncertainty in the microbalance experiments. The uncertainties in measuring both the pressure and the mass are extremely small, about

0.06% and 0.0013% respectively. The bulk of the error in the solubility isotherms results from the uncertainty in achieving equilibrium. As described previously, the absorption and desorption branches of the isotherms serve as upper and lower bounds for the true equilibrium values. Typically, the hysteresis between the absorption and

42 desorption isotherms is less than 1 or 2%. However, for a few runs, as will be discussed the results sections for those specific experiments, this hysteresis was as large as 20%. Replicate solubility isotherms were collected for several gas/IL combinations during this work, as will be pointed out in the subsequent results sections. The standard deviation between repeated experiments was typically within the error seen due to uncertainty in equilibration, therefore the difference between absorption and desorption isotherms was taken to be the experimental error. Any exceptions to this scenario will be pointed out in that specific results section.

The errors associated with properties derived from the solubility isotherms, such as Henry’s constants and enthalpies and entropies of absorptions, result from both uncertainty in achieving equilibrium and from fitting a curve to the data (especially for the lower solubility gases). To estimate the error bars for the linear fits of the data, a method was used in which lines were drawn so the normalized deviation of the data points (including both absorption and desorption data) outside this range was less than 10%. A detailed example of these error calculations are given in Appendix B.

For the higher solubility data, where good fits to the data were seen, the difference between the fit to the absorption data and the desorption data was taken to be the error.

The uncertainty in the IL density measurements can also affect the uncertainty in the solubility measurements. The reported uncertainty for the densities used in this work were all about 0.5% or less, the effects of which yield Henry’s constants within the range of the error due to deviation from equilibrium and from the linear fit. But if the uncertainty in density is greater than 0.5%, there is a significant increase in the

43 uncertainty for the gases with Henry’s constants greater than 2000 bar. For example, if the uncertainty in the density is 1%, then the uncertainty for a low solubility gas

Henry’s constant such as oxygen is about 72%, whereas the uncertainty is only about

15% for the more soluble methane. Therefore, high quality gravimetric solubility measurements of sparingly soluble gases require very accurate IL density data.

3.3 Static High-Pressure Apparatus

The apparatus used for the high pressure CO2 solubilities in dry and wet ionic liquids was originally designed in 1961.118 A detailed description of the apparatus, most recent modifications, and operating procedure can be found elsewhere.119

3.3.1 Apparatus Details

The apparatus, a schematic of which is shown in Figure 3.7, can be divided into two major sections: the pump-side (everything to the left of valve 1 in Figure 3.7) and the cell-side (everything to the right of valve 1).

On the pump side, a 100 mL positive displacement pump (Model 2200, Ruska,

Inc.) displaces mercury into a pressure vessel. This volume displacement, which has an accuracy of + 0.002 mL, compresses the gas in the vessel to a certain pressure.

The pressure is measured by a Heise-Bourdon tube gauge (P1 in Figure 3.7), which has a range of 0 – 3000 psi and an accuracy of + 0.8 bar. The temperature of the mercury in the pump is measured by a RTD thermocouple (T0). With the exception of the displacement pump, an air bath controls the temperature for the remainder of the pump-side components. The air bath is coarsely heated with a coiled resistance

44 heater (Rex Rheostat, Inc.) controlled by a Variac (Model 3PN1010). A 300 W flood lamp is used for fine control of the air bath temperature. The temperature is maintained at 80 oC by a Omega temperature controller (Model BS5001J1). The temperature of the air bath and the vessel are measured using Type T, J, and K thermocouples, shown in Figure 3.7 by T8 (type J), T3 (type K), T4 (type T), and T9

(type T). T3 and T4 are inserted into thermocouple wells in the pressure vessel and

T9 measures the surface temperature.

Hg 7 Reservoir Vent P1

T0 T8 Pump T2 T6 T5 D C 4 2 1 T7 E H G Gas T P2 T4 F B Pressure T9 Vessel Gas T3 3 Cell A Fill Gas Hg 5 Liquid 6 Water Bath

Air Bath

Figure 3.7 Schematic of static high pressure apparatus

Valves 5 and 6 can be used to drain the mercury from just the pump (valve 6 open and valve 5 closed) or the pump and vessel (both valves 5 and 6 open). Valves A through E are remnants from earlier modifications and are no longer used (isolated

45 from the system by closing valve 4). The gas in the system can be replenished directly by connecting a gas supply source to the line at valve 3. Valves that remain closed during the course of a typical experiment are shown as solid symbols in Figure

3.7, whereas valves that remain open are shown using open symbols.

Valve 1 allows pressure to be introduced to the cell side of the apparatus from the pump side. The pressure on the cell side is measured using a Heise electronic pressure transducer (Model 901A, 3000 psi) readable to 0.1 psi with an accuracy of +

2 psi. The lines between valve 1 and the cell (including the line between valve 7 and the pressure transducer) are heated to 75 oC using heating tape (Thermolyne, Inc.).

Temperatures along the lines are monitored by T2, a RTD thermocouple, and T5, T6, and T7, which are Type K thermocouples. The sample cell is submerged in a stirred, isothermal water bath. The water bath is heated by a quartz immersion heater (P/N

11-463-15, Fisher Scientific, Inc.), which is controlled by a Sargent-Welch temperature controller (Model T), and the temperature is measured by a RTD thermocouple (T in Figure 3.7).

The sample cell was made from a single crystal sapphire (Rubikon, Inc.) and has a pressure rating of 5000 psi. The cell’s dimensions are 3/8” OD and 4” long. A

TeflonTM coated magnetic stir-bar placed within the cell in conjunction with an external magnet is used to stir the gas and liquid phases inside the cell. The volume of the liquid in the cell is determined by measuring the height of the liquid with a cathetometer (Garertner Scientific Corp.). This height correlates to a volume based on a volumetric calibration of the cell using a high-precision buret (+ 0.02 mL) with n-tetradecane.119

46 The solubility of gas in the liquid can be calculated by knowing the moles of gas added to the cell side from the pump side and the moles of gas remaining in the cell- side lines and cell head space. The moles of gas dissolved in the liquid is the difference between the moles of gases added to the sample side and the moles of gas remaining in the gas phase on the sample side (in the lines and cell above the liquid level). The number of moles of gas added to the cell side from the pump side is calculated from an equation of state knowing the temperature and the pressure of the gas on the pump side and volume of the gas added based on the volume change of the displacement pump. The number of moles of gas remaining on the sample side is also calculated from an equation of state knowing the pressure, temperature and volume of the gas. The volume of the lines between valve 1 and the cell (including the line between valve 7 and the pressure transducer) is determined by a calibration using nitrogen gas (99.98%, Mittler Supply Co.). The volume of the gas in the cell above the liquid is calculated by subtracting the measured volume of the liquid from the total volume of the cell. These calculations assume no moles of the solvent are present in the gas phase, which is a good assumption for the nonvolatile ILs used in this work. The gas phase was periodically bubbled through ethanol and analyzed by

UV-vis spectroscopy to confirm no measurable IL is present.

The sources of error in these experiments result from the errors in measuring the pressures, temperatures, and volumes. The error in the volume displaced by the pump is 0.01 mL, the volume of the lines is 0.01 mL, and the volume of the cell is 0.05 mL.

The error in measuring the height of the liquid in the cell is 0.005 cm. The error in the temperature of the water bath is 0.05 oC and 0.1 oC for the other thermocouples

47 (on the lines and the pressurized vessel). The error in the pressure readings is 0.07 bar for both the pump and cell sides. The final error in the gas solubility is determined using basic error propagation. A detailed description of the error analysis for these calculations can be found elsewhere.119

3.3.2 Dry versus water-saturated experiments

This high pressure apparatus was used to measure the CO2 solubility in dry

o [bmim][Tf2N] and water-saturated [bmim][Tf2N] at 25 C. The dry IL contained

<500 ppm H2O and the water-saturated IL contained 1.58 + 0.3 wt% H2O, both measured by Karl-Fischer titration (AQUASTAR V-200, EM Science). A highly- accurate equation of state for pure CO2 as developed by Wagner and coworkers was used for the gas solubility calculations.132

3.4 H2O / IL Liquid-Liquid Equilibrium Measurements

The mutual solubilities of liquid water with a series of three ionic liquids,

[bmim][PF6], [C8mim][PF6], and [C8mim][BF4], were conducted as a supplement to the gas solubility measurements. The use of activated carbon to remove [bmim][PF6] from the aqueous phase was also investigated.

3.4.1 LLE setup

For the liquid-liquid equilibrium measurements, several milliliters of IL and water were vigorously mixed in a test tube sealed with parafilm. For all three of the ILs tested, the phases were allowed to separate for 1 to 2 h after cessation of the stirring

48 in order to ensure clean separation of the phases. Ambient conditions were 22 + 1 °C and 0.98 + 0.03 bar. For measurements at temperatures higher than ambient temperature, the sample vials were immersed in a water bath that was controlled within 1 °C.

3.4.2 Analysis of liquid phases

Samples from each phase were drawn using a syringe. The IL content in the water-rich phase was analyzed using UV-vis spectroscopy (Cary 3, Varian), which has a sensitivity of + 0.01 for the absorbance and + 0.2 nm for the wavelength. The maximum absorbance for each of the ILs, due to the imidazolium ring, is at 211 nm.

Calibrations were performed for each of the ILs in water; the resulting values of εmax

3 -1 -1 3 -1 -1 are 4.80 + 0.1 × 10 M cm for [bmim][PF6], 4.19 + 0.30 × 10 M cm for

3 -1 -1 [C8mim][PF6], and 4.17 + 0.29 × 10 M cm for [C8mim][BF4]. These calibration curves are shown in Appendix C.

The water content of the IL-rich phase was determined using a Karl Fischer titrator (AQUASTAR V-200, EM Science). A sample size of 0.5 g was used for each analysis of [bmim][PF6] and 0.3 g for [C8mim][PF6] and [C8mim][BF4]. These sample sizes were found to be large enough to give reproducible results to about + 0.2 wt%. Both phases were analyzed after 24 h of stirring and again after 48 h. No noticeable difference in the results confirms that equilibrium was achieved. Multiple measurements were made to ensure reproducibility. Care had to be taken with the samples at elevated temperatures. The aqueous phase samples were diluted with additional water for analysis, so they were not a problem. However, the IL-rich phase

49 samples had to be analyzed (by Karl Fischer titration) immediately upon removal from the equilibration vial. Otherwise, cooling would result in a phase split in the syringe and erroneous results.

The errors reported for both the IL in the aqueous phase and the H2O in the IL phase were found based on the standard deviation of the replicates (at least 3 per sample).

3.5 Activated Carbon Measurements

A solution of [bmim][PF6] in water was placed in vials with various amounts of activated carbon (AC) ranging from 0.002 to 0.12 g AC/mL solution. The activated carbon was Norit RO 0.8 pellets from Aldrich. Solutions were mixed by rotating the vials in a water bath at ambient conditions (22 + 1 °C) for 2 days and also for 2 weeks to ensure that equilibrium was achieved. UV-vis spectroscopy was used to detect the cation content of the aqueous solution. In order to confirm that the anion was also being removed from the solution, the Inductively Coupled Plasma Optically Emitting

Spectrometer (ICP-OES) was used to detect the phosphorous of the anion remaining in the aqueous solution. The ICP-OES has a phosphorous detection limit of 20 ppb.

Scans were collected at two different wavelengths to detect the phosphorous: 213.617 nm, and 214.914 nm. A phosphorous standard (Spex CertiPrep) containing 1002 ppm phosphorous in water was diluted to get four solutions, ranging in concentration from

3.98 ppm to 89.30 ppm phosphorous. These solutions were uses to develop calibration curve for detecting the phosphorous concentration in the IL solution, as given in Equations 3.3 and 3.4:

50 213.617 nm: Conc (ppm P) = (2.17 × 10-4) × (Peak Intensity) + 0.402 (3.3)

214.914 nm: Conc (ppm P) = (4.96 × 10-4) × (Peak Intensity) + 0.778 (3.4)

Three replicates of each concentration at both wavelengths were measured; the standard deviation for each calibration is less than 3%. These calibration curves are shown in Appendix A. Three replicates were also completed for the ionic liquid sample at both wavelengths; the deviation between those concentrations was less than

5%, which was taken to be the error in the measurement.

3.6 Gas Separations Measurements

Experiments to determine if ionic liquids are capable of separating gas mixtures were done using two experimental setups: a supported ionic liquid membrane apparatus and a conventional absorber setup.112 Experiments were done using the ionic liquid [bmim][PF6] and using three gas mixtures: 10 mol% CO2 in N2, 10 mol%

CO2 in CH4, and a 50 mol% mixture of C2H4 and C2H6.

3.6.1 Analysis of gas composition

Gas compositions in the feed and effluent streams of both experimental setups were measured by either a Varian 3400 CX Gas Chromatograph or a Varian 3800 Gas

Chromatograph, both equipped with thermal conductivity detectors. Retention times for the specific gases were determined using pure gases and then confirmed with the premixed gas mixtures. The GC columns used were either an Alltech HayeSep Q

80/100 (1.8 m × 0.32 cm × SS) column or an Alltech HayeSep D 100/120 (6.1 m ×

0.32 cm × Ni) column. The HayeSep Q column is capable of separating CO2, air,

51 CH4, C2H6, and C2H4. The HayeSep D column is capable of separating those same gases, but can also separate air into N2 and O2. Slightly differing GC methods for analysis were used throughout the experiments, but in each situation, samples of the feed gas were also analyzed to confirm the retention times of the gases. For example, in one method for the HayeSep Q column, the column oven temperature was 50 oC, the detector and injection port temperatures were 150 oC, and the filament temperature was 145 oC. The helium carrier gas pressure and flow rate in the column were 15 psi and 20 mL/min, respectively. The reference flow rate through the detector was 30 mL/min. In this method, the retention times were 0.90 min for air

(N2), 1.3 min for CH4, 2.4 min for CO2, 4.2 min for C2H4 and 5.9 min for C2H6.

Similar retention times were observed for the various other methods used.

3.6.2 Supported ionic liquid membranes

3.6.2.1 Membrane apparatus

The separation experiments using supported-ionic liquids were conducted on the apparatus shown in Figure 3.8. In this apparatus, three membranes were placed in parallel, shown by the shaded rectangles in Figure 3.8. Two five-port valves (SS-

43ZF2, Swagelock), labeled as V-1 and V-2 in Figure 3.8, allow for the apparatus to be used in several different configurations. The valve V-1 toggles between a feed gas line, a helium line, and a vacuum line. The valve V-2 toggles between exposing the permeate side to the atmosphere, allowing an opening between the permeate and the feed sides, or isolating the permeate side from both the atmosphere and the feed side.

During the permeation experiments, V-2 is always in this last, isolated position. The

52 ability to open the permeate side to the feed side lines is used in procedures for preparing the system for an experiment. Changing V-2 to expose the permeate side to the atmosphere is necessary for depressurizing the system.

The pressure on the feed side was controlled using a line regulator, LR-1 (2051021-

01-000, 0 – 30 psi, Concoa). A metering valve (15-11AF1, HiP, Inc.), MV-1, allows finer control when pressurizing the system to avoid a pressure-spike that might result in IL “blow-out”. The permeate side could be pressurized with helium independently of the feed side using line regulator LR-2 (2051021-01-000, 0 – 30 psi, Concoa).

V-1 Vacuum

He He Gas Mixture

P F P

Carrier P MV-1 LR-1 Gas

LR-2 (Carrier Gas) (To GC Column) V-2 SV-A 2 3 To GC 1 4 Column 6 5 Vent Permeate SV-B 1 HIP-1 2 6 Sample Sample Loop 3 5 4 HIP-5 HIP-3 Sample Loop Membranes HIP-7 Vent To Measure Feed HIP-2 Feed Flowrate Sample HIP-6 and Vent

From Gas Cylinder HIP-4 for Calibration Measurements Blocked

Figure 3.8 Schematic of the supported liquid membrane apparatus

53 Samples are injected into the gas chromatograph using one of two six-port sampling valves, SV-A (Model ADT0549, VICI) and SV-B (Model ABV0560,

VICI). These two valves are situated in series and allow for samples to be collected from either the permeate side by SV-A or the feed side by SV-B. The sample loop is

102.1 µL on SV-A and 250 µL on SV-B. Valves HIP 1 through 7 are taper seal valves from High Pressure Equipment (HiP), Inc. (model 15-11AF1).

3.6.2.2 Membrane preparation

Both stainless steel and ceramic membranes were considered as the support for the membranes. The stainless steel membranes from Mott Corporation were tried, both before and after sintering, but due to their irregular pore size distributions were abandoned. Ceramic Anopore® membranes (Anodisc 25, Whatman) were used with pore sizes of 0.2 µm and 0.02 µm. These membranes have a diameter of 25 mm and a thickness of 0.12 mm. To determine the maximum pressure-drop (P) possible across the membrane that would not “blow-out” the ionic liquid, equation 3.1 was used:

4 ⋅σ ⋅ cos(α ) P = g ⋅ ρ ⋅ h + (3.1) D where σ is the surface tension, g is the gravitational constant, ρ is the density of the ionic liquid, h is the height of the liquid column in the pore (assumed to be equivalent to the membrane thickness), D is the pore diameter, and α is the contact angle between the ionic liquid and the surface of the pore. A surface tension of 0.046 kg/s2 was assumed for the IL.138 The contact angle for ILs is unknown, but the calculations were repeated for contact angles ranging from 40o to 89o. A contact angle of 90o

54 indicates the liquid meniscus is parallel to the surface of the membrane surface.

Based on the results of these calculations (Table 3.3), the clear choice of pore size is0.02 µm as it allows for stable membranes with the largest pressure range. Based on problems with “blow-out” seen while trying to use membranes with 0.2 µm pores and pressure drops of approximately 2 to 3 psig, it is assumed that the IL/ceramic contact angle is fairly close to 90o (i.e. the IL meniscus is relatively horizontal).

TABLE 3.3

PRESSURE DROP CALCULATION TO “BLOW” LIQUIDS OUT OF VARIOUS

SIZE PORES

Pore Diameter (µm) 2 0.5 0.2 0.02

Contact Angle Pressure Drop (psig) 89 0.2 0.9 2.3 23.3 88 0.5 1.9 4.7 46.6 87 0.7 2.8 7.0 69.8 85 1.2 4.7 11.6 116.3 80 2.3 9.3 23.2 231.6 75 3.5 13.8 34.5 345.3 70 4.6 18.3 45.6 456.3 60 6.7 26.7 66.7 667.0 50 8.6 34.3 85.7 857.5 40 10.2 40.9 102.2 1021.9

The membrane pores were filled with [bmim][PF6] by coating the membrane with the ionic liquid. The ceramic membrane turns from white to translucent as the IL wets the material. The coated membranes were allowed to sit for at least 24 hours in an inert atmosphere to allow the IL time to fully fill the pores. The excess IL was

55 gently wiped off the surface of the membranes with a Kimwipe. The membranes were placed in 25 mm Swin-LokTM filter holders (420200, Corning), sealed with a silicone o-ring, and inserted in the apparatus shown in Figure 3.5. To confirm the pores were completely filled, the feed side of membrane apparatus and was pressurized with helium gas. If no flowrate was measured on the permeate side

(detection limit of 0.05 mL/min), the pores were considered to be filled.

3.6.2.3 Operating procedure

Prior to experimental runs, the system was evacuated under vacuum capable of pulling at least 30 mmHg for at least 24 hours to remove water and dissolved gases from the ionic liquid and to remove any gases in the system. To pull vacuum on the entire system, V-1 is turned to the vacuum line and V-2 is turned to open the permeate side to the feed. The line regulator LR-1, and valves MV-1, HIP-1, HIP-2, and HIP-7 are all opened, whereas LR-2, and valves HIP-3, HIP-4, HIP-5, are HIP-6 are closed. This setup allows equal vacuum pressure to be pulled on both sides of the membranes. Following the process of vacuuming the system, the system is flushed with helium. Flushing is accomplished by turning V-1 to the helium line. V-2 is left open to both feed and permeate sides. LR-1 is adjusted to set the pressure (between 2 and 10 psig) and MV-1, HIP-1, HIP-2, and HIP-7 are opened. HIP-3 cracked to control helium flow rate out (between 5 mL/min and 75 mL/min). LR-2, HIP-4, HIP-

5, and HIP-6 all remain closed. Before starting an experiment, the feed and permeate sides are isolated (using V2 and closing HIP-7). The permeate side is pressurized

56 with 2 bar helium and the helium on the feed side is slowly released to atmospheric pressure before pressurizing with the feed gas.

During an experiment, V-1 is turned to the gas mixture line and V-2 is closed to isolate the permeate side. The pressure on the feed side is set using LR-1 (between 2 and 10 psig). MV-1 is opened slowly, to prevent the system from pressurizing too quickly and risking IL “blow-out”. HIP-2 is cracked to control flow rate. LR-2, HIP-

1, HIP-3, HIP-4, HIP-5, HIP-6, HIP-7 all remain closed. Samples from the permeate side were injected into the GC using SV-A every 10 to 30 minutes.

3.6.3 Absorber

The absorber was a 2.5 cm diameter stainless steel column packed with borosilicate glass beads (0.48 cm diameter).112 Sufficient ionic liquid was added to

o 12 coat the beads in excess. [bmim][PF6] is relatively viscous (371 cP at 20 C), so there were no problems with the liquid separating from the beads. The gas mixture was fed at the base of the column. The pressure was measured on the inlet side and the effluent flow rate was measured. The ionic liquid was regenerated (i.e. absorbed gases removed) by pulling a vacuum for at least 12 hours.

As previously discussed, the effluent gas composition was measured by gas chromatography. Samples of the effluent were collected approximately every 10 to

20 minutes and injected into the GC. The ratio of the two gases in the effluent stream was calculated from the ratio of the peak areas for each of the gases.

57

CHAPTER 4

RESULTS - GAS SOLUBILITIES

This chapter presents gas and vapor solubilities in a variety of ionic liquids. The first section focuses on the solubility of carbon dioxide in several ionic liquids and how the structure of the cation and anion affects the CO2 solubility, Henry’s constants, and enthalpies and entropies. Section 4.2 discusses the solubility of a range of gases in three different ionic liquids, [bmim][PF6], [bmim][BF4], and

[bmim][Tf2N] and provides insight on how the different properties of the various gases and the IL anions affect the solubility, Henry’s constants, and enthalpies and entropies. Finally, Section 4.3 provides results for a few additional gas/IL systems that were investigated.

4.1 Solubility of Carbon Dioxide

Previous investigations in our laboratories had shown the carbon dioxide is highly

61, 62 soluble in imidazolium-based ionic liquids and supercritical CO2 can be used to extract solutes from the ILs.53, 54, 62 In the present work, carbon dioxide was dissolved in a variety of ionic liquids with different cations and anions to try to elucidate the factors governing the high solubility in these ILs. The 1-n-butyl-3- methylimidazolium cation was used with three different anions (hexafluorophosphate, tetrafluoroborate, and bis-trifluorosulfonylimide) to look how the anion affects the

58 CO2 solubility. Three pairs of ionic liquids were studied to see how replacing the hydrogen with a methyl group at the second position on the imidazolium ring changes the solubility of CO2. Finally, different cations, such as tetraalkylammoniums and a pyrrolidinium, with the bis-trifluorosulfonylimide anion were studied to investigate the role of cation in determining the CO2 solubility.

4.1.1 Effects of anion with [bmim] cation

The effect changing anions has on the CO2 solubility was investigated by looking at three different anions: [PF6], [BF4], and [Tf2N], all with the 1-butyl-3-methyl imidazolium cation.

7 4.1.1.1 [bmim][PF6]

Three isotherms were collected for CO2 in [bmim][PF6] using the Sachem sample, as shown in Figure 4.1. The measurements were made using the stainless steel bucket and a 90 minute equilibration time per point. Tables of all the raw data can be found in Appendix D.

59 0.4 10 oC 25 oC 0.3 50 oC

0.2

Mole Fraction 0.1

0.0 02468101214 Pressure (bar)

o o o Figure 4.1 CO2 in [bmim][PF6] at 10 C, 25 C, and 50 C

8 4.1.1.2 [bmim][BF4]

Three isotherms were collected for CO2 in [bmim][BF4] using the sample from

Professor Tom Welton’s group, as shown by the solid symbols in Figure 4.2. The measurements were made using the stainless steel bucket and a 90 minute equilibration time per point for the 10 oC isotherm and 180 minutes per point for the

25 oC and 50 oC isotherms. Although this sample was kept in an inert atmosphere, it was approximately one year old at the time of the experiments and therefore there was some concern that degradation products may have formed.139 Experiments were repeated using the fresh sample synthesized by Jacob M. Crosthwaite in our laboratory, as shown by the open symbols in Figure 4.2. These measurements were made using quartz bucket 4 with a 120 minute equilibration time. Multiple measurements were collected for the 25 oC and 50 oC isotherms using quartz bucket 1 with a 90 minute equilibration time and for 25 oC using quartz bucket 4 with a 180 minute equilibration time. Tables of all the raw data can be found in Appendix D. In all cases, approximately 120 minutes would have been sufficient for equilibrium.

60 0.4 o 10 C (TW) 50 oC (TW) o 10 C (JMC) 50 oC (JMC) o 0.3 25 C (TW) 50 oC (JMC) 25 oC (JMC) o 0.2 25 C (JMC) 25 oC (JMC)

Mole Fraction 0.1

0.0 02468101214 Pressure (bar)

o o o Figure 4.2 CO2 in [bmim][BF4] at 10 C, 25 C, and 50 C

Any differences between the two different samples were within the scatter seen with the multiple runs with the same sample (between 1 % and 3% difference). Therefore, it was assumed that no degradation products that could affect CO2 solubility were present.

140 4.1.1.3 [bmim][Tf2N]

Three isotherms were collected for CO2 in [bmim][Tf2N] using the Covalent sample, as shown in Figure 4.3. The measurements were made using quartz bucket 1 and a 90 minute equilibration time per point. This equilibration time was long enough for both 25 oC and 50 oC. However, a slight hysteresis was seen between the absorption and desorption isotherms at 10 oC, which is reflected by the larger uncertainties in the Henry’s constants as will be reported in the following section.

Tables of all the raw data can be found in Appendix D.

61 0.4 10 oC 25 oC 0.3 50 oC tion c 0.2 Fra

Mole 0.1

0.0 02468101214 Pressure (bar) o o o Figure 4.3 CO2 in [bmim][Tf2N] at 10 C, 25 C, and 50 C

4.1.1.4 Comparison between ionic liquids

The 25 oC isotherms for the three ionic liquids are shown in Figure 4.4. The IL with the [Tf2N] anion has a considerably higher affinity for CO2 than either of the other two ILs. The [bmim][BF4] and [bmim][PF6] have basically the same solubility, although the [bmim][PF6] appears more soluble at higher pressures. These same trends are also seen at the other temperatures, as is apparent by comparing Figures 4.1 through 4.3. The solubility decreases as temperature increases in all three cases, as is typically expected with gas solubilities in liquids. The curves exhibit a nonlinear trend as the CO2 pressure is increased; the curves begin to flatten out, indicating that the IL is beginning to approach its maximum, pressure-independent capacity for CO2.

Other researchers have observed that the CO2 solubility approaches a maximum between 70 and 90 mol% CO2 in the IL and the system still remains two phases, even up to pressures of 3100 bar.61, 69 This behavior is unusual when compared to other

62 0.35 [bmim][Tf N] 0.30 2 [bmim][PF6] 0.25 [bmim][BF4] 0.20 0.15 0.10 Mole Fraction 0.05 0.00 02468101214

Pressure (bar) o Figure 4.4 CO2 in [bmim][PF6], [bmim][BF4], and [bmim][Tf2N] at 25 C

organic liquid-CO2 mixtures, which typically reach a mixture critical point at a certain pressure and become one phase.61, 69

The solubilities of CO2 in [bmim][PF6] measured in this work are in qualitative agreement with previously published results from our laboratory at higher pressures, which were found using the static high-pressure apparatus technique.61 Both sets of data at 50 °C are shown in Figure 4.5. It should be noted that these experiments at high pressures were conducted before it was general practice to test the ILs for impurities. The sample used was colored and contained 0.15 wt% water and probably contained other impurities, such as degradation products, as well. Subsequent measurements in our laboratory of CO2 solubilities at high pressures in cleaned

[bmim][PF6], [bmim][BF4], and [bmim][Tf2N] compare remarkably well with the low pressure data presented in this work. A comparison of the low pressure and high pressure data for CO2 in [bmim][Tf2N] is shown in the following chapter (in Figure

5.4).

63 0.8 Blanchard et al., 2001 Anthony et al., 2002 0.6 on i

0.4

Mole Fract 0.2

0.0 0 20406080100

Pressure (bar)

Figure 4.5 Comparison of CO2 in [bmim][PF6] at low and high pressures

4.1.1.5 Henry’s constants

As discussed in Chapter 2 (Section 2.2.1), a Henry’s constant is the linear relationship between gas concentration and pressure. Therefore, Henry’s constants can be found by calculating the slope of the data at low solute concentrations. Since the CO2 isotherms are not linear over the entire pressure range, the Henry’s constants were found by fitting a second order polynomial to the data and calculating the limiting slope as the pressure (or solubility) approaches zero. These constants for CO2 in the three ionic liquids at the three temperatures are listed in Table 4.1. The reported error is based on the difference between constants calculated for the absorption and desorption isotherms. The reproducibility between different samples of the same IL is approximately 1 to 3%; typically this deviation is within the error

o bars determined from the absorption/desorption hysteresis. For [bmim][BF4] at 25 C and 50 oC, the standard deviation between samples was slightly larger than the deviation between absorption and desorption Henry’s constants. Therefore, the larger

64 TABLE 4.1

HENRY’S CONSTANTS AND ENTHALPIES AND ENTROPIES OF

ABSORPTION FOR CO2 IN [bmim][PF6], [bmim][BF4], AND [bmim][Tf2N]

Ionic Liquid H (bar) ∆h (kJ/mol) ∆s (J/mol K) 10 oC 25 oC 50 oC [bmim][PF6] 38.7 + 0.4 53.4 + 0.3 81.3 + 0.5 -16.1 + 2.2 -53.2 + 6.9 [bmim][BF4] 40.8 + 2.7 56.5 + 1.4 88.9 + 3.2 -15.9 + 1.3 -52.4 + 4.3 [bmim][Tf2N] 27.1 + 5.8 33.0 + 1.4 49.1 + 1.2 -11.4 + 4.0 -37.6 + 13

of the two deviations was reported as the experimental error. The 10 oC constants are smaller than those at the other temperatures for all three systems, illustrating the higher solubility at the lower temperature. The small differences between the

Henry’s constants for [bmim][PF6] and [bmim][BF4] again emphasize that a [PF6] versus [BF4] anion has little effect on the CO2 solubility, whereas the significantly smaller Henry’s constants for [bmim][Tf2N] show that the [Tf2N] anion can dramatically increase the CO2 solubility. Yet, as will be emphasized in Section 4.2, all three ionic liquids exhibit a relatively high affinity for CO2 when compared to other gases.

Subsequent to the work presented here,7 Maurer and coworkers also reported

67 solubility measurements for CO2 in [bmim][PF6]. They use a different definition for Henry’s constant ( k (T ) ), which is given below: H,CO2

lim  f (T, p) k (T ) = CO2 (3.1) H,CO2 s  o  p → P [bmim][PF6 ] = 0 m m  CO2 

65 s where p is the pressure, P [bmim][PF6 ] is the vapor pressure of [bmim][PF6]

(approximately zero), f (T, p) is the fugacity of the CO2 at a specific temperature CO2

o 67 and pressure, m is the mass of the CO2, and m is 1 mol/kg. They report values CO2 of 1.20 MPa at 20 oC, 1.89 MPa at 40 oC, and 2.70 MPa at 60 oC.67 Converting the

Henry’s constants reported in Table 4.1 to the form used by Maurer and coworkers yields k (T ) values of 1.07 MPa at 10 oC, 1.49 MPa at 25 oC, and 2.28 MPa at 50 H,CO2 oC. Both sets of Henry’s constants are fairly consistent with each other.

66 Hussen-Borg et al. have recently reported CO2 solubilities in [bmim][BF4]. At

30 oC, their Henry’s constants range between 55 and 64 bar.66 These are fairly consistent with the value reported here at 25 oC (56.5 + 1.4 bar). At 50 oC, their

Henry’s constants range between 71 and 79 bar,66 which are somewhat lower than the 88.9 + 3.2 bar reported here (i.e. they measured a slightly higher solubility). One possible explanation for this difference might be due to impurities in the ionic liquid samples; Hussen-Borg et al. report an overall purity of 97 mol% with a chloride content of 0.01 wt% and a water content of 700 + 40 ppm.

4.1.1.6 Enthalpies and entropies of absorption

Also listed in Table 4.1 are the enthalpies and entropies of absorption for CO2 in the three ILs. As explained in Chapter 2, information about the strength of interaction between the IL and gas is provided by the enthalpy, while information about the degree of ordering that takes place upon dissolution of the gas is given by the entropy.

66 All three ILs exhibit significant interactions and ordering upon absorption of CO2; however, the CO2 interactions with [bmim][Tf2N] appear to be slightly stronger.

Maurer and coworkers report values of -17.24 kJ/mol for the enthalpy and -79.5

67 J/mol K as the entropy of absorption of CO2 in [bmim][PF6]. Hussen-Borg et al. found the enthalpy and entropy of CO2 absorption into [bmim][BF4] to range between

-6.3 to -10.2 kJ/mol and -55.5 to -67.8 J/mol K, respectively.66 These values are fairly consistent with those reported here.

4.1.2 Effect of methyl group versus hydrogen on cation95

The hydrogen at the 2-postion on the imidazolium ring has been found to be the

most acidic hydrogen on the ring.127, 141, 142

In this work, the acidic hydrogen (see Figure - X 4.6) is replaced with a methyl group for + N N three different ionic liquids: [bmmim][PF6],

R CH3 [bmmim][BF4], and [emmim][Tf2N], to see

H or CH3 how the hydrogen versus methyl group on Figure 4.6 Structure of imidazolium ring with the ring affects the solubility of carbon hydrogen or methyl group

at the 2-carbon position dioxide. The CO2 solubility in

[emim][Tf2N] is also reported for

comparison.

67 4.1.2.1 Solubility isotherms

The solubility isotherms at 10 oC, 25 oC and 50 oC for each of the six ionic liquids are shown in Figures 4.7, 4.8 and 4.9, respectively. Both absorption and desorption data have been plotted. The CO2 solubility in the Covalent samples of [emim][Tf2N] and [emmim][Tf2N] was measured using the stainless steel bucket and allowed 90 minutes to equilibrate. The 25 oC experiments were also measured in samples of

[emim][Tf2N] and [emmim][Tf2N] from Professor Peter Wasserscheid’s laboratory using the stainless steel bucket. Equilibration times of 120 minutes for [emim][Tf2N] and 90 minutes for [emmim][Tf2N] were used, although 90 minutes would have been sufficient for both. These isotherms are plotted as the inverted triangles in Figure 4.8.

There was no measurable differences between the two samples. The 25 oC experiment was repeated for [emim][Tf2N] using the flowing mode option on the apparatus, rather than the static mode as used in all the other experiments. No differences were observed between the two modes (see Appendix D for data and

Appendix E plot). The experiments using [bmmim][PF6] and [bmmim][BF4] samples from Professor Tom Welton’s group were conducted using the stainless steel bucket and allowed 180 minutes for equilibration. As described in Section 4.1.1.2 for

[bmim][BF4], these samples were also kept in an inert atmosphere but not used for approximately one year. Due to concerns about degradation in [PF6] and [BF4]

139 ILs, experiments were repeated using a cleaned-up sample of [bmmim][PF6] from

Solvent Innovation using quartz bucket 4 and given 120 minutes for equilibration.

No differences were observed in the CO2 solubility (same with [bmim][BF4]), so it was assumed that no degradation products had formed that would influence the CO2

68 0.30

0.25

0.20

0.15

0.10 Mole Fraction 0.05

0.00 02468101214

Pressure (bar)

Figure 4.7 Solubility of CO2 in [emim][Tf2N] - „, [emmim][Tf2N] - , [bmim][PF6] o - z, [bmmim][PF6] - {, [bmim][BF4] - S, and [bmmim][BF4] - U at 10 C

0.30

0.25

0.20

0.15

0.10 Mole Fraction 0.05

0.00 02468101214 Pressure (bar)

Figure 4.8 Solubility of CO2 in [emim][Tf2N] - „, [emmim][Tf2N] - , [bmim][PF6] o - z, [bmmim][PF6] - {, [bmim][BF4] - S, and [bmmim][BF4] - U at 25 C

69 0.30

0.25

0.20

0.15

0.10 Mole Fraction 0.05

0.00 02468101214

Pressure (bar)

Figure 4.9 Solubility of CO2 in [emim][Tf2N] - „, [emmim][Tf2N] - , [bmim][PF6] o - z, [bmmim][PF6] - {, [bmim][BF4] - S, and [bmmim][BF4] - U at 50 C

solubility for each of the ILs (including [bmmim][BF4], which was not subjected to a replicate absorption experiment). At 10 oC, there is slight hysteresis between the absorption and desorption for [bmmim][PF6] and [bmmim][BF4], which is reflected in larger uncertainties in the Henry’s law constants shown in Table 4.2. It should be noted that at both 10 oC and 25 oC, some of the ionic liquids are subcooled liquids.18

Visual observations before and after the gas solubility measurements, however, indicate that the samples remained liquid on experimental time scales. Tables of all the raw data can be found in Appendix D.

In the figures, the ionic liquids with a hydrogen attached to the 2-carbon are shown using filled symbols, while the ILs with a methyl group substituted in the 2- position are shown using open symbols. At all temperatures, the ILs with the [Tf2N] anion show the highest CO2 solubility, whereas there is little difference between the

CO2 solubilities in the [BF4] versus [PF6] based ILs. The effect temperature has on

70 the solubility difference between the methyl-substituted and hydrogen-substituted ILs suggests that this substitution induces some change in the energetic interactions

o between CO2 and the cation. At 10 C (Figure 4.7), there is some decreased solubility for the methyl-substituted IL relative to the hydrogen-substituted IL in each pair, particularly at higher pressures. As the temperature is increased, the discrepancy

o between the CO2 solubility in each of the three pairs of ILs decreases so at 50 C, there is very little difference between the two ILs (Figure 4.9). However, this trend is less dramatic with the more CO2-philic [emim][Tf2N] and [emmim][Tf2N] compounds. This suggests that the interactions governing the higher solubility of

CO2 in the [Tf2N] ILs are not influenced as strongly by the presence of a hydrogen or methyl group on the C2 carbon relative to the influence of the anion.

4.1.2.2 Henry’s constants

Table 4.2 lists the Henry’s constants (H) in bar for the six ionic liquids, each at 10 oC, 25 oC, and 50 oC. For all three pairs, the presence of the methyl group slightly increases the Henry’s constants (i.e. decreases the CO2 solubility), but the overall effect is minor. This indicates that the presence of the hydrogen at the 2-position only has a small impact on the CO2 solubility. Therefore, other factors are responsible for the high CO2 solubility observed in these ILs, as will be elaborated upon further

Section 4.2.5.

71 TABLE 4.2

HENRY’S CONSTANTS AND ENTHALPIES AND ENTROPIES OF

ABSORPTION FOR CO2 IN [bmim][PF6], [bmmim][PF6], [bmim][BF4],

[bmmim][BF4], [emim][Tf2N], AND [emmim][Tf2N]

Ionic Liquid H (bar) ∆h (kJ/mol) ∆s (J/mol K) 10 oC 25 oC 50 oC [bmim][PF6] 38.7 + 0.4 53.4 + 0.3 81.3 + 0.5 -16.1 + 2.2 -53.2 + 6.9 [bmmim][PF6] 47.3 + 7.5 61.8 + 2.1 88.5 + 1.8 -13.0 + 1.3 -42.8 + 9.8 [bmim][BF4] 40.8 + 2.7 56.5 + 1.4 88.9 + 3.2 -15.9 + 1.3 -52.4 + 4.3 [bmmim][BF4] 45.7 + 3.4 61.0 + 1.6 92.2 + 1.2 -14.5 + 1.4 -47.7 + 4.4 [emim][Tf2N] 25.3 + 1.3 35.6 + 1.4 51.5 + 1.2 -14.2 + 1.6 -46.9 + 3 [emmim][Tf2N] 28.6 + 1.2 39.6 + 1.4 60.5 + 1.5 -14.7 + 1.2 -48.7 + 4

4.1.2.3 Enthalpies and entropies of absorption

Further evidence of the limited influence of the hydrogen in the 2-position can be obtained by examining the enthalpy (∆h1) and entropy (∆s1) of absorption, as reported in Table 4.2. Within the reported error, the calculated values of ∆h1 and ∆s1 are independent of composition (x1) and equal to the infinite dilution values, as found from the van’t Hoff equations.6, 7

The experimental enthalpies and entropies for the [Tf2N] ILs, which also had the highest CO2 solubility, are the same regardless of the presence of the methyl group.

For the [PF6] and [BF4] ILs, it is difficult to draw a definite conclusion since the enthalpies and entropies are very close within the reported error. Since only three temperatures were examined, the experimental uncertainty is relatively large. Despite

72 this, it does appear that the enthalpies for the ILs with the methyl group substituted on the second carbon are lower by 1-3 kJ/mol.

Based on these findings, it is apparent that the presence of a hydrogen on the

C2 carbon affects the CO2 solubility only slightly; it plays a very small role in determining the overall high solubility of CO2 in imidazolium-based ILs. The results show instead that CO2 solubility is affected much more by the nature of the anion; the

ILs with the [Tf2N] anion had a much greater CO2 solubility than those with either the

[PF6] or [BF4] anions. This may be due to the fact that the [Tf2N] anion is more basic142 and contains two fluoroalkyl groups. These results are consistent with the

ATR-IR studies that showed that CO2 solubility in [bmim][PF6] and [bmim][BF4] is governed by interactions with the anion.141

Molecular simulations of CO2 in [bmim][PF6] and [bmmim][PF6] are also consistent with the experimental data presented here.95 The simulations indicate that the CO2 is localized around the anion and exchanging the hydrogen for a methyl group on the C2 position has very little effect on the CO2 molecules.

4.1.3 Effect of cation with [Tf2N] anion

In the previous sections, the experimental evidence suggested that the anion, particularly the [Tf2N] anion, played a significant role in determining the solubility of carbon dioxide in the ionic liquids. In this section, the effects of different cations with the [Tf2N] anion will be discussed. Specifically, how changing the cation to an tetraalkylammonium or pyrrolidinium affects CO2 solubility is investigated.

73 4.1.3.1 Solubility isotherms

Figures 4.10 and 4.11 show the previously presented isotherms as well as isotherms for methyl-tri-butyl ammonium bis(trifluoromethylsulfonyl) imide

([MeBu3N][Tf2N]), hexyl-tri-butyl ammonium bis(trifluoromethylsulfonyl) imide

([HeBu3N][Tf2N]), and methyl-butyl pyrrolidinium bis(trifluoromethylsulfonyl) imide ([MeBuPyrr][Tf2N]). Also shown in Figure 4.11 is the CO2 absorption in tri- isobutyl-methyl phosphonium paratoluene sulfonate ([iBu3MeP][TOS]).

o The absorption in [MeBu3N][Tf2N] was measured, only at 25 C, using the stainless steel bucket with a 90 minute equilibration time. [HeBu3N][Tf2N] and

[MeBuPyrr][Tf2N] were measured using quartz bucket 1, also with 90 minute equilibration times. Slightly longer equilibration times were needed for

o o [HeBu3N][Tf2N], so experiments were repeated at 10 C and 50 C with 180 minute equilibration times (although 120 minutes would have been sufficient). The

[iBu3MeP][TOS] absorption was measured in the stainless steel bucket and allowed

180 minutes. Tables of all the raw data can be found in Appendix D.

The most notable attribute seen in these two figures is that the ionic liquids with the [Tf2N] anion show similar, high CO2 solubility, regardless of the cation. Of the

[Tf2N] based ILs, [MeBuPyrr][Tf2N] and [bmim][Tf2N] had the highest solubility.

These were closely followed by [emim][Tf2N], [HeBu3N][Tf2N], [emmim][Tf2N], and then [MeBu3N][Tf2N]. It appears that a longer alkyl chain on the cation, such as the hexyl vs. methyl chain on the tetraalkylammonium cation or the butyl vs. ethyl chain on the imidazolium cation, slightly increases the solubility. But these changes

74

0.35 0.30 0.25 [MeBuPyrr][Tf2N] 0.20 [bmim][Tf2N] [HeBu N][Tf N] 0.15 3 2 [MeBu3N][Tf2N]

0.10 [emim][Tf2N] Mole Fraction [emmim][Tf N] 0.05 2 [bmim][PF6] 0.00 [bmmim][PF ] 02468101214 6 [bmim][BF4] [bmmim][BF ] Pressure (bar) 4

o Figure 4.10 CO2 solubility in various ionic liquids at 25 C

0.35 0.30

0.25 [MeBuPyrr][Tf2N] [bmim][Tf N] 0.20 2 [HeBu3N][Tf2N] 0.15 [emim][Tf2N]

0.10 [emmim][Tf2N] Mole Fraction [bmim][PF ] 0.05 6 [bmim][BF4] 0.00 [bmmim][PF ] 02468101214 6 [bmmim][BF4] [iBu MeP][Tosylate] Pressure (bar) 3

o Figure 4.11 CO2 solubility in various ionic liquids at 50 C

75 are minor compared to the effect of the anion. It is also interesting that the

[iBu3MeP][TOS] ionic liquid exhibits a CO2 solubility comparable to [bmim][PF6] and [bmim][BF4]. But, as was pointed out in Chapter 3, this sample from Cytec probably contained significant impurities. Since any effects these impurities may have on CO2 solubility are unknown at this point, these data should be considered an estimate only.

4.1.3.2 Henry’s constants and enthalpies and entropies of absorption

The Henry’s constants for each of these additional systems are given in Table 4.3.

TABLE 4.3

HENRY’S CONSTANTS FOR CO2 IN SEVERAL ILS

Ionic Liquid H (bar) 10 oC 25 oC 50 oC [MeBu3N][Tf2N] 43.5 + 1.3 [HeBu3N][Tf2N] 35.3 + 8.2 42.6 + 5.6 65.7 + 8.3 [MeBuPyrr][Tf2N] 28.7 + 6.1 37.4 + 3.9 51.5 + 1.2 [iBu3MeP][TOS] 103.5 + 5.2

In all the [Tf2N] ILs, the reported Henry’s constants are comparable to those reported in the previous sections (Tables 4.1 and 4.2) which range from 25 bar to 60 bar over the temperature range. The [iBu3MeP][TOS] values are slightly higher than any of the other ILs.

Baltus and coworkers presented Henry’s constants for CO2 in several different

115 ionic liquids. They reported values of 52 + 5 bar in [C3mim][PF6], 37 + 7 bar in

[C3mim][Tf2N], 37 + 3 bar in [bmim][Tf2N], 35 + 5 bar in [C6mim][Tf2N], and 30 + 1

76 bar in [C8mim][Tf2N], all at ambient temperature. These values are consistent with the Henry’s constants reported here. Also, the same trend is seen where increasing chain length on the cation increases the CO2 solubility.

The enthalpies and entropies of absorption for CO2 in [HeBu3N][Tf2N] and

[MeBuPyrr][Tf2N] are given in Table 4.4. Again, these are very comparable to those measured in [bmim][Tf2N], [emim][Tf2N], and [emmim][Tf2N].

TABLE 4.4

ENTHALPIES AND ENTROPIES OF ABSORPTION FOR CO2 IN

[HeBu3N][Tf2N] AND [MeBuPyrr][Tf2N]

Ionic Liquid ∆h (kJ/mol) ∆s (J/mol K)

[HeBu3N][Tf2N] -11.9 + 6.3 -39.5 + 20.7 [MeBuPyrr][Tf2N] -11.1 + 4.0 -36.5 + 13.1

4.2 Other Gases Solubilities

The solubilities of a series of different gases in several ionic liquids are presented here. The gases are ethylene, ethane, methane, nitrous oxide, benzene vapor, hydrogen, carbon monoxide, oxygen, nitrogen, and argon. Carbon dioxide solubilities from Section 4.1 will also be used in the comparisons. Water solubilities in [bmim][PF6] will be used for comparison to the other gases, the details of which are presented in Chapter 5. These particular gases were chosen for several reasons.

Carbon dioxide solubility is important due to the possibility of using supercritical

CO2 to extract solutes from the ILs. Ethylene, hydrogen, carbon monoxide, and

77 oxygen are reactants in several of the types of reactions studied in ILs, such as hydroformylations, hydrogenations, and oxidations. Considering methane, ethane, and ethylene enables the influence of hydrocarbon size and double versus single bonds to be studied. Nitrogen and argon serve as inert probes that assist in examining the solvent/solute interactions. Carbon dioxide, nitrogen, and methane are also interesting due to their implications in terms of gas separations (see Chapter 6). In addition to carbon dioxide, gases such as nitrous oxide, nitric oxide, and sulfur dioxide are typically present in flue gases and their removal is an important separation issue. Therefore, their solubilities in ionic liquids is also interesting.

7 4.2.1 [bmim][PF6]

The absorption of C2H4, C2H6, CH4, O2, Ar, CO, H2, N2 into [bmim][PF6] was measured up to a gas pressure of 13 bar at three temperatures: 10 °C, 25 °C, and 50

°C.

4.2.1.1 Solubility isotherms

Most runs were allowed an equilibration time of 90 min at each pressure, which was found to be sufficient. The exceptions were CO2 at 10 °C, which was allowed

180 min, and CH4 at 25 °C, which was allowed 120 min. It should be noted that 90 min would have been sufficient to attain equilibrium for these runs as well, but the longer times were allowed merely as a check. The C2H4 runs at all temperatures were measured after 180 min per point, although equilibrium was reached after about 130

78 min. All measurements were made using the stainless steel bucket. Tables of all the raw data can be found in Appendix D.

As seen in Figure 4.12, the C2H4 solubility in the IL at the three temperatures is linear with pressure. This trend is seen with all the gases examined here other than

CO2, so it is sufficient to just use Henry’s constants to describe their behavior rather than showing the individual isotherms. These Henry’s constants are discussed in the next section. A comparison of the solubility of CO2, C2H4, C2H6, CH4, O2, and Ar in the IL at 25 °C is shown in Figure 4.13. Carbon dioxide has the largest solubility, followed by ethylene, ethane, and then methane. Oxygen and argon both have very low solubilities, almost falling along the x-axis in Figure 4.13. The low-molecular weight gases H2, CO, and N2 all had solubilities below the detection limit of the apparatus. These limits are discussed further in the following section on Henry’s constants.

0.12 10 oC 0.10 25 oC 50 oC

tion 0.08

0.06

0.04 Mole Frac 0.02

0.00 02468101214

Pressure (bar)

o o o Figure 4.12 C2H4 solubility in [bmim][PF6] at 10 C, 25 C, and 50 C

79

0.30 CO 2 CH4 0.25 C2H4 Ar C H O 0.20 2 6 2

0.15

0.10 Mole Fraction 0.05

0.00 02468101214

Pressure (bar)

o Figure 4.13 Solubility in various gases in [bmim][PF6] at 25 C

4.2.1.2 Henry’s constants

Equation 2.8 implies that, for gases that behave nearly ideally, the solubility is linearly related to the pressure; this relation holds for the experimental measurements of C2H4, C2H6, CH4, O2, and Ar. Therefore, those Henry’s constants were found by calculating fitting the data to a straight line using a least squares method and taking the slope. All these values, along with Henry’s constants for CO2 (presented in

Section 4.1) and water vapor in [bmim][PF6], which will be discussed in the following chapter (Section 5.1), are shown in Table 4.5. The Henry’s constants span a large range: from 0.07 bar for H2O to 23,000 bar for O2, both at 10 °C.

As described in Chapter 2, the microbalance measures the gas solubility on a mass basis. Therefore, the detection limit depends on the molecular weight of the gas. The low-molecular weight gases H2, CO, and N2 all had solubilities below the detection

80 limit of the apparatus. Using the lowest solubility measured (O2 at 10 °C) as the minimum, measurable change in mass, the minimum Henry’s constants that could possibly be measured for gases with molecular weights of 2 g/mol (H2) and 28 g/mol

(CO and N2) are estimated to be 1500 bar and 20,000 bar, respectively. Therefore, the Henry’s constants for CO and N2 are greater than 20,000 bar and greater than

1500 bar for H2.

TABLE 4.5

HENRY’S CONSTANTS FOR SEVERAL GASES IN [bmim][PF6]

10 °C 25 °C 50 °C 6 H2O 0.09 + 0.02 0.17 + 0.02 0.45 + 0.05 7 CO2 38.7 + 0.4 53.4 + 0.3 81.3 + 0.5 7 C2H4 142 + 14 173 + 17 221 + 22 7 C2H6 284 + 47 355 + 36 404 + 41 7 CH4 1480 + 110 1690 + 180 1310 + 290 7 O2 23000 + 15000 8000 + 5400 1550 + 170 Ar 7 22000 + 10000 8000 + 3800 1340 + 220 CO 7 non-detect (>20,000) non-detect (>20,000) non-detect (>20,000) 7 N2 non-detect (>20,000) non-detect (>20,000) non-detect (>20,000) 7 H2 non-detect (>1500) non-detect (>1500) non-detect (>1500)

The absorption and desorption branches of the isotherms serve as upper and lower bounds for the true equilibrium values, as described earlier. Typically, the hysteresis between the absorption and desorption isotherms was less than 1 or 2%. However, for two of the ethane runs, this hysteresis was as large as 20%. To estimate the error bars for the linear fits of the data, a method was used in which lines were drawn so the normalized deviation of the data points (including both absorption and desorption

81 data) outside this range was less than 10%. A detailed example of these error calculations are given in Appendix B.

8 4.2.2 Other gases in [bmim][BF4]

The absorption of CH4, CO, and N2 into [bmim][BF4] was measured up to a gas pressure of 13 bar at three temperatures: 10 °C, 25 °C, and 50 °C. The C6H6 solubility was measured up to approximately 80% of its vapor pressure for 10 °C and

25 °C and up to about 50% of its vapor pressure for 40 °C and 50 °C. Tables of all the raw data can be found in Appendix D.

4.2.2.1 Solubility isotherms

The methane experiments were made using the sample from Professor Tom

Welton’s group in the stainless steel bucket, allowing 90 minutes for equilibration.

One experiment at 50 oC was allowed 180 minutes, but 90 minutes was sufficient.

Experiments were repeated at all three temperatures using the sample made by Jacob

M. Crosthwaite in quartz bucket 4, again allowing 90 minutes to equilibrate. These isotherms are all relatively linear (see, for example, Figure 4.16), so again, it is most constructive to present them in terms of the Henry’s constants, as in the following section. Both N2 and CO were below the detection limit of the apparatus.

The benzene experiments were done using the sample from Professor Tom Welton’s group in the stainless steel bucket. 180 minutes were allowed for equilibration at all temperatures except 50 oC, which was only given 90 minutes. The 10 °C, 25 °C, and

50 °C data are plotted in Figure 4.14. The 40 °C data were left off for simplicity.

82 This figure is plotted as mole fraction of benzene versus the ratio of the pressure of the benzene to its vapor pressure (Pvap). The vapor pressure of benzene, calculated using Antoine’s equation,143 is 0.061 bar at 10 °C, 0.126 bar at 25 °C, 0.244 bar at 40

°C, and 0.362 bar at 50 °C. Also plotted in Figure 4.14 as the solid square is the liquid-liquid equilibrium value for [bmim][BF4] in contact with a liquid benzene phase at 25 oC.8 This value is equivalent to the point when the pressure of benzene is equal to its vapor pressure; the vapor equilibrium data extrapolates quite nicely to this point.

0.6 10 oC 0.5 25 oC o 0.4 50 C

0.3

0.2 Mole Fraction 0.1

0.0 0.00.20.40.60.81.0 vap P / P o o o Figure 4.14 Solubility of C6H6 in [bmim][BF4] at 10 C, 25 C, and 50 C along the liquid-liquid equilibrium value at 25 oC8

4.2.2.2 Henry’s constants and infinite dilution activity coefficients.

Once again, Henry’s constants can be determined from the linear slopes of the solubility isotherms. These values for [bmim][BF4] are given in Table 4.6. The

83 benzene solubilities are significantly larger than the other gases. Methane had the lowest measurable solubility; the solubility limits for CO and N2 are also reported.

Using Equation 2.11, Henry’s constants can be converted to infinite dilution activity coefficients (γ ∞ ) if the vapor pressure is known. For benzene, these values are 2.0 at 10 oC, 2.1 at 25 oC, and 2.2 at both 40 oC and 50 oC. Other researchers have

∞ o measured γ for benzene in different ILs with the [Tf2N] anion. At 50 C, Heintz et

∞ al. report γ for benzene in [emim][Tf2N] and [emmim][Tf2N] to be 1.179 and

48 ∞ 1.100, respectively. Krummen et al. give γ values of 1.36 for [mmim][Tf2N]

(1,3-dimethylimidazolium bis(trifluoromethylsulfonyl) imide), 1.21 for

45 [emim][Tf2N], and 0.903 for [bmim][Tf2N]. The ILs with the [Tf2N] anion have smaller deviations from ideality compared to [bmim][BF4], indicating that the [Tf2N] increases the ILs affinity for benzene relative to [BF4].

TABLE 4.6

HENRY’S CONSTANTS FOR SEVERAL GASES IN [bmim][BF4]

10 °C 25 °C 40 °C 50 °C C6H6 0.12 + 0.02 0.27 + 0.02 0.54 + 0.02 0.78 + 0.02 CO2 40.8 + 2.7 56.5 + 0.3 88.9 + 0.6 CH4 1180 + 250 1560 + 320 2980 + 660 CO non-detect non-detect non-detect (>20,000) (>20,000) (>20,000) N2 non-detect non-detect non-detect (>20,000) (>20,000) (>20,000)

84 4.2.3 Other gases in [bmim][Tf2N]

The absorption of C2H4, C2H6, CH4, O2, N2O, and N2 into [bmim][Tf2N] was measured up to a gas pressure of 13 bar at three temperatures: 10 °C, 25 °C, and 50

°C.

4.2.3.1 Solubility isotherms

All the experiments were conducted using quartz bucket 1 and a 90 minute equilibration with the Covalent sample. Multiple measurements were made with

C2H6 and CH4 under the same conditions. Experiments with N2O were repeated at all three temperatures using quartz bucket 4 and allowing 180 minutes for equilibration.

Again, 90 minutes would have been sufficient, and there was no noticeable difference between the runs. Tables of all the raw data can be found in Appendix D.

o The 25 C isotherms for the various gases in [bmim][Tf2N] are plotted in Figure

4.15. Nitrous oxide and carbon dioxide have essentially the same solubility, which is significantly higher than the other gases. Ethylene is the next most soluble followed by ethane. Methane is slightly more soluble than oxygen, but both have fairly low solubilities. N2 was below the detection limit. The gas solubilities at other temperatures exhibit the same trend as shown in Figure 4.15. This trend is also the same as was seen with [bmim][PF6] (Figure 4.13), but all the gases are more soluble in [bmim][Tf2N].

85 0.30 CO 2 CH4 0.25 N O 2 O2

on C2H4 ti 0.20 C2H6 0.15

0.10 Mole Frac 0.05

0.00 0 2 4 6 8 10 12 14 Pressure (bar) o Figure 4.15 Solubility of a series of gases in [bmim][Tf2N] at 25 C

4.2.3.2 Henry’s constants

The Henry’s constants for each of these gases in [bmim][Tf2N] are listed in Table

4.7. These values will be compared to the other ILs in the following section.

TABLE 4.7

HENRY’S CONSTANTS FOR SEVERAL GASES IN [bmim][Tf2N]

10 °C 25 °C 50 °C CO2 27.1 + 5.8 33.0 + 1.3 49.1 + 1.4 N2O 25.1 + 5.2 33.4 + 7.0 48.4 + 10.1 C2H4 70.7 + 3.5 87.7 + 4.3 110.3 + 5.5 C2H6 98.5 + 4.9 112.2 + 5.6 150.9 + 7.6 CH4 490 + 260 690 + 200 780 + 400 O2 4770 + 830 2480 + 690 1300 + 130 N2 non-detect (>20,000) non-detect (>20,000) non-detect (>20,000)

86 4.2.4 Comparison between ionic liquids

Figure 4.4 showed the high solubility CO2 isotherms for the three ionic liquids.

Figure 4.16 shows the lower solubility CH4 isotherms for the same three ionic liquids.

Again, [bmim][Tf2N] has the highest solubility, whereas little difference is seen for the other two. It is also worthwhile to point out the larger degree of scatter seen in the data due to a smaller mass absorption. This larger degree of scatter between the absorption and desorption isotherms is reflected in the larger uncertainties reported for the lower solubility Henry’s constants.

0.018 [bmim][Tf N] 0.016 2 [bmim][PF ] 0.014 6 [bmim][BF ] 0.012 4 0.010 0.008 0.006

Mole Fraction 0.004 0.002 0.000 02468101214 Pressure (bar)

Figure 4.16 Solubility of CH4 in [bmim][PF6] , [bmim][BF4] , and [bmim][Tf2N]

The Henry’s constants for the series of gases in the three ionic liquids is plotted for comparison in Figure 4.17 at 25 oC. This plot emphasized how changing the anion from [PF6] to [BF4] has little affect on the solubility of any of the gases investigated. On the other hand, changing to a [Tf2N] anion increases the solubility of each of the gases; the Henry’s constant decreases approximately by a factor of two in each case. It is also apparent in Figure 4.17 that there are large differences in the

87 solubilities for different gases. For example, water is several orders of magnitude more soluble in the IL than the other gases indicating the possibility of using ILs to dry gases. CO2 is also at least an order of magnitude more soluble than the other gases suggesting the possibility of ILs as CO2- capture media. These differences will serve as the motivation for the gas separations experiments presented in Chapter 6.

) 100000 [bmim][PF6] (bar

s [bmim][BF ] t 10000 4 [bmim][Tf N] tan 1000 2 s

100 Beyond 10 Detection

Law Con Limit s ' 1

0.1

Henry 6 2 4 6 4 2 2 2 O O Ar O 2 H O 2 H H H O H N 6 2 2 C C H C C N C C

Figure 4.17 Comparison of Henry’s constants in [bmim][PF6] , [bmim][BF4] , and [bmim][Tf2N]

Berger and coworkers64 presented measurements for the Henry’s constants at

-3 -1 -1 room temperature for H2 in [bmim][PF6] and [bmim][BF4] of 3.0 x 10 mol L atm and 8.8 x 10-4 mol L-1 atm-1, respectively. Converting their data to conform with the

Henry’s constant convention used in the present work, they find a Henry’s constant of

5,700 bar for H2 in [bmim][PF6]. This value is consistent with the measurements

64 reported here. Berger et al. determined the H2 solubility using the pressure-drop technique (i.e. measuring the pressure decrease in a closed vessel as the gas dissolved into the liquid at constant temperature). The 50 mL vessel, pressurized to 50 atm,

88 contained just 10 mL of IL. For these conditions and the reported solubilities, the resulting pressure drop when the gas was absorbed into the liquid would only have been on the order of 0.005 atm. Thus, the values reported are probably only good order of magnitude estimates unless a highly accurate differential pressure transducer was employed. Unfortunately, the authors did not report the uncertainty of their

Henry’s constants, nor the accuracy of their pressure gauge.

A more recent work by Welton and coworkers reports hydrogen solubilities in several ionic liquids at 1 atm and either 293 K or 298 K measured using 1H NMR spectroscopy.70 They calculated Henry’s constants based on their single solubility value of 6600 bar for [bmim][PF6], 5800 bar for [bmim][BF4], and 4500 bar for

[bmim][Tf2N]. These values are all consistent with the present work where hydrogen

Henry’s constants greater than 1500 bar are not detectable using the gravimetric microbalance. Welton and coworkers also report hydrogen Henry’s constants of 3800 bar for [bmmim][Tf2N], 3900 bar for [bupy][Tf2N] (N-butylpyridinium bis(trifluoromethylsulfonyl)imide), 3700 bar for [bmpy][Tf2N] (N-butyl-N- methylpyrrolidinium bis(trifluoromethylsulfonyl) imide), 4900 bar for [bmim][SbF6]

(1-butyl-3-methylimidizolium hexafluoroantimonate), 4900 bar for [bmim][CF3COO]

(1-butyl-3-methylimidizolium trifluoroacetate), 5700 bar for [hmim][BF4] (1-hexyl-3- methylimidizolium tetrafluoroborate), 6400 bar for [omim][BF4] (1-octyl-3- methylimidizolium tetrafluoroborate), 4600 bar for [bmim][CF3SO3] (1-butyl-3- methylimidizolium triflate), and 700 bar for [P(C6H13)3(C14H29)][PF3(C2F5)3] (tri-n- hexyl-n-tetradecyl phosphonium trifluoro tri(pentafluoroethane) phosphate).70 Again, it is obvious that the anion can dramatically affect the gas solubility, as seen with the

89 variety of anions with the [bmim] cation. It does appear that changing the cation can also have a large effect on the hydrogen solubility (e.g. changing from imidazolium to pyridinium or pyrrolidinium increases the solubility).

Husson-Borg et al. report the Henry’s constants for oxygen in [bmim][BF4]; at 51 o 66 C, their Henry’s constants range between 326 and 355 bar. While O2 was not measured in [bmim][BF4] as part of the present work, Hussen-Borg’s Henry’s constants are smaller than what might be expected based on the Henry’s constants in

[bmim][PF6] and [bmim][Tf2N] reported here, which are an order of magnitude greater. Although the IL sample used Hussen-Borg et al. probably does contain some impurities since they do not clean the sample (other than removing water) prior to use, it is unlikely that contaminants can explain these differences. We currently do not have an explanation for this discrepancy.

4.2.5 Molecular interactions

As gas solubilities in liquids are governed by the interactions between the gas molecules and the solvent molecules, it is informative to look at these gases in terms of their polarizabilities and dipole and quadrapole moments. The reported values for these properties for each of the gases investigated are listed in Table 4.8. The positive or negative sign associated with the quadrapole moment distinguishes between the two quadrapole structures: a plus sign for the (+ − − +)structure and a minus sign for the (− + + −) structure.

90 TABLE 4.8

POLARIZABILITIES (α), DIPOLE MOMENTS (µ), AND QUADRAPOLE

MOMENTS (Q) OF THE GASES

α * 1024 (cm3) 121 µ * 1018 (e.s.u. * cm) 144 Q *1026 (e.s.u. * cm2) 144 H2O 1.48 1.84 0 C6H6 10.6 0 +3.6 CO2 2.64 0 -4.3 145 N2O 3.0 0.166 -3.0 145 C2H4 4.252 0 +1.5 C2H6 4.5 0 -0.65 CH4 2.6 0 0 145 O2 1.60 0 -0.39 Ar 1.64 0 0 CO 1.95 0.112 -2.5 N2 1.74 0 -1.52 H2 0.81 0 +0.662

For most of the gases, their solubilities in the ILs correlates reasonably well with their polarizability, as seen in Figure 4.18. This trend indicates that the solubility of these gases is governed by dispersion forces.

Outliers in this relationship between gas polarizability and solubility in the ILs were H2O, CO2, and N2O. The high solubility of water in the IL is likely due to the large dipole moment of water and the opportunities for hydrogen bonding. Kazarian and coworkers have used ATR-IR spectroscopy to confirm the presence of hydrogen

127 bonding between water molecules and several IL anions, including [PF6]. The relatively high solubility of carbon dioxide and nitrous oxide is likely due to their

91 [bmim][PF6] [bmim][Tf N] 100000 2 Exp. Limit for MW of 28 g/mol 10000 Ar O 2 Exp. Limit for O CH4 2 MW of 2 g/mol 1000 CH C2H6 4 C2H4 H2 N2 CO 100 C2H6 Henry's Constant (bar) C2H4 0123456 24 3 Polarizability (α * 10 cm )

Figure 4.18 Solubility dependence on polarizability for gases in [bmim][PF6] and [bmim][Tf2N]

large quadrapole moments as well as specific interactions between the gas and the anion. In another ATR-IR study of CO2 in [bmim][PF6] and [bmim][BF4], Kazarian and coworkers concluded that there was evidence of chemical interactions between the anion and the CO2 although they say those interactions were probably not large

141 enough to be the sole factor leading to the high CO2 solubility. They conclude that they observed Lewis acid-base interactions where the anion acts as the Lewis base.141

Molecular simulations of CO2 in [bmim][PF6] and [bmmim][PF6] also show that the

95 CO2 localizes around the anion.

Also shown in Figure 4.18 are vertical lines representing the polarizabilities for the non-detectable gases H2, N2, and CO and horizontal lines representing estimates of the solubility detection limits for the gases with molecular weights of 2 g/mol and

28 g/mol. If their solubilities were also governed by polarizability, predicted Henry’s constants would be approximately 20,000 bar, 6000 bar, and 5000 bar, for H2, N2, and

92 CO in [bmim][PF6], respectively. This predicted value for H2 is consistent with the detection limit on our apparatus, but is larger than the reported Henry’s constants of

64 70 70 5700 bar and 6600 bar for H2 in [bmim][PF6] and 4500 bar for H2 in

[bmim][Tf2N]. However, the predicted values for N2 and CO are both within the detection limits of the apparatus, indicating that their solubilities are not governed polarizability. Interestingly, both CO and N2 also have significant quadrapole moments, and yet both had immeasurably low solubilities. We currently do not have a reasonable explanation for this behavior.

4.2.6 Comparison to other solvents

It is instructive to compare the gas solubilities in the ionic liquids to those for gases dissolved in common polar and non-polar solvents. These Henry’s constants at

25 °C, listed in Table 4.9, show that, in general, the gases that are less soluble in the

IL are less soluble in the other solvents as well. However, carbon dioxide is more soluble in the ILs than the other solvents. Ethylene, ethane, methane, oxygen, and argon all have lower solubilities in the IL than in the other solvents.

93 TABLE 4.9

COMPARISON OF HENRY’S CONSTANTS OF VARIOUS GASES IN

[bmim][PF6], [bmim][BF4], AND [bmim][Tf2N] TO THOSE IN CONVENTIONAL

SOLVENTS

[bmim][PF6] [bmim][BF4] [bmim][Tf2N] 6 H2O 0.17 C6H6 0.27 CO2 53.4 56.5 33.0 N2O 33.4 C2H4 173 87.7 C2H6 355 112.2 CH4 1690 1560 690 O2 8000 2480 Ar 8000 CO non-detect (>20,000) non-detect (>20,000) N2 non-detect (>20,000) non-detect (>20,000) non-detect (>20,000) H2 non-detect (>1500)

Heptane 146 Cyclohexane 146 Benzene 146 Ethanol 146 Acetone 146 147 147 148 148 H2O 97 10 0.1 0.3 CO2 84.3 133.3 104.1 159.2 54.7 a C2H4 44.2 82.2 166.0 92.9 C2H6 31.7 43.0 68.1 148.2 105.2 CH4 293.4 309.4 487.8 791.6 552.2 O2 467.8 811.9 1241.0 1734.7 1208.7 Ar 407.4 684.6 1149.5 1626.1 1117.5 CO 587.7 1022.5 1516.8 2092.2 1312.7 N2 748.3 1331.5 2271.4 2820.1 1878.1 H2 1477.3 2446.3 3927.3 4902.0 3382.0 a for ethylene in hexane, not heptane

94 4.2.7 Enthalpies and entropies of absorption

The enthalpy and entropy values for the series of gases in the IL are listed in

Table 4.10 and 4.11. Within the reported error, the calculated values of ∆h1 and ∆s1 are independent of composition (x1) and equal to the values at infinite dilution, as found from the van’t Hoff equations.6

Not surprisingly, water, carbon dioxide, and nitrous oxide exhibited significantly stronger molecular interactions and a higher degree of ordering in the ILs than seen by the other gases. Their enthalpy and entropy values were much higher than those for the gases in non- polar solvents and very similar to the gases in small polar solvents like ethanol and acetone. Ethylene and ethane also yielded significant enthalpy and entropy changes, similar to those seen for the gases in both polar and non-polar solvents. Upon dissolution, methane shows essentially no interaction or ordering in the ILs. Argon and oxygen both exhibited positive enthalpy and entropy changes, indicating that their solubility is driven by the increase of disorder in the system. Although this phenomenon is not unusual for gases with low solubilities in liquids121 and is seen for several of the gases with low solubilities in the other organic solvents, the magnitude of the positive enthalpy and entropy changes are much greater for the gases in the ILs than in the other solvents. It should be noted that

Hussen-Borg et al. reported enthalpies and entropies of O2 absorption in [bmim][BF4]

that range between 2.9 and 19.9 kJ/mol and -40.1 and 12.5 J/mol K.66 One possible reason for the relatively large changes in enthalpy for the O2 and Ar in the

ILs relative to other solvents could be due to the high coulombic attraction between

95 TABLE 4.10

ENTHALPIES OF ABSORPTION FOR VARIOUS GASES IN [bmim][PF6],

[bmim][BF4], AND [bmim][Tf2N] AND OTHER SOLVENTS

∆h (kJ / mol) [bmim][PF6] [bmim][BF4] [bmim][Tf2N] 6 H2O -30 + 4 C6H6 -35.8 + 3.3 CO2 -16.1 + 2.2 -15.9 + 1.3 -11.4 + 4.0 N2O -11.2 + 7.4 C2H4 -8.4 + 3.7 -8.5 + 1.8 C2H6 -6.5 + 4.8 -8.2 + 1.8 CH4 2.1 + 5.6 -11.4 + 8.0 -8 + 18 O2 51.1 + 12.2 24.4 + 4.5 Ar 52.9 + 11.1 CO non-detect non-detect non-detect N2 non-detect non-detect non-detect H2 non-detect non-detect non-detect

∆h (kJ / mol) Heptane 146 Cyclohexane 146 Benzene 146 Ethanol 146 Acetone 146 147 147 b, 148 148 H2O -9.6 -21.6 -40.0 -38.0 CO2 -9.667 -5.556 -9.337 -12.795 -22.667 a C2H4 -7.461 -9.006 -9.077 C2H6 -11.162 -10.974 -9.211 -8.633 CH4 -0.066 -2.462 -1.277 -3.831 -8.633 O2 0.243 1.712 -1.218 0.126 Ar -1.223 -0.913 1.243 -0.385 1.930 CO 3.785 5.192 6.360 3.730 4.538 N2 2.139 4.254 0.456 1.746 H2 0.846 2.659 0.352 0.247 a for ethylene in hexane, not heptane b for water in methanol, not ethanol

96 TABLE 4.11

ENTROPIES OF ABSORPTION FOR VARIOUS GASES IN [bmim][PF6],

[bmim][BF4], AND [bmim][Tf2N] AND OTHER SOLVENTS

∆s (J / mol K) [bmim][PF6] [bmim][BF4] [bmim][Tf2N] 6 H2O -104 + 14 C6H6 -118.4 + 10.9 CO2 -53.2 + 6.9 -52.4 + 4.3 -37.6 + 13 N2O -36.8 + 24.3 C2H4 -27.6 + 12.2 -28.0 + 5.8 C2H6 -21.2 + 15.7 -27.2 + 5.8 CH4 0.7 + 18 -37.6 + 26.5 -26 + 49 O2 169 + 40 80.3 + 14.3 Ar 175 + 37 CO non-detect non-detect non-detect N2 non-detect non-detect non-detect H2 non-detect non-detect non-detect

∆s Heptane 146 Cyclohexane 146 Benzene 146 Ethanol 146 Acetone 146 (J/mol K) 147 147 b, 148 148 H2O -70 -92 -124 -114 CO2 -32.4 -18.5 -31.4 -42.9 -76.0 a C2H4 -25.1 -30.2 -30.5 C2H6 -37.4 -36.8 -30.9 -29.0 CH4 -12.7 -8.3 -4.3 -12.9 -9.5 O2 0.7 5.7 -4.1 0.4 Ar -4.2 -3.1 4.1 -1.3 6.4 CO 12.7 17.4 21.3 12.5 15.2 N2 7.0 14.2 1.5 5.8 H2 2.7 8.9 1.1 0.8

a for ethylene in hexane, not heptane b for water in methanol, not ethanol

97 the ions in the ILs that do not exist in the conventional solvents. Therefore, it takes more energy to insert the gas molecules into the IL than into the other solvents.

4.3 Other Systems

Over the course of this study, a few other systems were also investigated. Tables of all the raw data can be found in Appendix D.

Oxygen solubility was measured in [MeBu3N][Tf2N], [HeBu3N][Tf2N],

[MeBuPyrr][Tf2N], and [iBu3MeP][TOS]. The solubility isotherms in

[MeBu3N][Tf2N] and [iBu3MeP][TOS] were measured using the stainless steel bucket and equilibration times of 90 minutes and 180 minutes, respectively. The isotherms in [HeBu3N][Tf2N] and [MeBuPyrr][Tf2N] were measured using quartz bucket 1 and an equilibration time of 90 minutes. These Henry’s constants and enthalpies and entropies are given in Table 4.12. All four ILs had similar oxygen solubilities, all of which were were somewhat larger than those seen in the imidazolium ILs investigated. The enthalpies and entropies for [MeBu3N][Tf2N] and

[MeBuPyrr][Tf2N] were also smaller positive numbers relative to the imidazolium

ILs.

The solubility of C2H4 and C2H6 was measured in [bmim][NO3] containing approximately 0.5 wt% Ag. This system was of interest because silver has been used to enhance solubilities of olefins relative to paraffins149 and therefore could perhaps enhance the solubility of ethylene relative to ethane. This ionic liquid was chosen because silver is used in the synthesis and the IL still contained residual silver (no

98 TABLE 4.12

HENRY’S CONSTANTS AND ENTHALPIES AND ENTROPIES OF

ABSORPTION FOR O2 IN SEVERAL ILS

Ionic Liquid H (bar) 10 oC 25 oC 50 oC 70 oC [MeBu3N][Tf2N] 1270 + 250 1130 + 220 1180 + 230 [HeBu3N][Tf2N] 1350 + 640 [MeBuPyrr][Tf2N] 3310 + 580 1990 + 200 1100 + 110 [iBu3MeP][TOS] 1120 + 310

Ionic Liquid ∆h ∆s (kJ/mol) (J/mol K) [MeBu3N][Tf2N] 1 + 7 4 + 23 [MeBuPyrr][Tf2N] 20 + 5 68 + 17

additional silver was added). These isotherms were measured using the stainless steel bucket and allowed 120 minutes to equilibrate. There resulting Henry’s constants for

o C2H4 versus C2H6 were 206 + 21 bar versus 417 + 42 bar at 10 C, bar 251 + 25 versus 465 + 47 bar at 25 oC, and 310 + 31 bar versus 504 + 51 bar at 50 oC. At all three temperatures, the resulting solubility ratio is approximately 2, which is the same ratio seen for the ILs not containing any silver ([bmim][PF6] and [bmim][ Tf2N]). It is likely that 0.5 wt% Ag is not a sufficient amount of silver to see the enhancement.

4.4 Summary

CO2 has a high solubility in all the ILs studied and this high solubility depends mostly on the nature of the anion. The [Tf2N] anion increases all gas solubilities relative to [BF4] and [PF6] ILs. The [BF4] anion has little effect on the solubility of the gases relative to [PF6]. The large dipole moment and ability to hydrogen bond for

99 water and the large quadrapole moment of carbon dioxide and nitrous oxide as well as specific interactions between the gas and the anion are likely the governing forces leading to such high solubilities in the ionic liquids. The solubilities of other gases correlate fairly well with their polarizability.

100

CHAPTER 5

RESULTS – IONIC LIQUIDS AND WATER

This chapter addresses the phase behavior of several ionic liquids and water.

Section 5.1 presents work done to study the solubility of water vapor in three ionic liquids and looks at the effect that the anion or the chain length on the cation has on water solubility. Section 5.2 compares the vapor solubility results to results from liquid/liquid equilibrium measurements of the same ionic liquids and water. Section

5.3 addresses some practical issues incurred by the ionic liquid and water mutual solubilities, in particular, how the presence of water affects the solubility of carbon dioxide in the ionic liquid, techniques for removing water from the ionic liquid phase, and one technique for removing the ionic liquid from the aqueous phase by using activated carbon.

5.1 Water Vapor in Various Ionic Liquids6

The amount of water absorbed by the IL when exposed to various pressures of water vapor was measured for three ionic liquids (Sachem [bmim][PF6], QUB

[C8mim][PF6], and QUB [C8mim][BF4]) at three different temperatures: 10 °C, 25 °C, and 35 °C. The low pressure VLE data for [bmim][PF6] was also collected at 50 °C.

101 Additional runs were performed at 25 °C with the Sachem [C8mim][PF6] and the cleaned QUB [C8mim][BF4]. These runs were performed to investigate the effect of chloride contamination on the water vapor solubility. The QUB [C8mim][PF6] sample contained approximately 1400 ppm chloride compared to the 14 ppm chloride in the Sachem [C8mim][PF6] sample. The cleaned QUB [C8mim][BF4] sample contained less than 300 ppm chloride compared to the 950 ppm chloride in the original sample.

5.1.1 Solubility isotherms

These results, plotted as the weight percent of water absorbed into the ionic liquids versus the ratio of the pressure of water to the vapor pressure of the water

(Psat), are shown in Figures 5.1 – 5.3. Tables of all the raw data can be found in

Appendix D. The Sachem [bmim][PF6], QUB [C8mim][PF6], and original QUB

5.0 50 oC o %) 50 C - Karl Fischer 35 oC o 4.0 o 35 C - Karl Fischer 25 C 25 oC - Karl Fischer 10 oC ty (wt. 3.0

2.0

1.0

Water Solubili 0.0 0.0 0.2 0.4 0.6 0.8 1.0 sat P / P

Figure 5.1 Solubility of water vapor in [bmim][PF6]

102 2.0 o

%)

. 35 C t 25 oC w 1.5 10 oC 25 oC - Karl Fischer

bility ( 1.0

0.5

Water Solu 0.0 0.0 0.2 0.4 0.6 0.8 1.0 sat P / P

Figure 5.2 Solubility of water vapor in [C8mim][PF6]

) 12 35 oC t. % 10 25 oC o

(w 10 C 8 25 oC - Karl Fischer lity i

b 6 lu 4

2

Water So 0 0.0 0.2 0.4 0.6 0.8 1.0 sat P / P

Figure 5.3 Solubility of water vapor in [C8mim][BF4]

[C8mim][BF4] data are shown by the solid symbols. The additional runs with the

Sachem [C8mim][PF6] sample and the cleaned QUB [C8mim][BF4] sample are shown as crosses. The open symbols (plotted where P/Psat = 1) are independent measurements of the solubility of liquid water in the ILs. These data will be

103 discussed in Section 5.2. As can be seen in Figures 5.2 and 5.3, chloride impurities at this level little to no effect on the water vapor solubility. The corresponding values of

Psat at each temperature, calculated using the Antoine’s equation,143 are all less than

0.122 bar and are listed in Table 5.1. The solid lines are meant to guide the eye and the dotted lines indicate the extrapolation of the data out to the vapor pressure of water (P/Psat = 1).

Most of the isotherms were run from 10-9 bar to about 80% of the vapor pressure of water to avoid any possibility of condensation of water on the microbalance internals. However, the isotherms for [bmim][PF6] at 25 °C and [C8mim][BF4] at 25

°C and 35 °C were safely extended up to 93% of the vapor pressure.

Equilibration times of 1 h for [bmim][PF6] and 3 h for [C8mim][PF6] and

[C8mim][BF4] were allowed for each pressure. Since equilibration occurred solely by diffusion, it is not surprising that longer equilibration times would be required for the more viscous samples.5 These equilibration times resulted in less than 0.15% difference between absorption and desorption. Also, several points were collected for

[bmim][PF6] after an equilibration time of 16 h, and these values were consistent with those taken after the shorter equilibration times.

As shown in Figures 5.1 – 5.3, the solubility of water vapor is greatest in

[C8mim][BF4], which is not surprising since [bmim][BF4] is totally miscible with

42 water at ambient conditions. A direct comparison of [C8mim][PF6] with

[C8mim][BF4] (Figures 5.2 and 5.3) emphasizes the importance of the anion in determining the amount of water vapor absorbed. The van der Waals volume for the

3 3 anion [PF6] has been calculated as 68 Å , whereas the volume for [BF4] is only 48 Å ,

104 150 resulting in a higher charge density for [BF4] than [PF6]. Jureviciute et al. suggested that water is more soluble in systems where the counter anion is tetrafluoroborate rather than hexafluorophosphate since the [BF4] is smaller, allowing

151 more room for the water. Comparing [bmim][PF6] and [C8mim][PF6] in Figures

5.1 and 5.2, it is clear that increasing the length of the alkyl chain decreases the solubility of water, as would be expected.

Isotherms for all three compounds exhibit nonlinear increases as the amount of water absorbed in the sample increases at higher pressures, a trend that is different than the linear trend seen with the other gases or the nonlinear “flattening” of the curve seen with CO2. This phenomenon suggests that water is sufficiently soluble in the ILs that water-water interactions are important, as well as water-ion interactions; i.e. the concentrations are well above what could be considered infinite dilution. The

IL [C8mim][BF4], which has the highest solubility of water, also shows the sharpest increase in the amount of water absorbed as the pressure rises.

It should be noted that the IL samples were dried (and degassed) scrupulously before the introduction of water vapor by heating the IL sample at 75 °C under vacuum at about 8 × 10-9 bar until the mass of the sample remained constant.

Constant mass was readily achieved for [C8mim][BF4] and [bmim][PF6]. However, when drying the [C8mim][PF6] prior to the run, the mass continued to decrease for over 30 h. When the temperature was lowered to 58 °C, the mass stopped decreasing,

-9 suggesting that either the [C8mim][PF6] decomposes slightly at 75 °C or that 8 × 10 bar is on the order of magnitude of the vapor pressure of the IL itself at 75 °C.

Hardacre reports that both [PF6] and [BF4] decompose in the presence of water, so the

105 139 loss of [C8mim][PF6] is most likely due to decomposition. Regardless, the vapor pressures of all three of the ILs studied is not significantly greater than 8 × 10-9 bar at

75 °C. All other samples in this work were heated to 50 oC at 8 × 10-9 bar and no decrease in mass was seen.

5.1.2 Henry’s constants and infinite-dilution activity coefficients

The derivation of Henry’s constants and activity coefficients were presented in

Chapter 2. Since solubility is linearly related to the pressure in the Henry’s law regime, these definitions are applicable only for the lowest pressures shown in

Figures 5.1 – 5.3. Thus, the low pressure solubilities of water in ILs can be reported as Henry’s constants or infinite-dilution activity coefficients, and both of these values are shown for each IL at each temperature in Table 5.1. These values were found by

nd rd fitting a polynomial to the data (2 order for [bmim][PF6] and [C8mim][PF6], 3 order for [C8mim][BF4]) and calculating the limiting slope as the pressure approaches zero. Deviations from the polynomial fits were less than 0.5%. The uncertainties were determined by using the Henry’s constant or infinite-dilution activity coefficient calculated for absorption and desorption as the upper and lower bounds.

The Henry’s law constants range from 0.033 bar at 10 °C for [C8mim][BF4] to

0.45 bar for [bmim][PF6] at 50 °C, all small values that indicate high solubility of water vapor in the ILs. The infinite dilution activity coefficients are all greater than

∞ unity, but none are excessively large. For comparison, Table 5.2 lists H1 and γ for

147, 148 water dissolved in several different organic solvents. The H1 values for water in all three ILs are much smaller than values for water in nonpolar hydrocarbons,

106 TABLE 5.1:

HENRY’S CONSTANTS, H1, AND INFINITE DILUTION ACTIVITY

∞ COEFFICIENTS, γ , FOR WATER IN [C8mim][BF4], [bmim][PF6], AND

a [C8mim][PF6]

sat T P [C8mim][BF4] [bmim][PF6] [C8mim][PF6] (°C) (bar)

∞ ∞ ∞ H1 (bar) γ H1 (bar) γ H1 (bar) γ 10 0.012 0.033 + 0.014 2.65 0.09 + 0.02 6.94 0.11 + 0.03 8.62 25 0.031 0.055 + 0.006 1.76 0.17 + 0.02 5.36 0.20 + 0.03 6.51 35 0.055 0.118 + 0.014 2.13 0.25 + 0.04 4.45 0.30 + 0.02 5.87 50 0.122 - - 0.45 + 0.05 3.73 - -

a ∞ The error in γ is consistent with that given for H1.

indicating a significantly higher affinity of water for the ILs than for nonpolar organics. Likewise, the infinite dilution activity coefficients for water in nonpolar hydrocarbons are extremely large, indicating that water has a high activity in these solutions, much preferring the vapor phase to dissolution in the hydrocarbon.

Conversely, the Henry’s law constants and infinite dilution activity coefficients of water in various polar organics (alcohols and an aldehyde) are quite similar to the values measured for the three ILs. In fact, the values for the water Henry’s constants in the ILs are closest to those in polar solvents such as ethanol and 2-propanol. This similarity is consistent with measurements with both absorption and fluorescence spectroscopic probes that indicate these particular ILs have an effective polarity roughly similar to short chain alcohols.73, 74

107 TABLE 5.2:

LITERATURE VALUES FOR HENRY’S CONSTANTS, H1, AND INFINITE

DILUTION ACTIVITY COEFFICIENTS, γ∞, FOR WATER IN VARIOUS

ORGANIC SOLVENTS

T Psat Methanol148 Ethanol148 2-Propanol148 Acetone148 (°C) (bar) ∞ ∞ ∞ ∞ H1 γ H1 γ H1 γ H1 γ (bar) (bar) (bar) (bar) 10 0.012 ------15 0.017 - - - - 0.10 5.88 - - 25 0.031 0.13 4.19 0.10 3.23 - - - - 35 0.055 0.09 1.64 - - - - 0.34 6.18 45 0.096 0.17 1.77 - - 0.34 3.54 0.54 5.63 50 0.122 0.40 3.28 ------55 0.157 0.27 1.72 - - 0.53 3.38 0.83 5.29

T Psat Benzene147 Carbon Cyclohexane147 (°C) (bar) Tetrachloride147 ∞ ∞ ∞ H 1 γ H 1 γ H 1 γ (bar) (bar) (bar) 10 0.012 6 500 25 2083 78 6500 15 0.017 ------25 0.031 10 323 37 1194 97 3129 35 0.055 13 236 46 836 105 1909 45 0.096 ------50 0.122 ------55 0.157 ------

108 5.1.3 Enthalpy and entropy of absorption

The ∆h1 and ∆s1 for the three ILs, calculated from equations (2.15) and (2.16), are listed in Table 5.3. The uncertainties reported were obtained by comparing the

TABLE 5.3:

ENTHALPY AND ENTROPY CHANGES FOR WATER ABSORBING IN

[C8mim][BF4], [bmim][PF6], AND [C8mim][PF6]

Ionic Liquid -∆h1 (kJ / mol) -∆s1 (J / mol K) [C8mim][BF4] 34 + 5 117 + 18 [bmim][PF6] 30 + 4 104 + 14 [C8mim][PF6] 30 + 5 102 + 17

enthalpies and entropies determined for the absorption and desorption branches of the isotherm. Enthalpies and entropies calculated from the van’t Hoff equation

(equations 2.17 and 2.18) are equivalent for the three different ILs within the range of error. Since the uncertainties in the enthalpies and entropies are greater than the differences in the values between the three different ILs, it is not possible to make any conclusions about the relative strength of interaction of the different ILs with water.

These interactions are similar to those seen for benzene in [bmim][BF4] and are significantly larger than any seen with the other gases in the ILs reported in Chapter

4.

The ∆h1 and ∆s1 for the absorption of water into various organics solvents are listed in Table 5.4, along with the enthalpy and entropy of vaporization of water,

147, 148, 152 which is essentially ∆h1 and ∆s1 for water absorbing in water.

109 TABLE 5.4:

LITERATURE VALUES FOR THE ENTHALPY AND ENTROPY CHANGES

FOR WATER ABSORBING IN VARIOUS ORGANIC LIQUIDS

-∆h1 (kJ / mol) -∆s1 (J / mol K) Liquid Water152 44 147 Methanol148 40 124 Acetone148 38 114 2-Propanol148 33 101 Benzene147 21.6 92 Toluene153 18.4 89 Carbon 18.0 90 Tetrachloride147 Cyclohexane147 9.6 70

The enthalpies for absorption of water vapor into polar and protic solvents is much greater than for its absorption into nonpolar solvents, indicating much stronger molecular interactions between water and the polar solvents (including opportunities for hydrogen-bonding). In addition, the entropy decrease upon absorption of water vapor into polar solvents indicates a much greater ordering in the liquid phase than when water dissolves in nonpolar solvents. The enthalpies and entropies of water absorption in the three ILs are most similar to water absorption into polar compounds like 2-propanol. Once again, this is consistent with solvatochromic studies that suggest the solvent strength of these ILs to be similar to short chain alcohols.73, 74

5.2 Ionic Liquid and Water Liquid-Liquid Equilibrium6

5.2.1 Ambient conditions

Liquid-liquid equilibrium (LLE) measurements were conducted at ambient conditions (22 + 1 °C and 0.98 + 0.03 bar) for all three ILs (Sachem [bmim][PF6],

110 QUB [C8mim][PF6], and QUB [C8mim][BF4]) and the results for the compositions of both the IL-rich phases and the water-rich phases are shown in Table 5.5. The mutual

TABLE 5.5:

LIQUID-LIQUID EQUILIBRIUM RESULTS FOR WATER WITH [C8mim][BF4],

[bmim][PF6], OR [C8mim][PF6] AT AMBIENT CONDITIONS

IL in Aqueous Water in Ionic Liquid Phase IL Phase wt. % mol fraction wt. % mol fraction -4 [C8mim][PF6] 0.7 + 0.1 3.50×10 1.3 + 0.5 0.20 -3 [bmim][PF6] 2.0 + 0.3 1.29×10 2.3 + 0.2 0.26 -3 [C8mim][BF4] 1.8 + 0.5 1.17×10 10.8 + 0.5 0.63

solubilities of water and [C8mim][PF6] are lower than those seen for the equivalent IL with a shorter alkyl chain, [bmim][PF6]. As observed in the vapor-liquid equilibrium measurements, changing the anion from [PF6] to [BF4] increases the mutual solubilities substantially, as over 10 wt% water dissolves in [C8mim][BF4]. These liquid-liquid equilibrium measurements of the amount of water dissolved in the IL- rich liquid phase are plotted as open points in Figures 5.1 through 5.3. These solubilities are roughly consistent with what would be predicted by extrapolating the absorption isotherms (dotted lines in Figures 5.1 through 5.3) to the point when the pressure of the water above the sample is equal to the water vapor pressure (P/Psat =

1). The LLE measurements were repeated for the low chloride Sachem [C8mim][PF6] sample and the cleaned QUB [C8mim][BF4] sample. The results were the same as shown in Table 5.5, within experimental uncertainty. Thus, chloride impurities at these levels (<1400 ppm) are not sufficient to affect the LLE with water.

111 These measurements are also reasonably consistent with measurements by other groups. Fadeev and Meagher reported the mutual solubilities for [bmim][PF6] and

[C8mim][PF6] with water, although without any indication of the method of analysis or of the uncertainty in their measurements.58 Their analysis of both phases of the

[bmim][PF6] system and the IL-rich phase of the [C8mim][PF6] system match these results within the experimental uncertainty. They reported a solubility of 0.35 wt.%

[C8mim][PF6] in water, which is about half the value we obtained. Seddon and co- workers reported, in graphical form, the solubility of water in the IL, for all three of

5 the IL studied here. Their values for [C8mim][PF6] and [C8mim][BF4] appear to be consistent with these measurements. However, their measurement of the solubility of water in [bmim][PF6] appears to be slightly lower than the results presented here

(about 1.5 wt.% instead of 2.0 wt.%). Alfassi et al. report a value 1.86 + 0.07 wt%

60 [bmim][PF6] dissolves in water. Overall, it appears that the measurements of the complete mutual solubilities of all three of these compounds reported in the present work are consistent with the partial data that has appeared elsewhere.5, 58 On the other hand, the solubilities of water in the ILs reported here are larger that those previously reported by Rogers and co-workers.101 Due to the relatively short contact times (on the order of minutes), their solutions may not have reached equilibrium at the time of the measurements. Experience during the course of these experiments has shown that several hours of vigorous agitation between the two phases is required for equilibrium to be achieved; even just stirring the phases without breaking the interface between the phases for a period of 24 h was not sufficient for equilibrium to be reached.

112

5.2.2 Comparison to other solvents

For comparison, Table 5.6 gives LLE data for various organic solvents with water.

The mutual solubilities of all three ILs and water are significantly higher than for any of the nonpolar hydrocarbons listed. By contrast, water is totally miscible with acetone, methanol, ethanol, and 2-propanol at room temperature.143 Mutual solubilities of longer chain alcohols with water can be quite high (see Table 5.6) and are similar to what is observed for the three ILs studied.

TABLE 5.6:

LIQUID-LIQUID EQUILIBRIUM RESULTS FOR WATER AND VARIOUS

ORGANICS AT AMBIENT CONDITIONS

Org. in Water in Org. Organic Aqueous Phase Phase wt. % mol fraction wt. % mol fraction Benzene 0.176 154 3.9×10-4 0.066 147 2.20×10-3 Toluene 0.052 155 1.0×10-4 0.045 153 2.80×10-3 Carbon 0.08 155 9.4×10-5 0.010 147 8.60×10-4 Tetrachloride Cyclohexane 0.006 156 1.3×10-5 0.007 147 3.40×10-4 n-Butanol 157 7.38 1.9×10-2 20.3 0.51 Cyclohexanol 3.77 7.1×10-3 12.1 0.43 157 n-Pentanol 157 1.92 3.8×10-3 9.0 0.34 n-Hexanol 157 0.56 1.0×10-3 6.7 0.29 n-Octanol 157 0.051 7.0×10-4 3.5 0.21 n-Decanol 157 3.7×10-3 4.2×10-6 4.0 0.27 n-Dodecanol 157 2.3×10-4 2.3×10-7 1.4 0.13

113 5.2.3 Elevated temperatures

Liquid-liquid equilibrium measurements were also collected by Timothy I.

Morrow in our laboratory at temperatures of 35 °C and 50 °C for [bmim][PF6] and these results are shown in Table 5.7. They are also plotted as the open symbols in

Figure 5.1. The liquid-liquid equilibrium values are larger than those predicted by the extrapolation of the VLE data, especially for the higher temperature points. This difference indicates that there is significant curvature in the VLE curves that is not fully predicted when the VLE measurements are limited to pressures much below the saturation pressure (i.e., VLE data at 50 °C could be only obtained up to about 40% of Psat due to equipment limitations). Although the temperature range is somewhat limited, it is clear that the [bmim][PF6] – water system exhibits upper critical solution temperature behavior, as was previously reported for [bmim][BF4] at lower temperatures.42 In other words, the mutual solubilities increase as the temperature is

TABLE 5.7:

LIQUID-LIQUID EQUILIBRIUM RESULTS FOR WATER AND [bmim][PF6] AT

VARIOUS TEMPERATURES

IL in Aqueous Water in IL Phase T (°C) Phase wt. % mol fraction wt. % mol fraction 25 2.0 + 0.3 1.29×10-3 2.3 + 0.2 0.26 35 2.2 + 0.2 1.40×10-3 2.7 + 0.3 0.30 50 2.7 + 1.3 1.74×10-3 4.0 + 0.3 0.40

114 increased. This information is important because it indicates that the magnitude of the cross-contamination of water-IL systems will be greater at higher temperatures.

5.3 Practical Issues Due to Cross-Contamination Between Phases

It is clear that the ionic liquids are capable of absorbing significant amounts of water, whether in contact with water vapor or liquid water. Previous articles have illustrated the dramatic affect the presence of water can have on IL physical properties, such as density, viscosity, and solvent strength.5, 73 Therefore, it is imperative that the water content of the ILs be considered when investigating physical properties and phase behavior.

5.3.1 Removing water from ionic liquid phase

As practiced by most research groups, ionic liquids can be dried under vacuum.

After drying under vacuum for six days at ambient temperature, the water content of

[bmim][PF6] was reduced to about 0.15 wt.%. Heating a water-saturated sample of

[bmim][PF6] to 75 °C under vacuum for 24 h without any mixing decreased the water content to 0.02 wt.%. Drying the ILs while continuously mixing at 75 °C under vacuum for one to two days typically can decrease the water content to less than 500 ppm. The actual time to achieve that low water content does depend on the quality of mixing and hydrophilicity of the ionic liquid.

115 5.3.2 Effect of water on gas solubilities

It is important to remove the water from the ionic liquids prior to making experimental measurements intended to establish the physical properties of the ionic liquids, otherwise the physical properties will be for the mixture rather than the pure compound. However, due to the significant water uptake by these ILs, it will be virtually impossible to use ionic liquids in any practical process without them absorbing some water. Therefore, it is also important to have an understanding of how the presence of water affects the behavior of the ionic liquids. The particularly relevant situation for this work was how water affected the solubility of CO2.

Experiments were conducted in our laboratories using the static high pressure apparatus to measure the CO2 solubility in dry and water-saturated [bmim][Tf2N].

This ionic liquid was chosen for these studies because while Hardacre reports that both [PF6] and [BF4] decompose in the presence of water, decomposition has not been

139 seen with the [Tf2N] ILs. These measurements were collected by Eric M. Saurer, an undergraduate researcher at the University of Notre Dame, along with Dr. Sudhir

N. V. K. Aki. The resulting isotherms at 25 oC are plotted in Figure 5.4 along with the 25 oC data collected at low pressures with the gravimetric microbalance

(presented previously in Chapter 4). The three replicate isotherms at high pressure for the dry sample (containing < 500 ppm water) are shown by the filled symbols, whereas the isotherm with the water-saturated sample (containing 1.58 wt% water) is shown using open squares. The raw data can be found in Appendix F. It is also worthwhile to emphasize the consistency between the low pressure data (solid circles)

116 0.8

0.6 Fraction

e 0.4 Mol

2 Wet IL 0.2 Dry IL CO Dry IL (low P) 0.0 0 10203040506070 CO Pressure (bar) 2

Figure 5.4 Solubility of CO2 in [bmim][Tf2N] at low and high pressures with dry and water saturated samples.

collected using the gravimetric method and the high pressure data collected with the static high pressure apparatus. As is obviously shown in Figure 5.4, the presence of water had no effect on the solubility of CO2 in the IL. This lack of influence bodes well for practical applications that will involve gas solubilities in ionic liquids, such as using ILs as a gas separation media (see Chapter 6). The extremely high solubility of water in these ILs indicates that they will probably contain some significant amount of water in any practical situation, as it would be virtually impossible to prevent any exposure to water in an industrial setting. Therefore it would be important to ensure the desired properties (such as high CO2 solubility relative to other gases) would not be lessened due to the presence of water.

Previous studies in our laboratory found that there was a dramatic difference in

62 CO2 solubility between a sample of [bmim][PF6] that was saturated with water and

61 on that had been dried to 0.15 wt% H2O. It should be noted that both these experiments were conducted before it was general practice to test the ILs for

117 impurities. While is it a possibility that the presence of water in the ILs plays a more significant role in [bmim][PF6] than in [bmim][Tf2N], the more likely explanation is that there were other impurities present in the first sample that resulted in a lower

CO2 solubility. Ionic liquids with the [PF6] anion are known now to degrade to HF in the presence of water,139 so there was almost certainly acidic degradation products in that initial sample.

5.3.3 Removing ionic liquid from the aqueous phase

The substantial solubility of these ionic liquids in the water phase poses additional separation concerns if water were used to extract solutes from the IL phase. These concerns are due to possible impacts ILs may have on aquatic ecosystems and potentially high costs of the ILs compared to other common organic solvents.

Ideally, the entire aqueous phase would be recycled, thus eliminating the loss of IL to the environment. If the entire aqueous phase could not be recycled, an additional separation step would be needed to remove the IL from the wastewater stream. One obvious technique for separating ILs from water would be to vaporize the water, but the high energy costs associated with evaporating the water from a dilute aqueous solution makes this method impractical.

One common method for removing organics from water is adsorption onto activated carbon (AC). Table 5.8 shows that AC does remove [bmim][PF6] from an aqueous solution. The results from the ICP-OES are consistent with those from the

UV-vis analysis, ensuring that both the cation and the anion are removed from the solution. Also included in the table for comparison are the results from

118 Chatzopoulous et al., who used activated carbon to remove toluene from water.158, 159

It takes about 50 times less activated carbon to remove toluene from water than to remove [bmim][PF6]. This result is expected since activated carbon is generally most efficient at removing small, non-polar compounds like toluene, rather than polar or ionic species like ILs. Although this work shows that AC could be used to purify the wastewater stream, it does not allow for the recovery of the IL. Therefore, there would still be a net loss of IL from a process, as well as the concern for the disposal of the AC/IL waste. Alternative methods for the separation and regeneration of ionic

TABLE 5.8:

PERCENT OF [bmim][PF6] REMAINING IN WATER USING ACTIVATED

CARBON (+ 3%)

159 Mass of AC / [bmim][PF6] Toluene Initial Mass of Contaminant 2 day eq. time 2 day eq. time 2 week eq. time UV-vis ICP-OES 0.060 - - - 25.4 0.061 - - - 28.9 0.076 - - - 33.1 0.078 - - - 20.9 0.182 - - - 18.2 0.294 99 - - - 1.31 82 80 - - 2.17 - - 88 - 3.37 56 46 - - 4.29 - - 64 - 5.31 21 15 - - 5.75 6 - - - 7.21 2 - - - 9.99 - - 0.15 -

119 liquids continue to be investigated by our research group. For example, recent work from our laboratory has shown that CO2 pressure can be used to force a phase split between ionic liquids and both water and organic liquids, even when the IL is initially in small concentrations. 110, 111

5.4 Summary

H2O has a high solubility in all three ILs studied and depends mostly on the nature of the anion. Also, increasing the alkyl chain length on the cation decreases the water solubility slightly. Although the results in Chapter 4 showed that the [BF4] anion versus the [PF6] anion had little effect on the gas solubilities, it does significantly increase an ILs affinity for water. Liquid-liquid equilibrium results were consistent with the vapor solubility results and also showed that a significant amount of IL dissolves in water. This cross-contamination between ionic liquid and aqueous phases will very likely cause separation concerns if ionic liquids are to be incorporated into an industrial process.

120

CHAPTER 6

IONIC LIQUIDS AS MEDIA FOR GAS SEPARATIONS

The purpose of this chapter is to provide evidence of the potential application of ionic liquids to gas separations. The first section provides a general background on gas separations, and the associated theory is discussed in Section 6.2. The ideal separation factors are presented in Section 6.3, along with justification for the gas mixtures chosen for this study. The results from the supported liquid membrane system and the absorber system are presented in Sections 6.4 and 6.5, respectively.

Section 6.6 includes simple energy calculations comparing CO2 absorption by ILs to the conventional technique. Finally, Section 6.7 addresses the improvements that would be necessary to make ionic liquids a viable competitor for CO2 absorption.

6.1 Introduction

The separation and purification of gases has great importance in a wide of variety applications.160 Gases used in industrial processes need to have high purities so the resulting products will also have high purities. Gas purity is also important in terms of emissions. Many impurities have detrimental effects on human health and the environment, which requires removal prior to release. These impurities can either originate from impurities in the feed gas (requiring a purification step prior to the

121 process) or, more commonly, are formed during the process as by-products (requiring a purification process prior to atmospheric release).

Absorption is one of the most common techniques for gas purification.161 In an absorption system, the gaseous compounds (typically the impurities) are transferred from the gas phase into the liquid solvent. The liquid is then regenerated in a separate step. Many techniques have been employed to improve the mass-transfer efficiency between the phases.161, 162 Another issue when choosing a solvent for absorption is to consider the solubility of the solvent in the gas phase. If the liquid evaporates into the vapor phase, the “purified” gas will end up contaminated with the absorption solvent.

Supported liquid membranes (SLMs) are another, less common, technique that also uses a liquid as the gas separation medium.163 In these systems, the pores of a membrane are filled with the solvent. The more soluble gas is able to permeate across the membrane, while the less soluble gas remains on the feed side. The major advantage of a supported liquid membrane system is that a large surface area is achieved with a small amount of solvent. Another advantage is the membranes do not require a regeneration step; the gas is continually desorbing out of the solvent due to a pressure and/or concentration gradient. However, one of the limiting factors inhibiting the use of SLMs is membrane instability. The flux of the gas across the membrane is affected by the thickness of the membrane. A thinner membrane yields a higher flux, but the thinner the layer of solvent, the quicker the solvent evaporates.

In both these separation techniques, the choice of solvent is one of the most important factors in determining their effectiveness. In order for a new technique to be competitive, it must not only be cost-efficient, but also have low energy

122 requirements and not cause additional environmental problems, such as the release of volatile organic compounds (VOCs). Ionic liquids’ lack of volatility leads to some unique advantages if used in either an absorber or SLM separation scheme. In both cases, any risk of contaminating the final gas stream with the solvent would be completely eliminated. For the specific case of the membranes, the issue of instability should also be eliminated; it should be possible to use very thin membranes without any risk of solvent evaporation.

6.2 Gas Separations Theory

6.2.1 Separations using membranes

A supported liquid membrane system consists of a porous membrane whose pores have been filled with the liquid to be used as the separation media. These supported liquid membranes can be represented by the solution diffusion model for dense or non-porous membranes.162 In this model, the diffusion of the gas into the liquid can be described by Fick’s law:

D N = i (c − c ) (6.1) i io iL lM

where Ni is the flux of the gas through the liquid, Di is the diffusion coefficient of

the gas in the liquid, LM is the length of the pore (which is the membrane thickness for membranes with straight pores), and c and c are the concentrations of the gas io iL in the liquid at the entrance of the pore (feed side) and the exit of the pore (permeate side), respectively. These concentrations of compound i relate to the partial pressure of i in the gas phase through Henry’s law:

123 c c H = io and H = iL (6.2) io p iL p io iL

where H and H are the Henry’s constants at the conditions (temperature and io iL pressure) on the feed side and permeate side, respectively. There will be a pressure gradient across the membrane, however Henry’s constants should be independent of the total pressure.121 Assuming the temperature will be approximately the same on both sides of the membrane and that the Henry’s constants, the Henry’s constants on the feed and the permeate side will be the same:

H = H = H (6.3) i io iL

Combining Equations 6.1 through 6.3, yields the following equation for the flux through the membrane:

H D N = i i (p − p ) (6.4) i io iL lM

Assuming there is no external mass transfer resistance so the pressures at the interface

( p and p ) are equal to the bulk pressures on the feed side ( p ) and on the io iL iF permeate side ( p ), Equation 6.4 is equivalent to the following equation: iP

H D N = i i (p − p ) (6.5) i iP iF lM

For a binary gas mixture, the separation factor (α A,B )is defined as

y A xA α A,B = (6.6) yB xB

124 where yA and yB are the mole fractions of gases A and B on the permeate side and

xA and xB are the mole fractions on the feed side. In the case where no sweep gas is used on the permeate side, the ratio of the fluxes is equal to the ratio of the mole fractions on the permeate side. In terms of the previously derived equation for gas flux through a dense membrane (eq. 6.5), this ratio is

N y H D (p − p ) A = A = A A AP AF (6.7) N y H D (p − p ) B B B B BP BF

Assuming the pressure drop across the membrane is sufficiently large (i.e. p << p ), Equation 6.7 can be rearranged to yield the ideal separation factor: AP AF

* y A xA H A DB α A,B = = (6.8) yB xB H B DA

As shown by Equation 6.8, the ideal separation factor depends on both transport properties (diffusion) and thermodynamic equilibria (gas solubilities). Henry’s constants for gases in ionic liquids, as reported in Chapter 4, have been measured, but the transport properties for those gases in the ILs are still unknown. However, diffusion coefficients for gases in liquids are frequently the same order of magnitude,164 whereas the Henry’s constants for the gases in ionic liquids are orders of magnitude different. Therefore, an approximate separation factor can be calculated by only knowing the Henry’s constants:

* H A α A,B ≈ (6.9) H B

If the separation system behaves ideally, the calculated separation factor should be equivalent to the experimentally measured separation factor. In the experiments, the mole fractions of the two gases are measured on both the permeate and the feed

125 sides; the separation factor from the experimental results can be calculated using

Equation 6.6.

6.2.2 Separations using absorber

In a standard absorber setup, the gas and liquid flow through the system in a counter-current configuration. The liquid absorbs the compounds of interest out of the feed gas stream, resulting in a “purified” gas stream and a “saturated” liquid stream leaving the absorber. In the static setup used in this work, only the gas phase is flowing. The ionic liquid phase is coated on glass beads in the absorber, rather than flowing through the absorber.

The simplest way to represent the efficiency of the absorber is to show the “break- through curve” for the system. A break-through curve plots the ratio of the concentration of the compound of interest detected in the effluent stream to its concentration in the feed stream as a function of time. This ratio is equal to zero if all of the desired compound is being removed from the gas stream and is equal to one if the desired compound is no longer being removed. The break-through time is the time when the feed-concentration “breaks through” the absorber (i.e. the ratio is one), indicating the system has become saturated and is no longer working as a separation system.

6.3 Ideal Separation Factors

The results presented in Chapters 4 and 5 showed that different gases have large solubility differences in ionic liquids such as [bmim][PF6], [bmim][BF4], and

126 6-8 [bmim][Tf2N]. For example, carbon dioxide has a much higher solubility in those

ILs than other gases such as ethylene, ethane, methane, oxygen, argon, nitrogen, carbon monoxide, and hydrogen. The ratios of Henry’s constants for each of the gases to CO2 for [bmim][PF6] are given in Table 6.1. Similar solubility ratios were

TABLE 6.1:

RATIOS OF HENRY’S CONSTANTS OF VARIOUS GASES IN [bmim][PF6] TO

CO2 IN [bmim][PF6]

Hgas / HCO2 C2H4 / CO2 C2H6 / CO2 CH4 / CO2 HCO2 (bar) 10 oC 3.7 + 0.4 7.3 + 1.2 38 + 3 38.7 + 0.5 25 oC 3.2 + 0.3 6.6 + 0.7 32 + 3 53.4 + 0.4 50 oC 2.7 + 0.3 5.0 + 0.5 16 + 4 81.3 + 0.6

* * * Hgas / O2 / Ar / N2 / CO / H2 / HCO2 (bar) HCO2 CO2 CO2 CO2 CO2 CO2 10 oC 594 + 388 568 + 259 >517 >517 >39 38.7 + 0.5 25 oC 150 + 101 150 + 71 >375 >375 >28 53.4 + 0.4 50 oC 19 + 2 16 + 3 >246 >246 >18 81.3 + 0.6

* N2, CO, and H2 all had solubilities below the detection limits of the apparatus. The numbers reported are based on the values calculated as the minimum detectable solubilities.7

8 also observed for [bmim][Tf2N] and [bmim][BF4]. These large ratios indicate that these ILs have the potential to capture CO2 from gas mixtures, particularly flue gases

(based on the N2 and O2 ratios) and natural gas (based on the CH4 ratio). As reported in Chapter 4, the temperature dependence of the solubility yields the enthalpy of absorption of CO2 into the ILs. Those enthalpy changes ranged from -11 to -16.1 kJ/mol.7 This value is indicative of physical association; chemical association would yield a significantly higher enthalpy change.

127 The capture of CO2 is a particularly interesting system for study. This separation is relevant in the purification of natural gas and flue gases. Natural gas can contain

160, 161 around 10% CO2, making it uneconomical for use without purification. Carbon dioxide, a by-product in combustion processes, is also generally considered a

“greenhouse gas” that has played a significant role in problems with global climate change. Therefore, the removal of CO2 from flue gases is an extremely important environmental issue.

Current CO2 capture systems typically employ amine-based absorption agents,

165 such as monoethanolamine (MEA). MEA has a high CO2 carrying capacity and a low hydrocarbon solubility, reacts quickly with CO2, and is relatively inexpensive, making it a popular choice in commercial processes.166 Yet there are several disadvantages associated with MEA, most notably its relatively high vapor pressure, which leads to fugitive emissions during regeneration, and its corrosive nature, which requires the use of dilute aqueous solutions of MEA.166 Also, degradation products can be formed due to side reactions between MEA and some minor constituents of

167 flue gas. Therefore, there is a need to find solvents capable of capturing CO2 without these disadvantages.

The solubility of water in these ionic liquids is also quite high; the Henry’s

o 6 constant for water in [bmim][PF6] is 0.17 + 0.3 bar at 25 C. Therefore, these ionic liquids would also be effective in removing any water from gas streams. A solvent with the ability to dry gases and remove CO2 simultaneously would be advantageous for purifying natural gas where, in the conventional technology, two different

128 separation steps are required to remove the water and CO2. These ILs have the potential to accomplish both separations in one step.

Other gas separations using ionic liquids should also be possible based on a comparison of the other gas solubilities. For example, the separation of olefins and parafins should be possible based on the measured solubility ratio of approximately 2 for ethylene to ethane in both [bmim][PF6] and [bmim][Tf2N]. Also, methane solubility was sufficiently larger than either oxygen or nitrogen in both [bmim][PF6] and [bmim][Tf2N] (solubility ratio of approximately 4 for CH4 and O2). Methane recovery from oxygen and/or nitrogen was not studied as a part of this work.

In this work, the potential of ionic liquids as a gas separation medium is illustrated by separating carbon dioxide from a mixture with either nitrogen or methane using 1-n-butyl-3-methylimidazolium hexafluorophosphate, or [bmim][PF6].

Both a supported liquid membrane system and conventional absorber system were used. Separation of a ethylene/ethane mixture was also investigated using the membrane system. Simple energy calculations were also completed to compare ionic liquids to MEA in a traditional absorption scheme and discuss future possibilities for using ILs as physical absorbents for CO2 capture.

6.4 Supported Ionic Liquid Membranes

The ionic liquid [bmim][PF6] was coated on three to five ceramic membranes, which run in parallel. Separations using three gas mixtures were considered: a 10% carbon dioxide in methane mixture was used to represent the purification of natural gas, a 50:50 mixture of ethylene and ethane was used to study olefin/paraffin

129 separations, and a 10% carbon dioxide in nitrogen was used to model the removal of

CO2 from air or flue gases. All systems were studied at room temperature; the permeate phase was measured periodically, and the resulting separation factors were calculated. The separation factors as a function of time for the CO2 in CH4 experiments are plotted in Figure 6.1. The resulting separation factors equilibrate

5

α 4

3

2 Separation Factor, 1 02468 Time (hr)

Figure 6.1 Separation factor for CO2 relative to CH4 using [bmim][PF6] coated membranes over time

between 1.9 and 2.3, indicating that CO2 was permeating more readily across the membrane. However, this separation factor is lower than the calculated ideal separation factor based on the solubility ratio, which was found to be approximately

34. Since the effects of diffusion were neglected when calculating the ideal factor, it is possible that CH4 has a higher diffusion than CO2, which would result in a lower, actual separation factor. But, it is unlikely that the CH4 diffusion is 17 times greater than the CO2 diffusion and could fully account for the difference. One possible

130 explanation is that the presence of CO2 in the ionic liquid is enhancing the CH4 solubility, a phenomenon that is currently under investigation in our laboratory.

Nonetheless, these experiments do show that separation is occurring due to the IL.

Using the IL-coated membranes to separate the ethylene/ethane mixture yields separation factors ranging between 1.4 and 1.9. The anticipated separation factor, based the on solubility ratio, was 2. So this particular system is behaving ideally.

During the course of all of these experiments, the GC continually detected a peak at the retention time for air. Upon switching to a column capable of separating oxygen and nitrogen, it became apparent that this peak was due to the presence of air in the system. The ratio of nitrogen to oxygen was approximately 4:1, as is the case with air. Possible origins of the air in the system included dissolved air initially in the ionic liquid permeating out, “pockets” of air remaining in the system due to excess volume not in the direct flow path, or the seemingly unlikely possibility that air was diffusing through the plastic membrane holders into the helium on the permeate side due to a concentration gradient. Many attempts were made to eliminate the presence of air, including pulling a vacuum for up to a couple days prior to an experiment, flushing the entire system with helium – both by continuous flow and semi- continuous flow where the system is allowed to sit under helium pressure (no flow) to allow time for “pockets” of air to diffuse into the regular lines, using argon (a heavier gas) rather than helium to flush the system, increasing the pressure on both the permeate and feed side (to discourage diffusion into the system), and encasing the apparatus in a glove bag pressurized with helium. Despite these (and other) efforts, the peak due to air continued to appear. Since no air was present in the feed gas, the

131 selectivities for the CO2/CH4 and C2H4/C2H6 experiments were determined by neglecting the detected air. For obvious reasons, this is more difficult to justify for the CO2/N2 experiments. However, during these experiments, the concentration of nitrogen detected on the permeate side relative to the oxygen was never in excess of the nitrogen to oxygen ratio in air. Therefore, it appears that no nitrogen from the feed gas was permeating across the membrane, which would yield a selectivity of infinity. This selectivity would be consistent with what was expected based on the predicted ideal separation factor of >400, but due to the experimental problems, it is not possible to report this value with confidence. However, these results due suggest that [bmim][PF6] is capable of separating CO2 and N2, as will be confirmed in the following section by the absorber experiments.

6.5 Absorber

The absorber experiments were all conducted at room temperature (22 oC).

Between 12 g and 18 g of [bmim][PF6] was coated on the column of glass beads; the column ranged in height from 8 cm to 23 cm. The pressure drop across the column varied from 0.28 bar to 0.69 bar and the effluent flow rate ranged from 0.5 mL/min to

4 mL/min. Very little difference in absorber performance was observed within these ranges.

The absorber breakthrough curves are shown in Figure 6.2 for CO2 in N2 and

Figure 6.3 for CO2 in CH4. The different curves shown in the figures are runs conducted with slightly different operating conditions (amount of IL, flowrates, inlet pressure), as described above. Initially, no carbon dioxide was detected in the

132 effluent for either mixture, indicating that the IL is successful at removing all the CO2 present in the feed. The CO2 detected in the effluent increases over time until reaching the breakthrough point where the effluent composition is essentially the same as the feed composition. Subsequent runs were conducted after removing the absorbed gases by vacuum so the IL could be reused; no significant difference was observed, as seen by the similarity of the various breakthrough curves shown in

Figure 6.2 and Figure 6.3.

It should be emphasized that these experiments were intended solely as a proof of concept study. The efficiency of gas absorption in conventional absorbers depends strongly on the mass transfer in the system and there are many techniques commonly employed to maximize the mass transfer and contact between the gas and liquid. No attempts were made to optimize the system. However, these experiments do illustrate that it is possible to use [bmim][PF6] to capture CO2 from a gas mixture.

1.2

1.0 Feed

2 0.8

0.6

0.4 Out / CO 2 0.2 CO 0.0 0 20406080100 Time (min) Figure 6.2: Breakthrough curves for the removal of CO2 from N2 using [bmim][PF6] as the absorbent. Different symbols show various runs under slightly different operating conditions, as described in the text.

133 1.2

ed 1.0 Fe

2 0.8

0.6

0.4 Out / CO 2 0.2 CO 0.0 0 20406080100 Time (min) Figure 6.3: Breakthrough curves for the removal of CO2 from CH4 using [bmim][PF6] as the absorbent. Different symbols show various runs under slightly different operating conditions, as described in the text.

6.6 Energy Comparison to Conventional Techniques

6.6.1 Current design using monoethanolamine

The majority of commercial plants that have processes to capture CO2 use a chemical absorption technique with MEA as the solvent.165 Figure 6.4 shows an

168 example of a typical CO2 capture and recovery system. The CO2-rich feed gas is contacted with the solvent in an absorber to produce CO2-lean gas. The CO2-rich solvent is heated in a stripping column to recover the CO2 off-gas and regenerate the solvent.

134 CO2 Off Gas

Condenser Lean Gas Separator Drum Lean Solvent

Condensate Absorber Stripping Trim Column

CO2-Rich Feed Gas Cooler

Rich Solution Interchanger Reboiler

Figure 6.4: Example of a CO2 absorption system using MEA

6.6.2 MEA absorption energy calculations

Using a 25 wt% MEA solution as the solvent in the process shown in Figure 6.4,

Barnicki has reported a detailed calculation for the energy required to capture and

168 recover CO2. He reports the total energy required to be 3.4 million BTU/ton CO2 including the energy required to slightly compress the feed gas to 1.2 bar (0.15 million BTU/ton CO2), to desorb the CO2 in the stripper (2.9 million BTU/ton CO2), and to compress the CO2 off-gas to 100 bar (2 stages, 0.18 million BTU/ton CO2 each).

Here, a simple energy calculation was done to compare the energy usage for CO2 capture by [bmim][PF6] to that by a 30 wt% MEA solution. A simple temperature- swing process was used to mimic the absorber/stripper process in a typical system.

Therefore, energy required for the separation is given by the following equation:

135 Q = −∆habs + m ⋅ Cp ⋅ ∆T (6.10) where Q is the energy needed, ∆habs is the enthalpy of absorption for [bmim][PF6] or the enthalpy of reaction for MEA, m is the mass of solvent, Cp is the heat capacity of the solvent, and ∆T is the temperature difference between the absorption and desorption step. The absorption step was assumed to occur at 25 oC and the desorption step was at 100 oC (approximately the boiling temperature of MEA solutions). The feed gas was chosen to be 1 bar and contain 10% CO2. The partial pressure of CO2 was kept the same for both absorption and desorption stages (PCO2 =

0.1 bar); therefore, the desorption step occurred under vacuum conditions. The heat

169 of reaction for CO2 in a 30 wt% MEA solution is -85.4 kJ/mol. For CO2 in

7 [bmim][PF6], the heat of absorption is -16.1 kJ/mol. The heat capacity for a 30 wt%

MEA in water solution was taken to be that of water (4.18 kJ/kg K). The heat capacity for [bmim][PF6] measured in our laboratory was found to be 397.6 J/mol K at 25 oC and 405.1 J/mol K at 50 oC.18 The small effect of temperature on the heat capacity was found to be negligible in the calculations and therefore neglected; the value at 25 oC was used.18

The results of these calculations are shown in Table 6.2. The energy calculated using MEA as the absorbent is 6.1 million BTU/ton CO2, which is about a factor of two larger than the energy found by Barnicki’s rigorous energy calculation. This difference is most likely due to the simple one-stage desorption step used here as opposed to the multi-stage stripping column used by Barnicki, but the number is consistent enough to justify comparing these calculated MEA and [bmim][PF6] energy requirements. For a CO2 partial pressure of 0.1 bar, the energy required for

136

TABLE 6.2:

ENERGY CALCULATION RESULTS FOR CO2 ABSORPTION AND

RECOVERY BY TEMPERATURE-SWING (25 OC TO 100 OC) USING

[bmim][PF6] OR 30 WT% MEA SOLUTION

(CO2 PARTIAL PRESSURE = 0.1 BAR)

[bmim][PF6] MEA (30 wt%) mass solvent/kg CO2 5914 17 ∆habs or ∆hrxn (kJ/kg CO2) -366 -1932 Cp (kJ/kg K) 1.40 4.18 5 3 Q (kJ/kg CO2) 6.2 x 10 7.1 x 10 4 2 Q (kJ/mol CO2) 2.7 x 10 3.1 x 10 Q (million BTU/ton CO2) 534 6.1

the [bmim][PF6] process is significantly larger than that for the MEA process; between 60 and 150 times more energy is needed per ton of CO2 recovered. This difference is due to the smaller CO2 carrying capacity of [bmim][PF6] relative to the

MEA solution, which results in 350 times more ionic liquid being needed than MEA solution per kilogram of CO2 desorbed.

The CO2 solubility in [bmim][PF6], and therefore the IL carrying capacity, is

7 strongly dependent on the partial pressure of CO2. Table 6.3 and Table 6.4 show results from repeating the calculations with a CO2 partial pressure of 1 bar and 2 bar, respectively. Increasing the CO2 pressure from 0.1 bar to 1 bar decreases the energy usage in [bmim][PF6] by an order of magnitude, whereas it does not have any effect on the MEA energy requirement. Obviously, increasing the pressure even more, up

137 TABLE 6.3:

ENERGY CALCULATION RESULTS FOR CO2 ABSORPTION AND

RECOVERY BY TEMPERATURE-SWING (25 OC TO 100 OC) USING

[bmim][PF6] OR 30 WT% MEA SOLUTION

(CO2 PARTIAL PRESSURE = 1 BAR).

[bmim][PF6] MEA (30 wt%) mass solvent/kg CO2 535 19 ∆habs or ∆hrxn (kJ/kg CO2) -366 -1932 Cp (kJ/kg K) 1.40 4.18 4 3 Q (kJ/kg CO2) 5.7 x 10 7.7 x 10 3 2 Q (kJ/mol CO2) 2.5 x 10 3.4 x 10 Q (million BTU/ton CO2) 49 6.7

TABLE 6.4:

ENERGY CALCULATION RESULTS FOR CO2 ABSORPTION AND

RECOVERY BY TEMPERATURE-SWING (25 OC TO 100 OC) USING

[bmim][PF6] OR 30 WT% MEA SOLUTION

(CO2 PARTIAL PRESSURE = 2 BAR)

[bmim][PF6] MEA (30 wt%) mass solvent/kg CO2 255 20 ∆habs or ∆hrxn (kJ/kg CO2) -366 -1932 Cp (kJ/kg K) 1.40 4.18 4 3 Q (kJ/kg CO2) 2.7 x 10 8.2 x 10 3 2 Q (kJ/mol CO2) 1.2 x 10 3.6 x 10 Q (million BTU/ton CO2) 23 7.1

138 to 2 bar, decreases the energy usage in [bmim][PF6] even further; again there is no difference for the MEA calculation. As found by Barnicki’s calculations, the energy required for compressing gas (0.36 million BTU/ton CO2 to compress CO2 from 1 bar to 100 bar) is much smaller than the energy required for the desorption step in the stripper.168 In fact, physical absorption processes often employ a pressure-swing system rather than a temperature-swing system. Since there is no heat of reaction to overcome with a physical absorbent such as [bmim][PF6], it would not be necessary to operate over such a large temperature range, decreasing the energy requirements significantly. There is likely an optimal design combining pressure-swing and temperature-swing operations. Obviously, any design would also have capital costs associated with it, but that analysis is beyond the scope of this work. Here the focus only is on the operating costs in terms of energy usage.

6.7 Alternative Ionic Liquid Options

6.7.1 Ideal carrying capacities

Based on these energy calculations, [bmim][PF6] will not be a realistic replacement for MEA using a conventional temperature-swing recovery system.

However, MEA has been optimized as a CO2 capture solvent, whereas [bmim][PF6] was chosen for this analysis simply because it is a common IL. It has been studied most extensively as a solvent for reactions, not as a medium for gas separations. To make ionic liquids competitive replacements for MEA-based technologies, the CO2 carrying capacity needs to be increased. Table 6.5 lists Henry’s constants for a

“theoretical” IL with the same Cp and ∆habs as [bmim][PF6] that would result in

139 comparable energy requirements to MEA using the same temperature-swing process.

Ionic liquids having Henry’s constants less than 1 bar at 25 oC (or up to about 20 bar if exposed to a higher CO2 pressure) would provide reasonable carrying capacities for

CO2 capture, and thus should be competitive with current amine solvents.

TABLE 6.5:

PARAMETERS FOR THEORETICAL IL THAT WOULD BE COMPETITIVE

WITH MEA USING TEMPERATURE-SWING (25 OC TO 100 OC) ABSORPTION

AND RECOVERY (GIVES Q = 6.1 MILLION BTU/TON CO2)

PCO2 = 0.1 bar PCO2 = 1 bar PCO2 = 2 bar mass solvent/kg CO2 64 70 75 H (bar) at 25 oC 0.8 9 19 H (bar) at 100 oC 3 34 72

6.7.2 Ionic liquid design

There are many ways to increase CO2 solubility in ionic liquids by adjusting the anion or the cation. In our lab, we have found that changing the anion from [PF6] to

[Tf2N] doubles the CO2 solubility. Davis and coworkers developed a “task-specific ionic liquid” by adding an amine group to the alkyl chain on the imidazolium ring.

They report CO2 carrying capacities equivalent to those seen in MEA. Although not

63 reported, the ∆hrxn is very likely to be the same as with the MEA solution. Baltus and coworkers attached a long fluorinated alkyl chain to the cation,

115 [C8F13mim][Tf2N], and measured a Henry’s constant of about 4.5 bar. This IL would probably still be a physical absorbent. Unfortunately, both groups also report that their ILs are extremely viscous. Nonetheless, there is a great potential to develop

140 an ionic liquid that is competitive with MEA in terms of CO2 carrying capacity and energy requirements, but that also has the added advantage of negligible vapor pressure.

6.8 Summary

Ionic liquids have been shown to have use as a gas separations medium. In particular, [bmim][PF6] is successful in capturing CO2 from a N2 or CH4 mixture.

C2H4 and C2H6 can also be separated using [bmim][PF6]. The supported ionic liquid membrane system was found to be stable over the course of the experiments (on the order of weeks). In the absorber setup, the CO2 can be recovered fairly easily by either increasing the temperature or decreasing the pressure, since CO2 is physically absorbed by the IL. Although [bmim][PF6] does not have the necessary CO2 carrying capacity to be a viable competitor with MEA, this is not surprising because it was not designed with the intention of using it for CO2 capture. Developing an ionic liquid with a carrying capacity that will make ILs competitive with MEA for CO2 capture should be a realistic possibility. Their lack of volatility gives ionic liquids the unique feature that they can perform clean gas separations without any loss of solvent or contamination of the gas stream.

141

CHAPTER 7

CONCLUSIONS AND RECOMMENDATIONS

7.1 Conclusions

The solubilities of a variety of gases in several different ionic liquids have been reported. Water and benzene were most soluble, followed by nitrous oxide and carbon dioxide, then ethylene, ethane, methane and oxygen and argon for the ionic liquids considered. Hydrogen, carbon monoxide, and nitrogen were all below the solubility limit of the apparatus. Gases with large dipole moments (e.g. water) or quadrapole moments (e.g. CO2 and N2O) have the highest solubilities in the ionic liquids, whereas the solubilities of the other non-polar gases correlate well with their polarizability. However, carbon monoxide and nitrogen solubilities do not follow these trends, indicating that dipole and quadrapole moments and polarizability cannot fully describe the behavior of the gases in the ILs. The anion appears to play the most significant role in determining the gas solubilities. The [Tf2N] anion increases all gas solubilities relative to [BF4] and [PF6] ILs, whereas the [BF4] anion has little effect on the solubility of the gases relative to [PF6]. However, [BF4] does significantly increase water solubility in the ionic liquid relative to ILs with the [PF6] anion. The nature of the cation has more subtle influences on both water and carbon dioxide solubility. Replacing the hydrogen with a methyl group at the 2-positon on the

142 imidazolium ring slightly decreases the solubility of carbon dioxide. Changing the cation from imidazolium to quaternary ammonium to pyrrolidinium, all with the

[Tf2N] anion, made little difference in the CO2 solubility. A longer alkyl chain on an imidazolium cation decreases the water solubility. Liquid-liquid equilibrium results were consistent with the vapor solubility results and also showed that a significant amount of IL dissolves in water. This cross-contamination between ionic liquid and aqueous phases will very likely cause separation concerns if ionic liquids are to be incorporated into an industrial process.

Ionic liquids proved to have potential as a gas separations medium. The IL

[bmim][PF6] separated CO2 from either a N2 or CH4 mixture and C2H4 from a mixture with C2H6. Both the supported ionic liquid membrane system and the absorber system yielded consistent results. The supported ionic liquid membranes were found to be stable over the course of the experiments. Recovery of the CO2 or C2H4 from the IL in the absorber was accomplished easily by either increasing the temperature or decreasing the pressure. Although the simple energy calculations confirm that

[bmim][PF6] will not be a viable competitor with MEA due to its smaller CO2 carrying capacity, this is not surprising because it was not designed with the intention of using it for CO2 capture. Developing an ionic liquid with a carrying capacity that will make ILs competitive with MEA for CO2 capture should be a realistic possibility.

Their lack of volatility gives ionic liquids the unique feature that they can perform clean gas separations without any loss of solvent or contamination of the gas stream.

143 7.2 Recommendations

The influence of cation and anion structure on gases other than carbon dioxide needs to be investigated more in depth. This work addressed the solubilities of a series of gases in three ionic liquids with different anions, but primarily carbon dioxide solubility was investigated in ionic liquids with different cations. Although

CO2 solubility is governed most prominently by the anion and didn’t change significantly with different cations, that is not necessarily the case for the other gases.

For example, cations such as ammonium and phosphinium with the long alkyl chains could result in larger hydrocarbon solubilities.

Gas solubilities in non-fluorinated anions also need to be studied, since fluorinated compounds are generally considered to be a higher risk to the environment. Ionic liquids with anions such as bis(methylsulfonyl) imide

- - - [(CH3SO2)2N] , acetate [CH3CO2] , or nitrate [NO3] could have reduced consequences if released into the environment, therefore making them a more attractive choice, as long as they also have the desired physical and mixture properties.

The influence adding functional groups to either the cation or the anion has on gas solubilities should also be studied. For example, perhaps adding an alkyl chain with a double bond to the cation could be used to increase the ethylene versus ethane solubility. The development of any new ionic ionic liquid would also require investigations of the other physical properties (e.g. melting point, viscosity, density, etc.).

144 Before ionic liquids could realistically be use for gas separations, there are several other issues that would need to be addressed, specifically measuring the diffusion of gases into the ionic liquids and the solubility of gas mixtures in the ionic liquids.

These issues are currently being investigated in our laboratory. In addition to these studies, attempts should be made to exploit the opportunity to “tailor” the properties of the ILs by changing cations and anions and design an ionic liquid specific for a desired gas separation. An ideal separating agent will high carrying capacity for the relevant gas to minimize the amount of solvent need, a low heat of absorption/reaction and/or heat capacity to minimize the energy needed to recover the gas, and a low viscosity to increase mass transfer/diffusivity and to minimize any associated pumping costs. For the specific case of capturing CO2, others have shown that adding a fluorinate alkyl chain or an amine group to an imidazolium cation significantly increases the CO2 carrying capacity but also increases the viscosity.

There is likely an optimal structure that can increase this carrying capacity without significantly increasing the viscosity.

Addition of facilitating agents to the ionic liquids to enhance the solubility of one compound relative to another, such as silver to enhance olefin solubilities relative to paraffins, should also be investigated. Again, regarding CO2 capture by ionic liquids, it might be possible to add facilitators, such as MEA, to the ionic liquid to further increase the CO2 solubility while still taking advantage of the non-volatile and wide liquidus range of the ionic liquid.

In addition to developing an ionic liquid with an improved CO2 carrying capacity, a more in-depth process simulation should be done to truly evaluate using ionic

145 liquids as potential CO2 capturing agents compared to MEA. Specifically, this simulation should consider pumping costs and any capital costs associated with the use of ILs. Such a simulation could also be used to determine the “optimal” properties of an ideal ionic liquid (i.e. what viscosity, gas-carrying capacity, and heat capacity would yield a competitive solvent).

146

APPENDIX A

CALIBRATION CURVES FOR ICP-OES MEASUREMENTS

This appendix includes the calibration curves for silver and for phosphorous in water using an inductively coupled plasma optically emitting spectrometer.

2500000 243.778 nm: Conc (wt% Ag) = 1.29 x 10-7 x Peak Intensity + 3.67 x 10-4 2000000

1500000

1000000 Peak Intensity 224.874 nm: Conc (wt% Ag) = -7 --3 500000 9.44 x 10 x Peak Intensity + 1.21 x 10

0 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 Concentration (wt%)

Figure A-1 Calibration for silver in water

147

500000 213.617 nm Conc (ppm P) = (2.17 x 10-4) x Peak Intensity + 0.402 400000

300000

200000 Peak Intensity

100000

214.914 nm Conc (ppm P) = (4.96 x 10-4) x Peak Intensity + 0.778 0 0 1020304050607080 Concentration (mg/L)

Figure A-2 Calibration for phosphorous in water

148

APPENDIX B

ERROR ANALYSIS FOR HENRY’S CONSTANTS

The following figure gives an example of the process used to determine the error for the Henry’s constants. The absorption points are shown by the solid symbols and

0.014

0.012 y = 8.16E-04x y = 7.13E-04x

s 2 2

a R = 9.19E-01 R = 8.58E-01 0.010 G

0.008 on of i t ac

r 0.006 F e l

o 0.004 M 0.002

0.000 0 2 4 6 8 10 12 14 16 Pressure (bar)

Figure B-1 Determining the Henry’s constant for CH4 in [bmim][PF6]

the desorption are the open symbols. The solid lines are linear fits to the data

(absorption and desorption separately). The inverse slopes of the lines are the

Henry’s constants for the two isotherms; the average of which is taken to be the actual Henry’s constant. The dashed lines represent the error in the Henry’s

149 constants. These lines are determined by choosing some fraction to increase and

decrease the averaged slope from the absorption and desorption data (i.e. average

Henry’s constant) so that the normalized deviation of the data from this range is less

than 10%. The following paragraph explains how this normalized deviation is

determined.

Averaging the linear fits of the absorption and desorption data gives the equation

 1  x =   ⋅ P (B-1)    H average 

The equations for the upper and lower bounds of the error are given by

 1   1  x = 1− f ⋅   ⋅ P and x = 1+ f ⋅   ⋅ P (B-2) low ()  high ()   H average   H average 

where f is the fraction the slope is decreased or increased to yield the desired

normalized deviation. If xlow − xactual > 0 , where xactual is the measured mole

fraction, then the actual value is below the lower limit, and if xhigh − xactual < 0 then

the actual value is above the upper limit. The total deviation is determined by

summing the mole fractions that fall outside the range and averaged over the number

of data points. The values of the mole fractions are used for the deviation to give

stronger weight to the larger values, since there is more error associated with the low

solubility measurements. The average deviation is normalized by the midpoint of the

data set to obtain the normalized deviation. The table on the following page gives a

sample of these calculations for the data shown in Figure B-1. The average Henry’s

constant was 1314 bar. A factor of 0.21 was found to give a normalized deviation of

0.5%. The final error was 289 bar.

150

TABLE B-2

O SAMPLE ERROR CALCULATIONS FOR CH4 IN [bmim][PF6] AT 50 C

limiting number slope H (H - avg H)^2 H's average sigma 50 °C Abs 8.16E-04 1225.49 7835.290 2 1314.0 125.2 Des 7.13E-04 1402.52 7835.290 Fraction: 0.21 1663.3 Error: 288.7 1086.0

P (bar) X Low Low - X Below Range? High High - X Above Range? 0.00 0 0 0 0 0 0 0 0.01 -2.05E-04 8.18E-06 2.13E-04 2.13E-04 1.25E-05 2.17E-04 0 0.05 -1.63E-04 3.13E-05 1.94E-04 1.94E-04 4.79E-05 2.11E-04 0 0.21 -3.99E-05 1.23E-04 1.63E-04 1.63E-04 1.89E-04 2.29E-04 0 0.60 2.69E-04 3.62E-04 9.22E-05 9.22E-05 5.54E-04 2.84E-04 0 1.00 5.17E-04 6.03E-04 8.61E-05 8.61E-05 9.23E-04 4.07E-04 0 2.00 1.13E-03 1.20E-03 7.48E-05 7.48E-05 1.84E-03 7.15E-04 0 3.00 3.04E-03 1.80E-03 -1.24E-03 0 2.76E-03 -2.77E-04 -2.77E-04 4.00 4.25E-03 2.41E-03 -1.85E-03 0 3.69E-03 -5.70E-04 -5.70E-04 5.00 4.25E-03 3.01E-03 -1.25E-03 0 4.61E-03 3.53E-04 0 6.00 4.50E-03 3.61E-03 -8.95E-04 0 5.53E-03 1.02E-03 0 7.00 4.48E-03 4.21E-03 -2.70E-04 0 6.45E-03 1.97E-03 0 8.00 8.91E-03 4.81E-03 -4.10E-03 0 7.37E-03 -1.54E-03 -1.54E-03 9.00 6.33E-03 5.41E-03 -9.20E-04 0 8.29E-03 1.96E-03 0 10.00 1.01E-02 6.01E-03 -4.10E-03 0 9.21E-03 -9.06E-04 -9.06E-04 11.00 1.02E-02 6.61E-03 -3.54E-03 0 1.01E-02 -2.60E-05 -2.60E-05 12.00 7.72E-03 7.22E-03 -5.04E-04 0 1.11E-02 3.33E-03 0 13.00 9.73E-03 7.82E-03 -1.92E-03 0 1.20E-02 2.24E-03 0 13.00 9.85E-03 7.82E-03 -2.04E-03 0 1.20E-02 2.12E-03 0 12.50 1.14E-02 7.52E-03 -3.90E-03 0 1.15E-02 1.01E-04 0 11.50 8.72E-03 6.91E-03 -1.81E-03 0 1.06E-02 1.87E-03 0 10.50 8.53E-03 6.31E-03 -2.22E-03 0 9.67E-03 1.14E-03 0 9.50 7.47E-03 5.71E-03 -1.76E-03 0 8.75E-03 1.28E-03 0 8.50 7.58E-03 5.11E-03 -2.47E-03 0 7.83E-03 2.46E-04 0 7.50 7.58E-03 4.51E-03 -3.07E-03 0 6.91E-03 -6.77E-04 -6.77E-04 6.50 5.99E-03 3.91E-03 -2.08E-03 0 5.99E-03 -2.84E-06 -2.84E-06 5.50 1.70E-03 3.31E-03 1.60E-03 1.60E-03 5.06E-03 3.36E-03 0 4.50 2.75E-03 2.71E-03 -4.63E-05 0 4.15E-03 1.39E-03 0 3.50 -5.36E-04 2.10E-03 2.64E-03 2.64E-03 3.22E-03 3.76E-03 0 2.50 1.74E-03 1.50E-03 -2.37E-04 0 2.30E-03 5.62E-04 0 1.50 4.92E-04 9.01E-04 4.09E-04 4.09E-04 1.38E-03 8.89E-04 0 0.50 1.24E-04 3.00E-04 1.76E-04 1.76E-04 4.60E-04 3.35E-04 0 0.10 -2.15E-04 5.93E-05 2.75E-04 2.75E-04 9.08E-05 3.06E-04 0 Sum of Deviation Below 5.93E-03 Above -4.00E-03 Total Deviation (Absolute Value) 9.92E-03 Average Deviation 3.01E-04 Midpoint 5.97E-03 Normalized Deviation 0.050

151

APPENDIX C

CALIBRATION CURVES FOR UV-VISIBLE SPECTROSCOPY

MEASUREMENTS

This appendix contains the calibration curves for [bmim][PF6], [C8mim][PF6], and

[C8mim][BF4] in water using a UV-visible spectrometer.

1.8 1.6

1.4 Abs = (4.80 x 106) x c 1.2

1.0

0.8

0.6

Absorbance at 211 nm 0.4

0.2

0.0 8 7 -7 0.0 e- .0e- .0e-7 .5e-7 .0 .5e-7 .0e-7 .5e 5 1 1 2 2 3 3

2 c (mol/cm )

Figure C-1 Calibration for [bmim][PF6] in water

152

1.6

1.4

6 1.2 Abs = (4.19 x 10 ) x c

1.0

0.8

0.6

Absorbance at 211 nm 0.4

0.2

0.0 -8 7 7 7 0.0 5.0e 1.0e- 1.5e- 2.0e- 2.5e-7 3.0e-7 3.5e-7

2 c (mol/cm )

Figure C-2 Calibration for [C8mim][PF6] in water

153

1.6

1.4 Abs = (4.17 x 106) x c 1.2

1.0

0.8

0.6

Absorbance at 211 nm 0.4

0.2

0.0 0 8 7 7 7 0. e- 0e- 5e-7 0e- 5e- 5. 1.0 1.5e-7 2.0e-7 2. 3. 3.

c (mol/cm2)

Figure C-3 Calibration for [C8mim][BF4] in water

154

APPENDIX D

RAW DATA FOR GAS SOLUBILITY MEASUREMENTS USING THE

GRAVIMETRIC MICROBALANCE

This appendix includes the raw data for all the experiments conducted using the gravimetric microbalance and presented in Chapters 4 and 5. The tables are organized alphabetically by gas and then ionic liquid. Each table lists mass reading

(before buoyancy correction), the temperature reading, and the pressure reading from the balance. The bulk gas densities, as calculated using the equation of state mentioned in Chapter 3, and the mole fraction and weight percent of gas in the IL after correcting for buoyancy are listed as well. Each table also lists the equilibration time used, the source of the sample, and the sample bucket used. All experiments were conducted using the static gas or static vapor (for benzene and water) unless otherwise specified. Readings of negative weight percents (and corresponding negative mole fractions) are obviously not physically possible and are within the resolution of the balance. Negative values are thus equivalent to zero, but are reported here because they were included in the fitting procedure for the Henry’s constants.

155 TABLE D-1 ARGON IN [bmim][PF6]

10 oC 90 min Sachem SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction (mg) (oC) (bar) (g / cm3) of Gas Wt % Gas 76.74447 16.597 0 3.21E-292 1.27E-291 1.79E-290 76.74158 10.126 0.0075 1.27E-05 -2.17E-04 -3.06E-03 76.7389 10.079 0.0491 8.33E-05 -1.86E-04 -2.61E-03 76.72878 10.088 0.1975 3.35E-04 -1.24E-04 -1.74E-03 76.7007 10.079 0.5985 1.02E-03 -2.29E-05 -3.21E-04 76.67096 10.077 0.9998 1.70E-03 -7.23E-05 -1.02E-03 76.59807 10.088 1.9968 3.39E-03 -9.59E-05 -1.35E-03 76.5258 10.079 2.9996 5.10E-03 -1.12E-05 -1.58E-04 76.45353 10.079 3.9989 6.81E-03 6.00E-05 8.44E-04 76.38023 10.084 4.9995 8.51E-03 5.46E-05 7.68E-04 76.30858 10.091 5.999 1.02E-02 2.05E-04 2.88E-03 76.23589 10.079 6.9976 1.19E-02 2.66E-04 3.74E-03 76.16403 10.084 7.9974 1.37E-02 4.19E-04 5.90E-03 76.09074 10.079 8.9977 1.54E-02 4.57E-04 6.42E-03 76.01516 10.075 9.9986 1.71E-02 2.96E-04 4.17E-03 75.94392 10.079 10.9978 1.88E-02 5.35E-04 7.52E-03 75.87206 10.088 11.9984 2.05E-02 7.34E-04 1.03E-02 75.79835 10.079 12.9988 2.23E-02 7.76E-04 1.09E-02 75.79835 10.095 12.9999 2.23E-02 7.78E-04 1.09E-02 75.83469 10.075 12.4988 2.14E-02 7.10E-04 9.98E-03 75.90903 10.077 11.4984 1.97E-02 7.33E-04 1.03E-02

156 TABLE D-1 ARGON IN [bmim][PF6] (cont.)

25 oC 90 min Sachem SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density (g Fraction (mg) (oC) (bar) / cm3) of Gas Wt % Gas 76.74323 25.077 0 3.21E-292 1.29E-291 1.81E-290 76.73911 25.055 0.0106 1.71E-05 -3.13E-04 -4.40E-03 76.73683 25.073 0.0488 7.86E-05 -2.77E-04 -3.90E-03 76.72733 25.077 0.1963 3.16E-04 -2.03E-04 -2.86E-03 76.70111 25.073 0.5964 9.61E-04 -4.29E-05 -6.03E-04 76.67385 25.079 0.9969 1.61E-03 2.47E-05 3.48E-04 76.60571 25.066 1.9984 3.22E-03 2.03E-04 2.85E-03 76.53923 25.07 2.9976 4.84E-03 5.27E-04 7.41E-03 76.47232 25.07 3.9966 6.45E-03 8.18E-04 1.15E-02 76.40562 25.073 4.997 8.08E-03 1.15E-03 1.61E-02 76.33563 25.073 5.9968 9.70E-03 1.17E-03 1.65E-02 76.26563 25.084 6.999 1.13E-02 1.22E-03 1.72E-02 76.19521 25.077 7.998 1.29E-02 1.22E-03 1.72E-02 76.12728 25.081 8.9975 1.46E-02 1.46E-03 2.05E-02 76.05996 25.07 9.9981 1.62E-02 1.77E-03 2.49E-02 75.98522 25.077 10.9991 1.78E-02 1.40E-03 1.97E-02 75.91377 25.073 11.9993 1.95E-02 1.34E-03 1.89E-02 75.84749 25.075 12.9979 2.11E-02 1.76E-03 2.48E-02 75.84749 25.086 12.9976 2.11E-02 1.76E-03 2.47E-02 75.87763 25.07 12.4989 2.03E-02 1.28E-03 1.80E-02 75.94743 25.073 11.4987 1.87E-02 1.18E-03 1.66E-02 76.01598 25.079 10.4985 1.70E-02 9.72E-04 1.37E-02 76.08639 25.066 9.499 1.54E-02 9.54E-04 1.34E-02 76.15763 25.07 8.4974 1.38E-02 1.00E-03 1.41E-02 76.2264 25.075 7.4993 1.21E-02 8.53E-04 1.20E-02 76.29598 25.073 6.4973 1.05E-02 7.62E-04 1.07E-02 76.36453 25.086 5.4972 8.89E-03 5.94E-04 8.36E-03 76.43288 25.077 4.4972 7.27E-03 4.19E-04 5.90E-03 76.50227 25.068 3.4965 5.65E-03 3.43E-04 4.83E-03 76.56958 25.079 2.4988 4.03E-03 1.01E-04 1.42E-03 76.63648 25.077 1.4968 2.41E-03 -1.99E-04 -2.80E-03 76.704 25.07 0.4983 8.03E-04 -4.11E-04 -5.77E-03 76.72961 25.07 0.0954 1.54E-04 -6.45E-04 -9.07E-03 76.7389 26.177 0.0042 6.74E-06 -3.74E-04 -5.26E-03

157 TABLE D-1 ARGON IN [bmim][PF6] (cont.)

50 oC 90 min Sachem SS bucket

Mass Sample Sample Mole Reading Temperature Pressure Gas Density Fraction (mg) (oC) (bar) (g / cm3) of Gas Wt % Gas 76.73621 50.09 0.0001 1.49E-06 6.09E-06 8.56E-05 76.73579 50.008 0.0109 1.62E-05 2.74E-05 3.86E-04 76.73476 50.019 0.049 7.29E-05 1.64E-04 2.30E-03 76.72671 50.017 0.1968 2.93E-04 3.17E-04 4.46E-03 76.70152 50.019 0.5987 8.90E-04 4.30E-04 6.04E-03 76.6753 50.013 0.9967 1.48E-03 4.24E-04 5.96E-03 76.61665 50.015 1.9993 2.97E-03 1.10E-03 1.54E-02 76.57681 50.004 2.9991 4.46E-03 3.49E-03 4.92E-02 76.51052 50.002 3.9986 5.95E-03 3.45E-03 4.86E-02 76.42916 50.024 4.9979 7.45E-03 2.02E-03 2.84E-02 76.38911 50.01 5.9994 8.94E-03 4.42E-03 6.23E-02 76.341 50 6.9989 1.04E-02 6.06E-03 8.56E-02 76.28132 50.022 7.9982 1.19E-02 6.63E-03 9.38E-02 76.21091 50.013 8.9981 1.34E-02 6.24E-03 8.82E-02 76.15537 50.017 9.9991 1.49E-02 7.22E-03 1.02E-01

TABLE D-2 BENZENE IN [bmim][BF4]

10 oC 180 min Welton SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction Wt % (mg) (oC) (bar) P / Psat (g / cm3) of Gas Gas 75.74796 13.573 0.00006 0.0009836 1.97E-07 3.72E-07 1.28E-05 75.78859 10.091 0.00053 0.0086885 1.76E-06 1.55E-03 5.37E-02 75.87231 10.084 0.00113 0.0185246 3.75E-06 4.74E-03 0.16 76.40533 10.084 0.00518 0.084918 1.72E-05 2.45E-02 0.86 77.29943 10.077 0.01015 0.1663934 3.37E-05 5.60E-02 2.01 78.45499 10.099 0.01503 0.2463934 4.99E-05 9.38E-02 3.45 82.7842 10.071 0.0301 0.4934426 9.99E-05 2.12E-01 8.50 95.51862 10.079 0.05006 0.8206557 1.66E-04 4.30E-01 20.7 95.52356 10.075 0.05006 0.8206557 1.66E-04 4.30E-01 20.7 89.96828 10.088 0.04005 0.6565574 1.33E-04 3.52E-01 15.8 81.48574 10.071 0.01998 0.327541 6.63E-05 1.80E-01 7.05 77.1955 10.086 0.00308 0.0504918 1.02E-05 5.24E-02 1.88 76.13501 10.071 0.00008 0.0013115 2.65E-07 1.46E-02 0.51

158 TABLE D-2 BENZENE IN [bmim][BF4] (cont.)

25 oC 180 min Welton SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction Wt % (mg) (oC) (bar) P / Psat (g / cm3) of Gas Gas 75.73579 25.026 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 75.75291 25.075 5.90E-04 4.68E-03 1.86E-06 6.57E-04 2.27E-02 75.79189 25.077 1.14E-03 9.05E-03 3.59E-06 2.15E-03 7.43E-02 76.04283 25.073 5.19E-03 4.12E-02 1.64E-05 1.16E-02 0.40 76.42534 25.077 9.85E-03 7.82E-02 3.10E-05 2.57E-02 0.90 76.91466 25.075 1.48E-02 1.18E-01 4.67E-05 4.32E-02 1.54 78.4688 25.077 2.99E-02 2.37E-01 9.41E-05 9.47E-02 3.49 81.25913 25.09 5.01E-02 3.98E-01 1.58E-04 1.74E-01 6.81 84.90891 25.081 6.98E-02 5.54E-01 2.20E-04 2.60E-01 10.8 91.69812 25.066 9.50E-02 7.54E-01 2.99E-04 3.79E-01 17.4 91.69873 25.075 9.50E-02 7.54E-01 2.99E-04 3.79E-01 17.4 89.02449 25.07 8.48E-02 6.73E-01 2.67E-04 3.37E-01 14.9 83.51044 25.079 5.97E-02 4.74E-01 1.88E-04 2.29E-01 9.32 78.51746 25.068 2.49E-02 1.98E-01 7.86E-05 9.62E-02 3.55 76.82433 25.079 9.91E-03 7.87E-02 3.12E-05 4.00E-02 1.42 76.1781 25.079 3.78E-03 3.00E-02 1.19E-05 1.66E-02 0.58

25 oC 90 min Welton SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction (mg) (oC) (bar) P / Psat (g / cm3) of Gas Wt % Gas 75.76838 25.048 1.96E-05 0.000156 6.18E-08 1.18E-07 4.07E-06 75.7655 25.035 5.45E-05 0.000433 1.72E-07 -1.10E-04 -3.79E-03 75.81499 25.07 0.001006 0.007982 3.17E-06 1.78E-03 6.17E-02 76.08964 25.068 0.005002 0.039699 1.58E-05 1.22E-02 0.42 76.50699 25.07 0.010009 0.079436 3.15E-05 2.75E-02 0.97 77.0023 25.079 0.014985 0.118925 4.72E-05 4.51E-02 1.61 77.55182 25.066 0.019993 0.158671 6.30E-05 6.39E-02 2.30 78.61314 25.084 0.030001 0.238106 9.45E-05 9.81E-02 3.62 81.12386 25.095 0.049998 0.396807 1.58E-04 1.70E-01 6.61E 84.83323 25.077 0.069995 0.555517 2.21E-04 2.57E-01 10.7

159 TABLE D-2 BENZENE IN [bmim][BF4] (cont.)

40 oC 180 min Welton SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction Wt % (mg) (oC) (bar) P / Psat (g / cm3) of Gas Gas 75.7459 39.911 5.00E-05 4.96E-06 1.19E-07 2.89E-07 1.00E-05 75.75373 39.942 6.20E-04 6.16E-05 1.47E-06 3.03E-04 1.05E-02 75.77642 39.942 1.15E-03 1.14E-04 2.73E-06 1.17E-03 4.05E-02 75.9521 39.94 5.22E-03 5.18E-04 1.24E-05 7.85E-03 0.27 76.1882 39.933 1.02E-02 1.01E-03 2.41E-05 1.67E-02 0.58 76.44348 39.931 1.51E-02 1.50E-03 3.59E-05 2.60E-02 0.92 77.24168 39.928 3.01E-02 2.99E-03 7.15E-05 5.42E-02 1.94 79.03194 39.942 6.00E-02 5.95E-03 1.42E-04 1.12E-01 4.17 79.03214 39.933 6.00E-02 5.96E-03 1.42E-04 1.12E-01 4.17 78.50468 39.944 5.01E-02 4.97E-03 1.19E-04 9.56E-02 3.52 76.79299 39.944 2.01E-02 1.99E-03 4.76E-05 3.86E-02 1.37 76.26842 39.942 1.02E-02 1.01E-03 2.41E-05 1.96E-02 0.69 75.96282 39.942 4.12E-03 4.09E-04 9.78E-06 8.24E-03 0.29 75.75951 39.944 2.30E-04 2.28E-05 5.46E-07 5.21E-04 1.80E-02

50 oC 180 min Welton SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction Wt % (mg) (oC) (bar) P / Psat (g / cm3) of Gas Gas 75.74033 50.065 1.00E-05 2.76E-05 2.91E-08 5.64E-08 1.95E-06 75.79622 49.995 2.92E-03 8.07E-03 8.49E-06 2.15E-03 7.43E-02 75.81786 50.017 3.45E-03 9.53E-03 1.00E-05 2.97E-03 0.10 75.93602 50.017 7.50E-03 2.07E-02 2.18E-05 7.46E-03 0.26 76.0946 50.015 1.25E-02 3.45E-02 3.63E-05 1.34E-02 0.47 76.26182 50.022 1.74E-02 4.80E-02 5.05E-05 1.96E-02 0.69 76.43256 50.010 2.23E-02 6.15E-02 6.48E-05 2.59E-02 0.91 76.77217 50.019 3.24E-02 8.96E-02 9.43E-05 3.81E-02 1.35 77.47635 50.002 5.24E-02 1.45E-01 1.52E-04 6.25E-02 2.25 78.26858 50.013 7.24E-02 2.00E-01 2.10E-04 8.84E-02 3.24 79.53527 50.006 1.02E-01 2.82E-01 2.97E-04 1.27E-01 4.79 81.50554 50.000 1.42E-01 3.94E-01 4.14E-04 1.81E-01 7.10 85.16914 50.002 2.02E-01 5.58E-01 5.88E-04 2.65E-01 11.10

160 TABLE D-3 CARBON DIOXIDE IN [bmim][BF4]

10 oC 90 min Welton SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 75.8486 17.795 -0.001 3.2E-292 1.08E-291 2.10E-290 75.84529 10.091 0.0066 1.23E-05 -1.83E-04 -3.56E-03 75.84735 10.082 0.0481 9.00E-05 2.17E-04 4.23E-03 75.88303 10.082 0.1967 3.68E-04 0.004 0.07 75.98138 10.095 0.5971 1.12E-03 0.013 0.25 76.09252 10.077 0.9988 1.88E-03 0.022 0.44 76.34409 10.079 1.9979 3.78E-03 0.044 0.89 76.61773 10.079 2.9983 5.71E-03 0.067 1.37 76.8994 10.075 3.9982 7.66E-03 0.088 1.85 77.18147 10.075 4.9966 9.63E-03 0.109 2.33 77.46171 10.079 5.9981 1.16E-02 0.129 2.81 77.7442 10.082 6.9993 1.37E-02 0.148 3.28 78.02629 10.073 7.9973 1.57E-02 0.167 3.75 78.3059 10.079 8.9991 1.78E-02 0.184 4.22 78.58449 10.075 9.9985 1.99E-02 0.201 4.68 78.85955 10.093 10.9993 2.21E-02 0.218 5.13 79.14761 10.075 11.999 2.43E-02 0.234 5.60 79.42022 10.099 12.9984 2.65E-02 0.249 6.05 79.42043 10.057 12.997 2.65E-02 0.249 6.05 79.32103 10.079 12.4981 2.54E-02 0.243 5.87 79.06596 10.088 11.4992 2.32E-02 0.228 5.44 78.79666 10.069 10.4986 2.10E-02 0.213 5.00 78.52612 10.073 9.4983 1.89E-02 0.197 4.55 78.2525 10.077 8.4983 1.68E-02 0.180 4.09 77.97887 10.079 7.4983 1.47E-02 0.162 3.63 77.71018 10.082 6.4989 1.27E-02 0.144 3.18 77.43697 10.084 5.4988 1.06E-02 0.125 2.71 77.16437 10.084 4.4991 8.65E-03 0.106 2.25 76.89301 10.086 3.4987 6.68E-03 0.085 1.78 76.62103 10.086 2.499 4.74E-03 0.064 1.31 76.3476 10.069 1.4985 2.83E-03 0.041 0.84 76.07108 10.095 0.499 9.36E-04 0.018 0.35 75.92448 10.088 0.0946 1.77E-04 0.006 0.11 75.87086 13.571 0.0034 6.28E-06 0.002 0.03

161 TABLE D-3 CARBON DIOXIDE IN [bmim][BF4] (cont.)

10 oC 120 min JMC Q4 bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction (mg) (oC) (bar) (g / cm3) of Gas Wt % Gas 54.70261 22.456 0.000425 1.79E-06 4.67E-06 9.10E-05 54.70058 10.173 0.009905 1.85E-05 -1.42E-04 -2.77E-03 54.70623 10.019 0.047963 8.97E-05 0.001 0.01 54.71502 9.957 0.099211 1.86E-04 0.002 0.03 54.77259 10.019 0.498891 9.36E-04 0.009 0.18 54.86412 9.995 0.998869 1.88E-03 0.020 0.39 55.1382 10.024 2.500451 4.75E-03 0.051 1.03 55.45459 10.034 3.998324 7.66E-03 0.083 1.73 55.7845 10.019 5.49812 1.06E-02 0.115 2.46 56.10752 10.053 7.001625 1.37E-02 0.144 3.16 56.43209 9.952 8.499772 1.68E-02 0.171 3.86 56.74252 9.966 9.996684 1.99E-02 0.196 4.53 56.96606 9.909 10.99499 2.21E-02 0.213 5.00 57.17194 9.995 11.99522 2.43E-02 0.228 5.43 57.3765 10.043 13.00507 2.65E-02 0.243 5.87 57.3765 10.043 13.00507 2.65E-02 0.243 5.87 57.0918 10.053 10.99952 2.21E-02 0.220 5.20 56.70718 9.981 8.997277 1.78E-02 0.190 4.37 56.11668 10.053 6.002082 1.16E-02 0.140 3.08 55.85102 9.986 4.998692 9.64E-03 0.117 2.52

162 TABLE D-3 CARBON DIOXIDE IN [bmim][BF4] (cont.)

10 oC 90 min JMC Q1 bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction Wt % (mg) (oC) (bar) (g / cm3) of Gas Gas 66.94669 15.977 0.010043 1.84E-05 3.06E-05 5.95E-04 66.95139 16.088 0.048376 8.86E-05 5.08E-04 9.89E-03 66.95953 16.011 0.099074 1.82E-04 1.29E-03 0.03 67.01349 15.992 0.499853 9.18E-04 0.007 0.13 67.10433 16.059 0.999419 1.84E-03 0.015 0.29 67.38419 15.963 2.500451 4.64E-03 0.040 0.80 67.72782 15.79 3.997087 7.49E-03 0.068 1.39 68.08974 15.838 5.499219 1.04E-02 0.095 2.00 68.45602 15.823 6.992146 1.33E-02 0.121 2.62 68.81982 15.833 8.497438 1.64E-02 0.146 3.22 69.16536 16.035 9.993936 1.94E-02 0.168 3.79 69.41096 16.011 10.99595 2.15E-02 0.184 4.19 69.66375 15.9 12.00209 2.36E-02 0.199 4.60 69.89687 15.795 13.0015 2.58E-02 0.212 4.98 69.89687 15.795 13.0015 2.58E-02 0.212 4.98 69.68702 15.684 10.99829 2.15E-02 0.198 4.57 68.79775 15.727 6.00057 1.14E-02 0.139 3.04

163 TABLE D-3 CARBON DIOXIDE IN [bmim][BF4] (cont.)

25 oC 180 min Welton SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 75.90591 25.066 -0.001 3.21E-292 1.09E-291 2.12E-290 75.90448 25.077 0.0102 1.81E-05 -3.54E-05 -6.88E-04 75.91148 25.075 0.0473 8.40E-05 6.61E-04 1.29E-02 75.93808 25.07 0.1958 3.48E-04 0.003 0.07 76.00799 25.068 0.5945 1.06E-03 0.010 0.20 76.07912 25.077 0.9982 1.78E-03 0.017 0.34 76.25398 25.077 1.9965 3.58E-03 0.034 0.69 76.42905 25.075 2.9969 5.40E-03 0.051 1.03 76.60288 25.079 3.9991 7.25E-03 0.067 1.38 76.77341 25.077 4.9961 9.10E-03 0.082 1.71 76.94126 25.079 5.9967 1.10E-02 0.097 2.05 77.10869 25.081 6.9978 1.29E-02 0.111 2.38 77.27571 25.075 7.9977 1.48E-02 0.125 2.71 77.43944 25.081 8.9992 1.68E-02 0.138 3.03 77.60255 25.086 9.9992 1.87E-02 0.151 3.35 77.76338 25.075 10.997 2.07E-02 0.164 3.67 77.92298 25.077 11.9993 2.27E-02 0.176 3.99 78.08299 25.077 12.9993 2.48E-02 0.188 4.31 78.08299 25.095 12.9982 2.48E-02 0.188 4.31 78.0032 25.077 12.4989 2.37E-02 0.182 4.15 77.84504 25.075 11.4987 2.17E-02 0.170 3.83 77.68359 25.077 10.4986 1.97E-02 0.158 3.51 77.52336 25.075 9.4992 1.77E-02 0.145 3.20 77.36026 25.077 8.4995 1.58E-02 0.132 2.87 77.19716 25.075 7.4994 1.38E-02 0.118 2.55 77.03075 25.079 6.4973 1.19E-02 0.104 2.22 76.86455 25.073 5.4988 1.00E-02 0.090 1.89 76.69505 25.075 4.4985 8.17E-03 0.075 1.55 76.52452 25.073 3.499 6.32E-03 0.060 1.22 76.35234 25.077 2.4991 4.49E-03 0.043 0.88 76.17645 25.077 1.4976 2.68E-03 0.027 0.53 75.99871 25.073 0.4985 8.87E-04 0.009 0.18

164 TABLE D-3 CARBON DIOXIDE IN [bmim][BF4] (cont.)

25 oC 180 min JMC Q4 bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction Wt % (mg) (oC) (bar) (g / cm3) of Gas Gas 53.82434 31.042 0.000288 1.741E-06 4.55E-06 8.87E-05 53.82855 25.163 0.015264 2.71E-05 4.73E-04 9.20E-03 53.82585 25.009 0.049475 8.79E-05 3.74E-04 7.28E-03 53.83246 25.028 0.099486 1.77E-04 1.24E-03 2.41E-02 53.88169 25.004 0.499441 8.89E-04 0.008 0.15 53.94711 25.014 0.998869 1.78E-03 0.016 0.32 54.14374 24.995 2.497704 4.49E-03 0.041 0.82 54.35253 25.028 4.001209 7.25E-03 0.065 1.33 54.55667 25.028 5.499082 1.00E-02 0.088 1.84 54.76052 25.028 6.997503 1.29E-02 0.110 2.34 54.95833 25.019 8.49785 1.58E-02 0.130 2.83 55.15114 25.014 9.999706 1.87E-02 0.149 3.31 55.27419 25.043 10.99636 2.07E-02 0.161 3.61 55.39894 24.999 12.00388 2.27E-02 0.173 3.92 55.51863 24.999 12.99765 2.48E-02 0.185 4.22 55.51863 24.999 12.99765 2.48E-02 0.185 4.22 55.30754 25.014 10.99746 2.07E-02 0.164 3.67 55.0512 24.999 8.998651 1.68E-02 0.139 3.04

165 TABLE D-3 CARBON DIOXIDE IN [bmim][BF4] (cont.)

25 oC 120 min JMC Q4 bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction Wt % (mg) (oC) (bar) (g / cm3) of Gas Gas 53.96712 25.433 0.000425 1.77E-06 4.65E-06 9.05E-05 53.96664 21.344 0.015538 2.79E-05 2.75E-05 5.36E-04 53.97173 21.359 0.048376 8.70E-05 6.66E-04 1.30E-02 53.97944 21.32 0.100173 1.80E-04 1.64E-03 0.03 54.02997 21.224 0.498617 8.99E-04 0.008 0.16 54.10339 21.171 0.998594 1.81E-03 0.017 0.34 54.31937 21.06 2.499627 4.56E-03 0.044 0.88 54.55033 21.003 4.002446 7.36E-03 0.070 1.44 54.77959 20.983 5.498944 1.02E-02 0.094 1.99 55.00725 21.012 6.999839 1.31E-02 0.118 2.53 55.23246 20.964 8.500048 1.60E-02 0.140 3.07 55.44972 20.926 9.998332 1.90E-02 0.160 3.58 55.60352 20.863 10.99719 2.11E-02 0.174 3.94 55.74737 20.834 12.0014 2.31E-02 0.187 4.29 55.89041 20.82 12.99765 2.52E-02 0.199 4.63 55.89041 20.82 12.99765 2.52E-02 0.199 4.63 55.65372 20.829 10.99856 2.11E-02 0.177 4.03 55.09212 20.887 6.997366 1.31E-02 0.124 2.68

166 TABLE D-3 CARBON DIOXIDE IN [bmim][BF4] (cont.)

25 oC 90 min JMC Q1 bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction (mg) (oC) (bar) (g / cm3) of Gas Wt % Gas 66.96526 33.5 0.000562 1.73E-06 2.93E-06 5.71E-05 66.96066 24.71 0.011416 2.03E-05 -3.19E-04 -6.20E-03 66.96571 24.999 0.048238 8.57E-05 1.80E-04 3.50E-03 66.97429 24.441 0.100448 1.79E-04 9.95E-04 1.94E-02 67.01988 25.086 0.501639 8.93E-04 0.006 0.11 67.10281 25.014 0.998869 1.78E-03 0.013 0.26 67.33811 24.99 2.497429 4.49E-03 0.035 0.70 67.61900 25.004 3.997774 7.25E-03 0.059 1.20 67.90485 24.995 5.498669 1.00E-02 0.082 1.71 68.19481 25.004 6.998466 1.29E-02 0.104 2.21 68.47971 25.019 8.496612 1.58E-02 0.125 2.71 68.76072 25.009 9.998194 1.87E-02 0.145 3.19 68.95742 25.004 10.99939 2.07E-02 0.158 3.53 69.13815 25.014 11.99934 2.27E-02 0.170 3.84 69.32124 24.999 12.99944 2.48E-02 0.182 4.16 69.32124 24.999 12.99944 2.48E-02 0.182 4.16 69.12540 25.125 10.9987 2.07E-02 0.167 3.76 68.30669 25.009 5.997686 1.10E-02 0.108 2.31 66.95254 25.578 0.000562 1.77E-06 -0.001 -0.02

167 TABLE D-3 CARBON DIOXIDE IN [bmim][BF4] (cont.)

50 oC 180 min Welton SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density (g Fraction of (mg) (oC) (bar) / cm3) Gas Wt % Gas 75.83025 50.087 -0.001 3.21E-292 1.11E-291 2.15E-290 75.83065 50.019 0.0098 1.61E-05 8.25E-05 1.61E-03 75.83086 50.019 0.0477 7.82E-05 3.11E-04 6.05E-03 75.83828 50.022 0.1953 3.20E-04 1.65E-03 3.21E-02 75.86983 50.022 0.5971 9.81E-04 0.006 0.12 75.90715 50.019 0.9978 1.64E-03 0.011 0.21 75.97375 50.019 1.9974 3.30E-03 0.021 0.41 76.07789 50.033 2.9985 4.97E-03 0.033 0.66 76.15068 50.035 3.9992 6.66E-03 0.043 0.86 76.21687 50.017 4.9988 8.35E-03 0.052 1.06 76.28925 50.004 5.9987 1.01E-02 0.062 1.26 76.37317 50.01 6.9966 1.18E-02 0.072 1.48 76.42452 50.031 7.9992 1.35E-02 0.080 1.66 76.50266 49.984 8.9973 1.53E-02 0.089 1.88 76.56679 50.035 9.9973 1.70E-02 0.098 2.07 76.63918 50.006 10.9983 1.88E-02 0.107 2.28 76.70227 50.008 11.9985 2.06E-02 0.115 2.47 76.74825 50.013 12.9988 2.24E-02 0.122 2.64 76.74867 50.052 12.9981 2.24E-02 0.122 2.65 76.71423 50.013 12.4979 2.15E-02 0.118 2.54 76.65402 50.002 11.4981 1.97E-02 0.110 2.35 76.59545 50.002 10.4969 1.79E-02 0.102 2.16 76.54329 49.995 9.4981 1.62E-02 0.094 1.98 76.47916 50.019 8.4977 1.44E-02 0.086 1.79 76.40307 50.006 7.4978 1.27E-02 0.076 1.58 76.34059 50.024 6.4984 1.09E-02 0.067 1.39 76.2711 50.013 5.4978 9.20E-03 0.058 1.18 76.1946 50.017 4.4985 7.50E-03 0.048 0.97 76.12016 50.015 3.4987 5.81E-03 0.038 0.77 76.0482 50.006 2.4982 4.13E-03 0.028 0.56 75.96736 50.019 1.4983 2.47E-03 0.017 0.35 75.88158 50.019 0.499 8.19E-04 0.006 0.12 75.8556 50.013 0.095 1.56E-04 0.002 0.04 75.85086 50.026 0.0293 4.80E-05 0.002 0.03

168 TABLE D-3 CARBON DIOXIDE IN [bmim][BF4] (cont.)

50 oC 120 min JMC Q4 bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction Wt % (mg) (oC) (bar) (g / cm3) of Gas Gas 53.92284 50.8 0.000288 1.63E-06 4.38E-06 8.52E-05 53.92445 50.003 0.010043 1.65E-05 1.97E-04 3.84E-03 53.9278 49.999 0.048101 7.88E-05 6.83E-04 1.33E-02 53.93228 50.013 0.099349 1.63E-04 1.33E-03 2.60E-02 53.96182 50.008 0.498891 8.19E-04 0.006 0.11 54.0007 50.013 0.998869 1.64E-03 0.012 0.23 54.08841 50.037 2.498116 4.13E-03 0.026 0.52 54.22266 50.023 3.997637 6.65E-03 0.044 0.89 54.30724 49.95 5.498669 9.21E-03 0.058 1.18 54.42856 49.95 6.998053 1.18E-02 0.074 1.53 54.49009 50.023 8.496888 1.44E-02 0.085 1.77 54.61763 50.018 10.00561 1.71E-02 0.101 2.13 54.65562 50.003 10.99898 1.88E-02 0.107 2.29 54.71508 49.974 11.99879 2.06E-02 0.116 2.48 54.78723 50.042 12.99944 2.24E-02 0.125 2.70 54.78723 50.042 12.99944 2.24E-02 0.125 2.70 54.63004 50.042 10.99774 1.88E-02 0.105 2.24 54.53248 50.042 9.001262 1.53E-02 0.090 1.89 54.34235 50.028 5.99906 1.01E-02 0.063 1.29

169 TABLE D-3 CARBON DIOXIDE IN [bmim][BF4] (cont.)

50 oC 180 min JMC Q1 bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction (mg) (oC) (bar) (g / cm3) of Gas Wt % Gas 67.06097 48.023 0.000425 1.65E-06 2.90E-06 5.64E-05 67.0596 50.052 0.011142 1.83E-05 -7.29E-05 -1.42E-03 67.06271 49.94 0.049337 8.09E-05 2.75E-04 5.36E-03 67.06738 49.936 0.099074 1.62E-04 7.76E-04 1.51E-02 67.10722 50.008 0.499578 8.20E-04 0.005 0.10 67.16016 49.965 0.999007 1.64E-03 0.010 0.20 67.30943 49.669 2.497704 4.14E-03 0.026 0.51 67.46609 49.474 3.999011 6.67E-03 0.041 0.83 67.64283 49.382 5.501142 9.23E-03 0.057 1.17 67.80647 49.581 6.999702 1.18E-02 0.072 1.49 67.96945 49.528 8.491941 1.44E-02 0.087 1.81 68.10647 49.314 9.989951 1.71E-02 0.099 2.10 68.20345 49.295 10.99636 1.89E-02 0.108 2.30 68.31441 49.241 12.00017 2.07E-02 0.117 2.51 68.37747 49.13 12.99765 2.25E-02 0.123 2.66 68.37747 49.13 12.99765 2.25E-02 0.123 2.66 68.24625 49.411 11.00021 1.89E-02 0.110 2.36 67.75753 49.683 6.000434 1.01E-02 0.066 1.36

170 TABLE D-4 CARBON DIOXIDE IN [bmim][PF6]

10 oC 90 min Sachem SS bucket

Mass Sample Sample Mole Reading Temperature Pressure Gas Density Fraction Wt % (mg) (oC) (bar) (g / cm3) of Gas Gas 76.71907 16.688 0.0001 1.83E-06 6.59E-06 1.02E-04 76.8186 10.079 0.499 9.36E-04 0.012 0.18 76.93568 10.084 1.0007 1.88E-03 0.024 0.39 77.05647 10.079 1.4988 2.83E-03 0.037 0.59 77.1783 10.079 1.9995 3.78E-03 0.050 0.80 77.2991 10.079 2.4987 4.74E-03 0.062 1.01 77.42051 10.079 3.0018 5.72E-03 0.074 1.22 77.53944 10.082 3.502 6.69E-03 0.085 1.42 77.65714 10.084 3.996 7.66E-03 0.096 1.62 77.77628 10.079 4.4959 8.64E-03 0.107 1.83 77.89729 10.079 4.9948 9.63E-03 0.118 2.03 78.01333 10.082 5.4959 1.06E-02 0.128 2.23 78.13331 10.086 5.9954 1.16E-02 0.139 2.43 78.25079 10.079 6.4955 1.26E-02 0.149 2.63 78.36974 10.088 6.9967 1.37E-02 0.158 2.83 78.48785 10.079 7.4961 1.47E-02 0.168 3.03 78.60761 10.084 7.9945 1.57E-02 0.177 3.23 78.72509 10.086 8.4943 1.68E-02 0.187 3.43 78.85043 10.082 8.9955 1.78E-02 0.196 3.63 78.97371 10.082 9.4945 1.89E-02 0.205 3.84 79.08438 10.088 9.9958 1.99E-02 0.213 4.03 79.20229 10.079 10.4958 2.10E-02 0.222 4.22 79.3237 10.082 10.9896 2.21E-02 0.230 4.42 79.44429 10.082 11.4896 2.31E-02 0.238 4.62 79.55848 10.088 11.9901 2.42E-02 0.246 4.81 79.6832 10.079 12.4894 2.53E-02 0.254 5.01 79.80254 10.082 12.9898 2.64E-02 0.262 5.21 79.80254 10.05 12.9902 2.64E-02 0.262 5.21 79.69001 10.077 12.5002 2.54E-02 0.255 5.02 79.56715 10.079 12.0014 2.43E-02 0.247 4.82 79.45235 10.082 11.5009 2.32E-02 0.239 4.63 79.33341 10.084 11.0013 2.21E-02 0.231 4.43 79.21468 10.079 10.5018 2.10E-02 0.222 4.24 79.09492 10.082 10.0012 1.99E-02 0.214 4.04 78.97453 10.084 9.5016 1.89E-02 0.205 3.84 78.85518 10.084 9.0009 1.78E-02 0.196 3.64 78.73707 10.079 8.5009 1.68E-02 0.187 3.44 78.6169 10.079 8.0004 1.57E-02 0.178 3.24 78.49796 10.079 7.501 1.47E-02 0.169 3.04 78.38088 10.082 7.0003 1.37E-02 0.159 2.85 78.26112 10.084 6.5018 1.27E-02 0.149 2.64

171 TABLE D-4 CARBON DIOXIDE IN [bmim][PF6] (cont.)

78.14321 10.079 6.0015 1.16E-02 0.139 2.45 78.02345 10.086 5.5004 1.06E-02 0.129 2.24 77.90534 10.082 5.0002 9.64E-03 0.119 2.04 77.78785 10.079 4.502 8.65E-03 0.108 1.84 77.66995 10.082 4.0014 7.67E-03 0.097 1.64 77.55142 10.082 3.4998 6.68E-03 0.086 1.44 77.43476 10.086 3.0001 5.71E-03 0.075 1.24 77.31727 10.079 2.501 4.75E-03 0.063 1.03 77.19936 10.091 1.9996 3.78E-03 0.051 0.83 77.08456 10.082 1.5046 2.84E-03 0.039 0.63 76.96479 10.079 0.9989 1.88E-03 0.027 0.42 76.84709 10.084 0.4989 9.36E-04 0.014 0.22 76.73787 10.084 0.0317 5.93E-05 1.79E-03 2.78E-02

TABLE D-4 CARBON DIOXIDE IN [bmim][PF6] (cont.)

25 oC 90 min Sachem SS bucket

Mass Sample Sample Mole Reading Temperature Pressure Gas Density Fraction Wt % (mg) (oC) (bar) (g / cm3) of Gas Gas 76.73683 26.5 0.0003 1.77E-06 6.45E-06 9.98E-05 76.78867 25.066 0.5026 8.95E-04 0.008 0.12 76.86217 25.07 1.0019 1.79E-03 0.017 0.26 76.94394 25.073 1.4989 2.68E-03 0.026 0.42 77.01889 25.079 2.0022 3.59E-03 0.036 0.57 77.09674 25.07 2.5002 4.50E-03 0.045 0.72 77.17252 25.079 3.0013 5.41E-03 0.053 0.87 77.24748 25.07 3.5005 6.33E-03 0.062 1.01 77.32222 25.079 3.9972 7.24E-03 0.070 1.16 77.40813 25.073 4.4965 8.17E-03 0.079 1.32 77.48741 25.075 4.9968 9.10E-03 0.088 1.47 77.56175 25.068 5.4967 1.00E-02 0.096 1.62 77.6334 25.07 5.9969 1.10E-02 0.104 1.76 77.69163 25.07 6.4972 1.19E-02 0.110 1.88 77.78475 25.059 6.997 1.29E-02 0.119 2.05 77.85372 25.073 7.4964 1.38E-02 0.126 2.19 77.92847 25.07 7.9947 1.48E-02 0.134 2.33 77.99889 25.075 8.4957 1.58E-02 0.141 2.47 78.06764 25.073 8.9964 1.67E-02 0.148 2.61 78.13867 25.075 9.4967 1.77E-02 0.154 2.75 78.20889 25.079 9.9975 1.87E-02 0.161 2.89 78.27929 25.079 10.4973 1.97E-02 0.168 3.03 78.35548 25.075 10.9906 2.07E-02 0.175 3.17 78.42073 25.075 11.4911 2.17E-02 0.181 3.31

172 TABLE D-4 CARBON DIOXIDE IN [bmim][PF6] (cont.)

78.49011 25.079 11.9903 2.27E-02 0.187 3.44 78.54916 25.077 12.4912 2.37E-02 0.193 3.57 78.62888 25.077 12.9907 2.47E-02 0.200 3.72 78.62888 25.086 12.988 2.47E-02 0.200 3.72 78.57127 25.075 12.5011 2.37E-02 0.194 3.60 78.47463 25.031 12.0025 2.27E-02 0.186 3.43 78.41743 25.064 11.5007 2.17E-02 0.181 3.30 78.35073 25.075 11.0022 2.07E-02 0.175 3.17 78.2702 25.084 10.5014 1.97E-02 0.167 3.02 78.19772 25.068 10.0019 1.87E-02 0.161 2.88 78.13186 25.079 9.5022 1.77E-02 0.154 2.74 78.05649 25.073 9.0023 1.68E-02 0.147 2.60 77.9869 25.077 8.5023 1.58E-02 0.140 2.46 77.91608 25.075 8.0023 1.48E-02 0.133 2.32 77.83968 25.075 7.5068 1.39E-02 0.125 2.17 77.77051 25.075 7.0073 1.29E-02 0.118 2.03 77.69493 25.075 6.5072 1.20E-02 0.111 1.89 77.62348 25.077 6.0076 1.10E-02 0.103 1.75 77.5508 25.073 5.5075 1.01E-02 0.095 1.60 77.48039 25.077 5.007 9.12E-03 0.087 1.46 77.40709 25.081 4.5066 8.19E-03 0.079 1.32 77.33234 25.07 4.008 7.26E-03 0.071 1.17 77.25924 25.077 3.5069 6.34E-03 0.063 1.03 77.18697 25.073 3.0073 5.42E-03 0.055 0.88 77.11223 25.073 2.5076 4.51E-03 0.046 0.74 77.03686 25.081 2.0062 3.60E-03 0.037 0.59 76.96293 25.093 1.5053 2.69E-03 0.028 0.44 76.88798 25.075 1.0051 1.79E-03 0.019 0.30 76.81571 25.079 0.5054 9.00E-04 0.010 0.15 76.74261 25.523 0.0333 5.91E-05 7.01E-04 1.09E-02

TABLE D-4 CARBON DIOXIDE IN [bmim][PF6] (cont.)

50 oC 90 min Sachem SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 76.72588 50.035 0 3.21E-292 1.2E-291 1.8E-290 76.73849 49.998 0.4991 8.19E-04 0.004 0.06 76.774 50.015 1.0008 1.65E-03 0.010 0.16 76.82604 50.019 1.5021 2.48E-03 0.017 0.27 76.84998 50.033 2.0012 3.30E-03 0.022 0.35 76.90925 50.002 2.4993 4.14E-03 0.030 0.47 76.93939 50.019 3.0018 4.98E-03 0.035 0.56

173 TABLE D-4 CARBON DIOXIDE IN [bmim][PF6] (cont.) 76.98007 50.013 3.4992 5.81E-03 0.041 0.66 77.01518 50.024 3.9967 6.65E-03 0.047 0.75 77.05709 50.01 4.4953 7.50E-03 0.053 0.86 77.09303 50.017 4.9967 8.35E-03 0.058 0.95 77.13577 50.008 5.4961 9.20E-03 0.064 1.05 77.16137 50.026 5.9953 1.01E-02 0.069 1.13 77.20287 50.015 6.4954 1.09E-02 0.075 1.23 77.23591 50.002 6.9945 1.18E-02 0.080 1.33 77.26461 50.037 7.4966 1.27E-02 0.085 1.41 77.29683 50.024 7.997 1.35E-02 0.090 1.50 77.32615 50.019 8.4961 1.44E-02 0.094 1.59 77.35464 50.002 8.996 1.53E-02 0.099 1.67 77.3852 50.031 9.4955 1.62E-02 0.104 1.76 77.41473 50.004 9.9949 1.70E-02 0.108 1.84 77.44115 50.019 10.4955 1.79E-02 0.113 1.93 77.46367 50.026 10.9899 1.88E-02 0.117 2.00 77.49526 50.026 11.4899 1.97E-02 0.121 2.09 77.52974 50.013 11.9903 2.06E-02 0.126 2.19 77.55721 50.019 12.49 2.15E-02 0.130 2.27 77.57269 50.019 12.9904 2.24E-02 0.134 2.34 77.57207 49.993 12.9908 2.24E-02 0.134 2.34 77.53862 50.022 12.5016 2.15E-02 0.129 2.25 77.5157 50.026 12.0016 2.06E-02 0.125 2.17 77.48493 50.028 11.5013 1.97E-02 0.121 2.08 77.46119 50.019 11.0015 1.88E-02 0.117 2.00 77.43352 50.033 10.5017 1.79E-02 0.112 1.92 77.4139 50.015 10.0016 1.71E-02 0.108 1.84 77.3821 50.013 9.5015 1.62E-02 0.103 1.75 77.34597 50 9.0017 1.53E-02 0.098 1.66 77.31458 50.006 8.5012 1.44E-02 0.093 1.57 77.28381 50.01 8.0016 1.35E-02 0.089 1.48 77.24665 50.015 7.5066 1.27E-02 0.083 1.39 77.22022 50.01 7.0053 1.18E-02 0.079 1.31 77.18883 50.019 6.5068 1.09E-02 0.074 1.22 77.15435 50.013 6.0069 1.01E-02 0.068 1.13 77.11264 50.015 5.5073 9.22E-03 0.063 1.02 77.08393 49.995 5.0062 8.37E-03 0.058 0.94 77.04842 50.028 4.5072 7.52E-03 0.052 0.85 76.99948 50.024 4.0078 6.67E-03 0.046 0.74 76.96521 50.017 3.5079 5.83E-03 0.040 0.64 76.92371 50.019 3.0072 4.99E-03 0.034 0.54 76.90099 50.022 2.507 4.15E-03 0.029 0.46 76.87311 49.995 2.0061 3.31E-03 0.024 0.38 76.82789 50.013 1.505 2.48E-03 0.017 0.27 76.78783 50.013 1.0047 1.65E-03 0.011 0.18 76.75438 50.013 0.5048 8.29E-04 0.005 0.08 76.71886 49.813 0.0378 6.20E-05 -3.61E-04 -5.58E-03

174 TABLE D-5 CARBON DIOXIDE IN [bmim][Tf2N]

10 oC 90 min Covalent Q1 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of Wt % (mg) (oC) (bar) (g / cm3) Gas Gas 79.29511 11.838 0.022545 4.19E-05 1.06E-04 1.12E-03 79.29761 10.158 0.05181 9.69E-05 5.46E-04 5.74E-03 79.30821 10.149 0.098937 1.85E-04 0.002 0.02 79.38007 10.014 0.499029 9.36E-04 0.012 0.13 79.49729 9.875 0.999968 1.88E-03 0.028 0.30 79.83124 10.163 2.498665 4.74E-03 0.071 0.80 80.26686 10.053 3.998049 7.66E-03 0.120 1.41 80.73273 10.014 5.502242 1.06E-02 0.167 2.05 81.21191 10.067 6.99819 1.37E-02 0.210 2.71 81.7007 9.995 8.498812 1.68E-02 0.249 3.36 82.18835 9.966 9.998058 1.99E-02 0.285 4.01 82.54935 10.019 10.99898 2.21E-02 0.309 4.48 83.02369 9.952 12.00017 2.43E-02 0.338 5.08 83.22673 10.408 12.99724 2.64E-02 0.351 5.36 83.22673 10.408 12.99724 2.64E-02 0.351 5.36 82.74361 10.187 10.99856 2.21E-02 0.320 4.70 81.23637 9.928 5.998785 1.16E-02 0.208 2.68 80.0636 9.933 1.999237 3.79E-03 0.093 1.06 79.52804 9.981 0.198273 3.71E-04 0.028 0.30 79.40803 10.01 0.073107 1.37E-04 0.014 0.15 79.35766 10.038 0.023507 4.40E-05 0.008 0.08

175 TABLE D-5 CARBON DIOXIDE IN [bmim][Tf2N] (cont.)

25 oC 90 min Covalent Q1 Bucket

Mass Sample Sample Gas Mole Wt % Gas Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas 64.02643 29.334 0.000425 1.75E-06 2.88E-06 3.02E-05 64.02689 24.946 0.012653 2.25E-05 1.05E-04 1.11E-03 64.03357 25.019 0.047826 8.50E-05 0.001 0.01 64.04387 24.98 0.099074 1.76E-04 0.003 0.03 64.1179 24.999 0.499578 8.90E-04 0.015 0.16 64.21387 24.98 0.999007 1.78E-03 0.030 0.32 64.49826 25.004 2.498528 4.49E-03 0.072 0.81 64.78852 25.004 3.997774 7.25E-03 0.111 1.30 65.08781 25.014 5.498807 1.00E-02 0.149 1.80 65.382 25.067 6.996405 1.29E-02 0.182 2.29 65.67616 25.033 8.499086 1.58E-02 0.214 2.77 65.96083 24.927 10.00479 1.87E-02 0.242 3.24 66.15311 24.922 10.99746 2.07E-02 0.260 3.55 66.33513 24.995 11.9955 2.27E-02 0.276 3.84 66.52163 25.019 12.99985 2.48E-02 0.292 4.14 66.52163 25.019 12.99985 2.48E-02 0.292 4.14 66.14674 25.014 10.99856 2.07E-02 0.259 3.54 65.17657 25.009 5.998098 1.10E-02 0.159 1.95 64.41748 25.004 1.9991 3.59E-03 0.060 0.67 64.07732 25.028 0.198685 3.53E-04 0.008 0.09 64.04392 24.995 0.072969 1.30E-04 0.003 0.03 64.03729 25.028 0.023507 4.18E-05 1.68E-03 1.77E-02

176 TABLE D-5 CARBON DIOXIDE IN [bmim][Tf2N] (cont.)

50 oC 90 min Covalent Q1 Bucket

Mass Sample Sample Gas Mole Wt % Gas Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas 64.03474 48.63 0.024057 3.96E-05 6.93E-05 7.27E-04 64.03756 49.984 0.048238 7.91E-05 5.58E-04 5.86E-03 64.04441 50.008 0.098662 1.62E-04 1.72E-03 1.81E-02 64.09399 50.013 0.498617 8.19E-04 0.010 0.11 64.15556 50.013 0.999144 1.64E-03 0.020 0.22 64.32733 49.96 2.49839 4.13E-03 0.048 0.53 64.52599 49.989 3.999698 6.66E-03 0.078 0.88 64.70661 50.013 5.499356 9.21E-03 0.104 1.20 64.8787 49.989 7.000801 1.18E-02 0.128 1.51 65.04067 50.033 8.49675 1.44E-02 0.149 1.80 65.20152 50.033 9.99792 1.70E-02 0.169 2.09 65.32343 50.052 10.99815 1.88E-02 0.184 2.30 65.43156 50.013 11.99934 2.06E-02 0.196 2.50 65.53699 49.926 12.9938 2.24E-02 0.208 2.68 65.53699 49.926 12.9938 2.24E-02 0.208 2.68 65.3199 49.965 10.99774 1.88E-02 0.183 2.30 64.74528 50.018 5.999609 1.01E-02 0.110 1.28 64.25959 50.028 1.999649 3.30E-03 0.038 0.41 64.04314 49.999 0.19841 3.25E-04 1.82E-03 1.91E-02 64.02586 50.023 0.073107 1.20E-04 -1.11E-03 -1.17E-02 64.02161 50.013 0.021309 3.49E-05 -1.90E-03 -1.99E-02

177 TABLE D-6 CARBON DIOXIDE IN [bmmim][BF4]

10 oC 180 min Welton SS Bucket

Mass Sample Sample Mole Reading Temperature Pressure Gas Density Fraction of Wt % (mg) (oC) (bar) (g / cm3) Gas Gas 76.20087 11.733 0.00E+00 3.21E-292 1.27E-291 0.00 76.2147 10.075 7.20E-03 1.35E-05 1.04E-03 0.02 76.21716 10.082 4.86E-02 9.09E-05 1.52E-03 0.03 76.24088 10.095 1.97E-01 3.69E-04 4.31E-03 0.08 76.30624 10.082 5.97E-01 1.12E-03 1.18E-02 0.22 76.38295 10.079 9.99E-01 1.88E-03 2.01E-02 0.37 76.55719 10.075 2.00E+00 3.78E-03 3.89E-02 0.74 76.75226 10.082 3.00E+00 0.0057 5.84E-02 1.12 76.95888 10.077 4.00E+00 0.0076 7.80E-02 1.53 77.16611 10.082 5.00E+00 0.0096 9.68E-02 1.93 77.37025 10.091 6.00E+00 0.0116 1.15E-01 2.32 77.57273 10.088 7.00E+00 0.0137 1.32E-01 2.71 77.76822 10.082 8.00E+00 0.0157 1.48E-01 3.10 77.96535 10.077 9.00E+00 0.0178 1.64E-01 3.48 78.15382 10.086 1.00E+01 0.0199 1.79E-01 3.85 78.33507 10.079 1.10E+01 0.0221 1.94E-01 4.21 78.51385 10.079 1.20E+01 0.0242 2.07E-01 4.57 78.69366 10.079 1.30E+01 0.0265 2.21E-01 4.93 78.69386 10.079 1.30E+01 0.0265 2.21E-01 4.93 78.64293 10.086 1.25E+01 0.0254 2.16E-01 4.80 78.48292 10.082 1.15E+01 0.0231 2.03E-01 4.46 78.30888 10.086 1.05E+01 0.0210 1.90E-01 4.11 78.13238 10.079 9.50E+00 0.0189 1.76E-01 3.75 77.94556 10.086 8.50E+00 0.0168 1.61E-01 3.39 77.76244 10.079 7.50E+00 0.0147 1.45E-01 3.02 77.57378 10.082 6.50E+00 0.0126 1.29E-01 2.65 77.38633 10.082 5.50E+00 0.0106 1.13E-01 2.27 77.19168 10.079 4.50E+00 0.0086 9.51E-02 1.89 76.99435 10.079 3.50E+00 0.0067 7.68E-02 1.50 76.78959 10.082 2.50E+00 0.0047 5.74E-02 1.10 76.57349 10.084 1.50E+00 0.0028 3.65E-02 0.69 76.33099 10.084 4.99E-01 0.0009 1.29E-02 0.24 76.2615 10.079 9.55E-02 1.79E-04 5.02E-03 0.09 76.22995 12.999 3.70E-03 6.85E-06 2.11E-03 0.04

178 TABLE D-6 CARBON DIOXIDE IN [bmmim][BF4] (cont.)

25 oC 180 min Welton SS Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density (g / Fraction of (mg) (oC) (bar) cm3) Gas Wt % Gas 76.19221 24.993 0 3.21E-292 1.30E-291 2.37E-290 76.2083 25.075 0.0105 1.86E-05 1.23E-03 2.25E-02 76.2147 25.073 0.0481 8.54E-05 1.95E-03 3.58E-02 76.23119 25.075 0.1972 3.51E-04 0.004 0.08 76.27943 25.07 0.5981 1.07E-03 0.010 0.19 76.32975 25.075 0.9993 1.78E-03 0.017 0.31 76.44894 25.07 1.9979 0.004 0.032 0.60 76.57307 25.068 2.9978 0.005 0.047 0.89 76.69493 25.077 3.9962 0.007 0.061 1.18 76.81619 25.068 4.9982 0.009 0.075 1.47 76.93144 25.079 5.9973 0.011 0.089 1.75 77.0463 25.081 6.9974 0.013 0.102 2.03 77.15807 25.073 7.9968 0.015 0.114 2.31 77.26612 25.077 8.9979 0.017 0.126 2.58 77.37437 25.07 9.9982 0.019 0.138 2.85 77.47912 25.093 10.9994 0.021 0.150 3.12 77.56676 25.079 12 0.023 0.160 3.37 77.66284 25.079 12.9995 0.025 0.170 3.63 77.66284 25.077 12.9998 0.025 0.170 3.63 77.62222 25.07 12.4986 0.024 0.165 3.51 77.52551 25.075 11.4984 0.022 0.155 3.25 77.42386 25.075 10.4978 0.020 0.144 2.98 77.32076 25.075 9.4985 0.018 0.132 2.72 77.21436 25.075 8.5 0.016 0.120 2.45 77.10775 25.084 7.4998 0.014 0.108 2.18 76.99744 25.081 6.4996 0.012 0.096 1.90 76.88464 25.079 5.4979 0.010 0.083 1.63 76.76979 25.073 4.4984 0.008 0.069 1.34 76.65081 25.079 3.498 0.006 0.055 1.06 76.52895 25.075 2.499 0.004 0.041 0.77 76.40687 25.075 1.4986 0.003 0.026 0.48 76.2683 25.077 0.4994 8.89E-04 0.009 0.17 76.21635 25.079 0.0965 1.71E-04 0.002 0.04 76.20108 25.029 0.0035 6.22E-06 6.60E-04 1.21E-02

179 TABLE D-6 CARBON DIOXIDE IN [bmmim][BF4] (cont.)

50 oC 180 min Welton SS Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 76.20397 50.035 0.0003 1.64E-06 6.86E-06 1.26E-04 76.20087 50.019 0.0077 1.26E-05 -1.69E-04 -3.10E-03 76.20232 50.031 0.0486 7.96E-05 2.15E-04 3.95E-03 76.21181 50.017 0.197 3.23E-04 0.002 0.04 76.23263 50.015 0.5976 9.81E-04 0.006 0.11 76.25593 50.019 0.9987 1.64E-03 0.010 0.19 76.31841 50.019 1.9991 0.003 0.022 0.40 76.36584 50.024 2.9995 0.005 0.031 0.59 76.41863 50.026 3.9976 0.007 0.041 0.79 76.46317 50.015 4.9985 0.008 0.051 0.97 76.50481 50.019 5.9994 0.010 0.060 1.15 76.54833 50.024 6.9969 0.012 0.069 1.34 76.58606 50.019 7.9967 0.014 0.077 1.52 76.62359 50.013 8.9972 0.015 0.086 1.69 76.64792 50.002 9.997 0.017 0.094 1.86 76.70628 50.015 10.999 0.019 0.103 2.06 76.70236 50.006 11.9992 0.021 0.109 2.19 76.71845 50.033 12.9972 0.022 0.116 2.34 76.71288 50.033 12.9965 0.022 0.115 2.33 76.71536 50.074 12.4989 0.022 0.112 2.27 76.6609 49.989 11.4987 0.020 0.103 2.07 76.65844 50.017 10.4995 0.018 0.097 1.93 76.6405 50.013 9.4982 0.016 0.090 1.78 76.59596 50.013 8.4985 0.014 0.081 1.59 76.56276 50.035 7.4993 0.013 0.073 1.42 76.51719 50.015 6.4994 0.011 0.064 1.23 76.47451 50.006 5.4994 0.009 0.055 1.05 76.42873 50.013 4.4979 0.008 0.045 0.86 76.38667 50.01 3.4978 0.006 0.036 0.68 76.34934 50.019 2.4991 0.004 0.027 0.51 76.26521 50.017 1.499 0.002 0.015 0.27 76.22026 50.019 0.4993 8.20E-04 0.005 0.08 76.19593 50.022 0.0957 1.57E-04 8.10E-05 1.48E-03 76.18602 50.201 0.0038 6.22E-06 -1.26E-03 -2.31E-02

180 TABLE D-7 CARBON DIOXIDE IN [bmmim][PF6]

10 oC 180 min Welton SS Bucket

Mass Sample Sample Gas Reading Temperature Pressure Density (g Wt % (mg) (oC) (bar) / cm3) Mole Fraction of Gas Gas 77.73312 14.607 3.00E-04 1.84E-06 7.85E-06 0.00 77.71951 10.073 8.50E-03 1.59E-05 -1.12E-03 -0.02 77.72096 10.093 4.96E-02 9.28E-05 -6.65E-04 -0.01 77.73704 10.064 1.98E-01 3.70E-04 1.92E-03 0.03 77.77849 10.075 5.98E-01 1.12E-03 8.67E-03 0.13 77.83231 10.082 1.00E+00 1.88E-03 1.64E-02 0.25 77.94943 10.073 2.00E+00 3.79E-03 3.38E-02 0.51 78.09603 10.088 3.00E+00 5.71E-03 5.30E-02 0.82 78.25626 10.066 4.00E+00 7.66E-03 7.26E-02 1.14 78.42328 10.093 5.00E+00 9.64E-03 9.20E-02 1.47 78.5938 10.079 6.00E+00 1.16E-02 1.11E-01 1.81 78.76537 10.077 7.00E+00 1.37E-02 1.29E-01 2.14 78.93568 10.059 8.00E+00 1.57E-02 1.47E-01 2.47 79.10683 10.055 9.00E+00 1.78E-02 1.64E-01 2.81 79.27077 10.102 1.00E+01 1.99E-02 1.80E-01 3.13 79.43718 10.12 1.10E+01 2.21E-02 1.95E-01 3.46 79.60852 10.095 1.20E+01 2.43E-02 2.11E-01 3.79 79.77143 10.069 1.30E+01 2.65E-02 2.25E-01 4.11 79.77143 10.066 1.30E+01 2.65E-02 2.25E-01 4.11 79.73947 10.053 1.25E+01 2.54E-02 2.21E-01 4.01 79.61018 10.086 1.15E+01 2.32E-02 2.08E-01 3.73 79.45841 10.022 1.05E+01 2.10E-02 1.94E-01 3.42 79.30273 10.062 9.50E+00 1.89E-02 1.79E-01 3.11 79.15179 10.037 8.50E+00 1.68E-02 1.63E-01 2.80 78.99941 10.088 7.50E+00 1.47E-02 1.48E-01 2.49 78.84702 10.093 6.50E+00 1.27E-02 1.31E-01 2.18 78.6967 10.075 5.50E+00 1.06E-02 1.15E-01 1.87 78.54535 10.077 4.50E+00 8.65E-03 9.72E-02 1.56 78.39462 10.102 3.50E+00 6.68E-03 7.93E-02 1.26 78.24471 10.099 2.50E+00 4.75E-03 6.09E-02 0.95 78.09583 10.079 1.50E+00 2.83E-03 4.19E-02 0.64 77.94386 10.095 5.00E-01 9.38E-04 2.19E-02 0.33 77.84467 10.088 9.65E-02 1.81E-04 1.04E-02 0.15 77.7956 14.604 3.30E-03 6.07E-06 5.44E-03 0.08

181 TABLE D-7 CARBON DIOXIDE IN [bmmim][PF6] (cont.)

25 oC 180 min Welton SS Bucket

Mass Sample Sample Gas Reading Temperature Pressure Density Mole Fraction (mg) (oC) (bar) (g / cm3) of Gas Wt % Gas 77.71786 24.962 0 3.21E-292 1.40E-291 2.06E-290 77.70487 25.077 0.0088 1.56E-05 -1.07E-03 -1.57E-02 77.70405 25.081 0.0503 8.93E-05 -8.16E-04 -1.20E-02 77.71642 25.07 0.1984 3.53E-04 0.001 0.02 77.75127 25.079 0.5993 1.07E-03 0.008 0.11 77.79127 25.073 0.9999 1.78E-03 0.014 0.21 77.88241 25.07 2.0005 3.59E-03 0.029 0.44 77.98263 25.073 3.0003 5.41E-03 0.045 0.68 78.08243 25.068 3.9998 7.25E-03 0.060 0.93 78.18161 25.077 5.0011 9.11E-03 0.074 1.17 78.27791 25.075 6 1.10E-02 0.088 1.41 78.37606 25.073 6.9987 1.29E-02 0.102 1.65 78.47092 25.073 8.0005 1.48E-02 0.115 1.88 78.56825 25.073 9.0014 1.68E-02 0.128 2.12 78.66393 25.081 10.0003 1.87E-02 0.141 2.36 78.76021 25.075 11.0014 2.07E-02 0.153 2.60 78.84661 25.075 12.0008 2.27E-02 0.165 2.83 78.93549 25.081 12.9999 2.48E-02 0.176 3.06 78.93549 25.077 13.001 2.48E-02 0.176 3.06 78.90456 25.084 12.5016 2.37E-02 0.171 2.96 78.82104 25.073 11.5012 2.17E-02 0.160 2.74 78.73362 25.081 10.5017 1.97E-02 0.149 2.51 78.64516 25.081 9.5017 1.77E-02 0.137 2.28 78.55545 25.07 8.5014 1.58E-02 0.124 2.05 78.4639 25.073 7.4999 1.38E-02 0.111 1.82 78.37255 25.077 6.4997 1.19E-02 0.098 1.58 78.27956 25.07 5.5009 1.00E-02 0.085 1.35 78.18532 25.07 4.5008 8.18E-03 0.071 1.11 78.09068 25.068 3.5006 6.33E-03 0.057 0.88 77.9952 25.077 2.5013 4.50E-03 0.042 0.64 77.89849 25.075 1.5005 2.68E-03 0.027 0.40 77.80013 25.073 0.5012 8.92E-04 0.011 0.16 77.74735 25.086 0.0968 1.72E-04 0.003 0.05 77.73209 25.04 0.0033 5.86E-06 1.26E-03 1.87E-02

182 TABLE D-7 CARBON DIOXIDE IN [bmmim][PF6] (cont.)

25 oC 180 min Welton SS Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 77.72776 28.986 0.0003 1.75E-06 7.63E-06 1.13E-04 77.71703 25.079 0.0108 1.92E-05 -8.53E-04 -1.26E-02 77.71745 25.075 0.047 8.35E-05 -5.36E-04 -7.90E-03 77.73106 25.081 0.1988 3.53E-04 1.82E-03 2.69E-02 77.7655 25.07 0.5996 1.07E-03 0.008 0.12 77.80426 25.075 1.0007 1.79E-03 0.014 0.21 77.89396 25.075 1.9996 3.59E-03 0.029 0.44 77.99273 25.073 3.0008 5.41E-03 0.045 0.68 78.09212 25.084 4.0009 7.25E-03 0.060 0.93 78.1913 25.081 4.9995 9.11E-03 0.074 1.17 78.28739 25.068 6.0001 1.10E-02 0.088 1.41 78.38554 25.075 6.9985 1.29E-02 0.102 1.65 78.48143 25.077 8.0009 1.48E-02 0.115 1.88 78.57443 25.077 9 1.68E-02 0.128 2.12 78.66722 25.07 10.0002 1.87E-02 0.140 2.35 78.7629 25.068 11.0003 2.07E-02 0.153 2.59 78.85177 25.075 12.0002 2.27E-02 0.165 2.82 78.94084 25.073 13.0007 2.48E-02 0.176 3.06 78.94084 25.051 12.9995 2.48E-02 0.176 3.06 78.90744 25.075 12.5013 2.37E-02 0.171 2.95 78.82496 25.07 11.4995 2.17E-02 0.160 2.73 78.73711 25.075 10.5005 1.97E-02 0.148 2.50 78.64887 25.066 9.501 1.77E-02 0.136 2.27 78.55833 25.077 8.4999 1.58E-02 0.124 2.04 78.46844 25.077 7.5013 1.39E-02 0.111 1.81 78.37627 25.07 6.5012 1.19E-02 0.098 1.58 78.28285 25.066 5.5008 1.00E-02 0.084 1.34 78.19109 25.068 4.5007 8.18E-03 0.071 1.11 78.0948 25.079 3.5007 6.33E-03 0.056 0.87 77.99892 25.077 2.5009 4.50E-03 0.041 0.63 77.90365 25.075 1.5003 2.68E-03 0.026 0.40 77.80447 25.073 0.5009 8.92E-04 0.010 0.16 77.75044 25.081 0.0968 1.72E-04 0.003 0.04 77.7356 25.055 0.0031 5.51E-06 7.07E-04 1.04E-02

183 TABLE D-7 CARBON DIOXIDE IN [bmmim][PF6] (cont.)

Solvent 25 oC 120 min Innovation Q4 Bucket

Mass Sample Sample Mole Reading Temperature Pressure Gas Density Fraction of Wt % (mg) (oC) (bar) (g / cm3) Gas Gas 53.54892 24.869 1.39E-03 2.46E-06 9.47E-06 0.00 53.54899 25.009 9.63E-03 1.71E-05 7.46E-05 0.00 53.55075 24.98 4.78E-02 8.50E-05 5.58E-04 0.01 53.55388 24.961 9.99E-02 1.78E-04 1.31E-03 0.02 53.57346 25.004 4.99E-01 8.89E-04 6.48E-03 0.10 53.60715 24.999 9.99E-01 1.78E-03 1.40E-02 0.21 53.70055 25.052 2.50E+00 4.49E-03 3.52E-02 0.54 53.82473 25.023 4.00E+00 7.25E-03 5.91E-02 0.92 53.95363 25.014 5.50E+00 1.00E-02 8.24E-02 1.31 54.08216 25.028 6.99E+00 1.29E-02 1.05E-01 1.70 54.21001 25.014 8.50E+00 1.58E-02 1.26E-01 2.09 54.3363 24.999 1.00E+01 1.87E-02 1.46E-01 2.47 54.42334 24.99 1.10E+01 2.07E-02 1.60E-01 2.73 54.50169 25.028 1.20E+01 2.27E-02 1.72E-01 2.98 54.5803 24.99 1.30E+01 2.48E-02 1.84E-01 3.22 54.5803 24.99 1.30E+01 2.48E-02 1.84E-01 3.22 54.5026 25.004 1.10E+01 2.07E-02 1.67E-01 2.87 54.37251 25.052 9.00E+00 1.68E-02 1.44E-01 2.43 54.14615 24.985 6.00E+00 1.10E-02 1.05E-01 1.71 54.02736 25.014 5.00E+00 9.11E-03 8.72E-02 1.39 53.90555 25.009 3.50E+00 6.32E-03 6.49E-02 1.01 53.77983 24.999 2.00E+00 3.59E-03 4.12E-02 0.63 53.65502 25.033 4.99E-01 8.88E-04 1.66E-02 0.25 53.58633 25.019 1.00E-02 1.78E-05 4.78E-03 0.07

184 TABLE D-7 CARBON DIOXIDE IN [bmmim][PF6] (cont.)

50 oC 90 min Welton SS Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 77.7094 50.031 0 3.21E-292 1.45E-291 2.13E-290 77.70219 50.019 0.0119 1.95E-05 -5.41E-04 -7.98E-03 77.70157 50.008 0.0499 8.18E-05 -3.14E-04 -4.64E-03 77.70405 50.026 0.1986 3.26E-04 1.00E-03 1.48E-02 77.7191 50.017 0.5999 9.85E-04 0.005 0.08 77.73869 50.017 1.0003 1.65E-03 0.010 0.15 77.78363 50.006 2.0009 3.30E-03 0.021 0.31 77.83086 50.026 2.9997 4.97E-03 0.032 0.48 77.87313 50.019 4.0012 6.66E-03 0.042 0.65 77.91087 50.019 5.001 8.36E-03 0.052 0.81 77.95644 50.019 6.001 1.01E-02 0.063 0.98 77.99294 50.004 7.0009 1.18E-02 0.072 1.14 78.04324 50.017 8.0007 1.35E-02 0.083 1.31 78.05995 50.026 9.0012 1.53E-02 0.090 1.45 78.12634 50.024 9.9998 1.70E-02 0.102 1.64 78.13748 50.019 11.0014 1.88E-02 0.109 1.77 78.15852 50.033 12.0017 2.06E-02 0.117 1.91 78.19604 50.017 13.0014 2.24E-02 0.126 2.08 78.19625 50.019 13.0024 2.25E-02 0.126 2.08 78.17151 50.028 12.5014 2.15E-02 0.121 1.99 78.16181 49.998 11.501 1.97E-02 0.114 1.86 78.1284 50.019 10.5006 1.79E-02 0.105 1.70 78.0948 50.026 9.5005 1.62E-02 0.096 1.55 78.05913 50.026 8.5004 1.44E-02 0.087 1.39 78.0183 50.01 7.5011 1.27E-02 0.078 1.22 77.99025 50.019 6.5006 1.09E-02 0.069 1.08 77.95232 50.019 5.5012 9.21E-03 0.059 0.92 77.90819 50.019 4.5006 7.50E-03 0.049 0.75 77.87808 50.019 3.5009 5.81E-03 0.039 0.60 77.84097 50.022 2.5007 4.14E-03 0.029 0.44 77.78363 50.006 1.5006 2.47E-03 0.017 0.26 77.74426 50.019 0.5008 8.22E-04 0.007 0.10 77.72364 50.019 0.097 1.59E-04 0.002 0.03 77.71828 50.068 0.0038 6.23E-06 8.02E-04 1.18E-02

185 TABLE D-7 CARBON DIOXIDE IN [bmmim][PF6] (cont.)

Solvent 50 oC 120 min Innovation Q4 Bucket

Mass Sample Sample Gas Reading Temperature Pressure Density Mole Fraction Wt % (mg) (oC) (bar) (g / cm3) of Gas Gas 53.5218 49.9474 7.50E-04 1.64E-06 6.55E-06 0.00 53.7482 49.9602 5.00E+00 8.35E-03 5.84E-02 0.91 53.6989 49.9773 1.00E+01 1.71E-02 8.31E-02 1.32 53.5793 49.9889 9.98E-01 1.64E-03 1.37E-02 0.20

TABLE D-8 CARBON DIOXIDE IN [emim][Tf2N]

10 oC 90 min Covalent SS Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction Wt % (mg) (oC) (bar) (g / cm3) of Gas Gas 65.73429 9.861 0.011966 2.24E-05 9.09E-05 1.02E-03 65.74364 9.986 0.047276 8.85E-05 1.62E-03 1.83E-02 65.75636 10.038 0.099074 1.85E-04 0.004 0.04 65.85346 9.986 0.499441 9.37E-04 0.020 0.22 65.97431 10.029 0.999281 1.88E-03 0.039 0.45 66.33426 10.043 2.497841 4.74E-03 0.091 1.12 66.70445 9.976 3.998324 7.66E-03 0.140 1.79 67.08124 9.976 5.498532 1.06E-02 0.184 2.47 67.08124 9.976 5.498532 1.06E-02 0.184 2.47 66.95817 10.014 4.998692 9.64E-03 0.170 2.25 66.21838 10.01 1.999237 3.78E-03 0.075 0.90 65.78331 9.962 0.19841 3.72E-04 0.008 0.09 65.75167 10.014 0.073244 1.37E-04 2.90E-03 0.03 65.73918 9.995 0.026942 5.04E-05 8.65E-04 9.74E-03

186 TABLE D-8 CARBON DIOXIDE IN [emim][Tf2N] (cont.)

25 oC 90 min Covalent SS Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density (g / Fraction of (mg) (oC) (bar) cm3) Gas Wt % Gas 65.73524 25.207 -0.000125 3.21E-292 1.32E-291 1.48E-290 65.73336 25.043 0.014989 2.66E-05 -1.45E-04 -1.63E-03 65.73975 25.023 0.048925 8.69E-05 9.67E-04 1.09E-02 65.74854 25.014 0.099074 1.76E-04 0.003 0.03 65.81451 24.995 0.498891 8.88E-04 0.014 0.16 65.89554 25.028 0.999281 1.78E-03 0.028 0.33 66.13827 25.014 2.498253 4.49E-03 0.068 0.81 66.38046 25.028 3.998461 7.25E-03 0.105 1.30 66.62229 25.004 5.498807 1.00E-02 0.139 1.78 66.87058 24.999 6.999015 1.29E-02 0.171 2.27 67.11539 25.019 8.498124 1.58E-02 0.201 2.75 67.35996 24.999 10.00026 1.87E-02 0.229 3.23 67.8076 24.956 12.80173 2.44E-02 0.276 4.10 67.83723 25.009 12.99834 2.48E-02 0.279 4.16 67.83723 25.009 12.99834 2.48E-02 0.279 4.16 67.51497 24.956 10.99801 2.07E-02 0.246 3.54 66.69999 25.004 5.999197 1.10E-02 0.149 1.94 66.06106 24.999 1.999237 3.59E-03 0.056 0.66 65.76679 25.048 0.198685 3.53E-04 0.006 0.06 65.7466 24.995 0.073656 1.31E-04 0.002 0.02 65.73397 24.99 0.023507 4.18E-05 1.90E-09 2.13E-08 65.73492 22.124 0.00015 1.79E-06 -3.59E-05 -4.04E-04

25 oC 90 min Covalent SS Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 65.73907 27.183 -0.000125 3.21E-292 1.32E-291 1.48E-290 65.73661 25.033 0.018561 3.30E-05 -1.97E-04 -2.22E-03 65.74288 25.019 0.048101 8.55E-05 8.66E-04 9.75E-03 65.75188 25.014 0.100036 1.78E-04 0.002 0.03 65.81728 25.004 0.499166 8.89E-04 0.014 0.16 65.89813 25.014 0.999007 1.78E-03 0.028 0.32 65.74039 25.192 0.00015 1.78E-06 0.000 0.00 65.73963 25.014 0.010043 1.78E-05 0.000 0.00 65.74586 25.004 0.048101 8.55E-05 0.001 0.01 65.89921 24.97 0.987053 1.76E-03 0.028 0.32 65.90079 25.009 0.999144 1.78E-03 0.028 0.33

187 TABLE D-8 CARBON DIOXIDE IN [emim][Tf2N] (cont.)

25 oC 90 min Wasserscheid SS Bucket (static)

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction (mg) (oC) (bar) (g / cm3) of Gas Wt % Gas 76.90508 25.134 0.0001 1.78E-06 7.76E-06 8.72E-05 76.90138 25.077 0.0142 2.52E-05 -3.18E-04 -3.57E-03 76.90138 25.081 0.0513 9.11E-05 -2.98E-05 -3.35E-04 76.93111 25.079 0.2007 3.57E-04 0.005 0.05 77.0042 25.075 0.6018 1.07E-03 0.016 0.18 77.07688 25.075 1.0026 1.79E-03 0.027 0.31 77.26747 25.081 2.0023 3.59E-03 0.054 0.64 77.45765 25.079 3.003 5.41E-03 0.081 0.97 77.64596 25.079 4.0031 7.25E-03 0.105 1.30 77.83242 25.07 5.003 9.11E-03 0.128 1.63 78.01702 25.081 6.003 1.10E-02 0.150 1.95 78.20348 25.068 7.0018 1.29E-02 0.171 2.27 78.38973 25.075 8.0026 1.48E-02 0.191 2.59 78.57475 25.077 9.002 1.68E-02 0.210 2.91 78.76017 25.075 10.0025 1.87E-02 0.229 3.22 78.94476 25.062 11.0023 2.07E-02 0.246 3.54 79.13206 25.075 12.0021 2.27E-02 0.263 3.86 79.31355 25.068 13.0028 2.48E-02 0.279 4.17 79.31355 25.101 13.0032 2.48E-02 0.279 4.17 79.22022 25.077 12.5033 2.37E-02 0.271 4.01 79.03603 25.075 11.5034 2.17E-02 0.254 3.70 78.84772 25.075 10.5028 1.97E-02 0.237 3.38 78.66003 25.07 9.5019 1.77E-02 0.219 3.06 78.47336 25.079 8.5025 1.58E-02 0.200 2.74 78.2871 25.077 7.5029 1.39E-02 0.181 2.42 78.10251 25.075 6.503 1.19E-02 0.160 2.10 77.91708 25.066 5.5027 1.01E-02 0.139 1.78 77.73166 25.075 4.5032 8.18E-03 0.116 1.46 77.54602 25.073 3.5022 6.33E-03 0.092 1.13 77.35792 25.07 2.5033 4.50E-03 0.067 0.80 77.17496 25.075 1.5027 2.69E-03 0.041 0.48 76.98665 25.073 0.5024 8.94E-04 0.013 0.15 76.91004 25.081 0.0989 1.76E-04 1.34E-03 1.51E-02 76.89558 25.23 0.004 7.10E-06 -1.07E-03 -1.20E-02

188 TABLE D-8 CARBON DIOXIDE IN [emim][Tf2N] (cont.)

25 oC 90 min Wasserscheid SS Bucket (flowing)

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 76.87865 25.051 0.0501 8.90E-05 -0.00267 -0.03 76.9057 25.081 0.1985 3.53E-04 0.001611 0.018137 76.98025 25.079 0.5996 1.07E-03 0.013 0.15 77.05562 25.075 1.0006 1.79E-03 0.025 0.28 77.24249 25.077 2.001 3.59E-03 0.052 0.61 77.42998 25.062 3.0004 5.41E-03 0.078 0.94 77.6152 25.068 4.0017 7.25E-03 0.102 1.26 77.79959 25.07 5.0013 9.11E-03 0.125 1.59 77.98625 25.073 6.0017 1.10E-02 0.148 1.91 78.17354 25.066 7.0012 1.29E-02 0.169 2.23 78.36165 25.068 8.0023 1.48E-02 0.189 2.55 78.5479 25.066 9.0019 1.68E-02 0.208 2.87 78.73477 25.073 10.0016 1.87E-02 0.227 3.19 78.92267 25.07 11.0021 2.07E-02 0.245 3.51 79.1081 25.075 12.0024 2.27E-02 0.262 3.83 79.29332 25.075 13.0019 2.48E-02 0.278 4.14 79.29332 25.126 13.0012 2.48E-02 0.278 4.14 79.21362 25.064 12.5021 2.37E-02 0.270 4.00 79.02715 25.077 11.5018 2.17E-02 0.254 3.69 78.83905 25.068 10.5016 1.97E-02 0.237 3.37 78.65176 25.075 9.5015 1.77E-02 0.218 3.05 78.4653 25.081 8.5021 1.58E-02 0.200 2.73 78.27967 25.07 7.5017 1.39E-02 0.180 2.41 78.0957 25.086 6.5014 1.19E-02 0.160 2.09 77.91068 25.077 5.5012 1.00E-02 0.138 1.77 77.72649 25.073 4.5016 8.18E-03 0.116 1.45 77.54252 25.079 3.5011 6.33E-03 0.092 1.13 77.35647 25.079 2.5001 4.50E-03 0.067 0.80 77.17249 25.075 1.5006 2.68E-03 0.041 0.48 76.98541 25.075 0.5004 8.91E-04 0.013 0.15 76.90901 25.077 0.0994 1.77E-04 1.22E-03 1.38E-02 76.88671 25.075 0.0188 3.34E-05 -1.98E-03 -2.23E-02

189 TABLE D-8 CARBON DIOXIDE IN [emim][Tf2N] (cont.)

50 oC 90 min Covalent SS Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction Wt % (mg) (oC) (bar) (g / cm3) of Gas Gas 65.73647 46.971 0.021721 3.59E-05 1.51E-04 1.70E-03 65.73884 50.047 0.048101 7.88E-05 6.52E-04 7.34E-03 65.74423 50.018 0.100448 1.65E-04 1.74E-03 0.02 65.77944 49.984 0.498754 8.19E-04 0.009 0.10 65.82362 50.018 0.999281 1.64E-03 0.018 0.21 65.95847 49.989 2.498253 4.13E-03 0.045 0.53 66.06537 50.037 3.998599 6.65E-03 0.068 0.81 66.20336 49.994 5.498944 9.21E-03 0.092 1.13 66.20336 49.994 5.498944 9.21E-03 0.092 1.13 66.17967 49.95 4.999516 8.35E-03 0.087 1.06 65.92441 49.732 1.999237 3.30E-03 0.038 0.44 65.75664 49.974 0.19841 3.25E-04 0.004 0.05 65.74445 50.018 0.073244 1.20E-04 1.58E-03 1.78E-02 65.73859 49.989 0.021858 3.58E-05 4.37E-04 4.92E-03

TABLE D-9 CARBON DIOXIDE IN [emmim][Tf2N]

10 oC 90 min Covalent SS Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of Wt % (mg) (oC) (bar) (g / cm3) Gas Gas 72.54586 14.978 0.021996 4.04E-05 1.82E-04 1.97E-03 72.55145 10.221 0.047826 8.94E-05 1.11E-03 1.21E-02 72.56258 9.99 0.099074 1.85E-04 0.003 0.03 72.64482 10.077 0.498617 9.32E-04 0.016 0.18 72.75104 10.024 0.998045 1.87E-03 0.033 0.37 73.07201 9.899 2.499215 4.68E-03 0.081 0.94 73.39652 9.899 4.012063 7.51E-03 0.124 1.52 73.73341 9.88 5.497295 1.03E-02 0.165 2.09 73.73341 9.88 5.497295 1.03E-02 0.165 2.09 73.62546 10.058 4.999791 9.35E-03 0.152 1.91 72.98361 10.029 1.997726 3.74E-03 0.067 0.78 72.59686 9.995 0.198273 3.71E-04 0.008 0.09 72.55962 10.029 0.073381 1.37E-04 0.002 0.03 72.54755 10.029 0.021858 4.09E-05 3.98E-04 4.32E-03

190 TABLE D-9 CARBON DIOXIDE IN [emmim][Tf2N] (cont.)

25 oC 90 min Covalent SS Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 72.55401 31.964 2.88E-04 5.00E-07 2.27E-06 0.00 72.55228 24.999 1.77E-02 3.15E-05 -7.64E-05 0.00 72.55798 25.014 4.91E-02 8.71E-05 9.00E-04 0.01 72.56554 25.014 1.00E-01 1.78E-04 2.27E-03 0.02 72.6226 25.014 4.98E-01 8.85E-04 1.26E-02 0.14 72.69396 25.004 9.98E-01 1.77E-03 2.52E-02 0.28 72.90704 24.985 2.50E+00 4.43E-03 6.10E-02 0.70 73.11938 25.028 4.00E+00 7.09E-03 9.43E-02 1.12 73.33573 24.99 5.50E+00 9.76E-03 1.26E-01 1.54 73.54907 25.033 6.99E+00 1.24E-02 1.55E-01 1.95 73.76546 24.932 8.50E+00 1.51E-02 1.82E-01 2.36 74.1795 24.985 1.14E+01 2.03E-02 2.30E-01 3.14 74.17942 25.038 1.15E+01 2.04E-02 2.30E-01 3.15 74.25783 24.98 1.20E+01 2.13E-02 2.38E-01 3.29 74.31239 25.023 1.24E+01 2.20E-02 2.44E-01 3.39 74.39793 24.98 1.30E+01 2.31E-02 2.53E-01 3.55 74.39793 24.98 1.30E+01 2.31E-02 2.53E-01 3.55 74.11474 24.975 1.10E+01 1.95E-02 2.23E-01 3.02 73.40171 25.043 6.00E+00 1.07E-02 1.35E-01 1.67 72.83778 25.014 2.00E+00 3.55E-03 4.96E-02 0.56 72.57785 25.028 1.99E-01 3.53E-04 4.61E-03 0.05 72.55883 24.99 7.27E-02 1.29E-04 1.20E-03 0.01 72.55215 25.004 0.023645 4.20E-05 -4.51E-05 -4.90E-04

25 oC 90 min Covalent SS Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction (mg) (oC) (bar) (g / cm3) of Gas Wt % Gas 72.54247 32.476 0.000288 4.99E-07 2.27E-06 2.46E-05 72.54082 24.98 0.011554 2.05E-05 -1.16E-04 -1.26E-03 72.54636 24.98 0.047414 8.42E-05 8.76E-04 9.52E-03 72.55386 24.995 0.098112 1.74E-04 2.23E-03 0.02 72.61098 25.033 0.501639 8.91E-04 1.26E-02 0.14 72.68244 25.014 0.999281 1.77E-03 2.52E-02 0.28 72.89581 25.004 2.51584 4.47E-03 6.12E-02 0.70 73.11006 25.009 4.004781 7.11E-03 9.46E-02 1.12 73.32369 25.028 5.48864 9.75E-03 1.26E-01 1.53

191 TABLE D-9 CARBON DIOXIDE IN [emmim][Tf2N] (cont.)

25 oC 90 min Wasserscheid SS Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 75.56805 25.457 0 3.21E-292 1.48E-291 1.61E-290 75.55422 25.101 0.0135 2.40E-05 -1.58E-03 -1.71E-02 75.55422 25.075 0.0507 9.01E-05 -1.27E-03 -1.38E-02 75.57384 25.079 0.1996 3.55E-04 0.002 0.03 75.63104 25.081 0.6006 1.07E-03 0.012 0.14 75.69133 25.075 1.0012 1.79E-03 0.023 0.25 75.84351 25.075 2.0024 3.59E-03 0.048 0.54 75.99218 25.077 3.0013 5.41E-03 0.071 0.83 76.14064 25.077 4.0011 7.25E-03 0.094 1.11 76.28911 25.075 5.0022 9.11E-03 0.115 1.39 76.4384 25.07 6.0023 1.10E-02 0.136 1.67 76.58769 25.073 7.0026 1.29E-02 0.155 1.96 76.7376 25.068 8.0025 1.48E-02 0.174 2.24 76.8873 25.075 9.0026 1.68E-02 0.192 2.52 77.03763 25.075 10.0015 1.87E-02 0.210 2.80 77.18629 25.079 11.0026 2.07E-02 0.227 3.08 77.33207 25.075 12.0019 2.27E-02 0.242 3.36 77.47929 25.079 13.0028 2.48E-02 0.258 3.63 77.47929 25.108 13.0039 2.48E-02 0.258 3.63 77.40991 25.073 12.5032 2.37E-02 0.250 3.50 77.26186 25.077 11.503 2.17E-02 0.235 3.22 77.11382 25.075 10.5023 1.97E-02 0.218 2.94 76.96452 25.068 9.5024 1.77E-02 0.201 2.66 76.81545 25.075 8.5023 1.58E-02 0.184 2.38 76.6676 25.081 7.5025 1.39E-02 0.165 2.10 76.52098 25.073 6.5015 1.19E-02 0.146 1.83 76.37273 25.075 5.5021 1.01E-02 0.126 1.54 76.22509 25.073 4.5024 8.18E-03 0.105 1.26 76.07951 25.068 3.502 6.33E-03 0.084 0.98 75.9325 25.073 2.5019 4.50E-03 0.061 0.70 75.78507 25.077 1.5009 2.69E-03 0.037 0.42 75.63268 25.073 0.5024 8.94E-04 0.012 0.13 75.57362 25.081 0.0982 1.74E-04 1.48E-03 1.61E-02 75.56165 25.488 0.0035 6.21E-06 -7.52E-04 -8.16E-03

192 TABLE D-9 CARBON DIOXIDE IN [emmim][Tf2N] (cont.)

50 oC 90 min Covalent SS Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of Wt % (mg) (oC) (bar) (g / cm3) Gas Gas 72.54224 47.485 1.30E-05 2.15E-08 9.97E-08 0.00 72.54312 49.999 1.00E-02 1.65E-05 1.88E-04 0.00 72.54645 50.018 4.71E-02 7.72E-05 8.93E-04 0.01 72.55068 49.994 9.87E-02 1.62E-04 1.82E-03 0.02 72.58115 49.979 4.98E-01 8.17E-04 8.66E-03 0.09 72.62072 49.994 9.98E-01 1.64E-03 1.73E-02 0.19 72.72314 49.979 2.49E+00 4.09E-03 4.03E-02 0.45 72.8522 50.037 4.00E+00 6.55E-03 6.52E-02 0.75 72.94971 49.979 5.49E+00 8.99E-03 8.55E-02 1.01 72.94971 49.979 5.49E+00 8.99E-03 8.55E-02 1.01 72.87887 49.999 5.01E+00 8.20E-03 7.48E-02 0.87 72.88844 50.013 4.69E+00 7.68E-03 7.38E-02 0.86 72.56042 50.003 1.98E-01 3.25E-04 3.80E-03 0.04 72.54819 49.999 7.28E-02 1.19E-04 1.31E-03 0.01 72.54408 50.018 2.14E-02 3.51E-05 3.97E-04 0.00

193 TABLE D-10 CARBON DIOXIDE IN [MeBuPyrr][Tf2N]

10 oC 90 min Neta Q1 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of Wt % (mg) (oC) (bar) (g / cm3) Gas Gas 79.29511 11.838 0.022545 4.19E-05 1.07E-04 1.20E-03 79.29761 10.158 0.05181 9.69E-05 5.27E-04 5.93E-03 79.30821 10.149 0.098937 1.85E-04 1.94E-03 0.022 79.38007 10.014 0.499029 9.36E-04 0.012 0.13 79.49729 9.875 0.999968 1.88E-03 0.027 0.31 79.83124 10.163 2.498665 4.74E-03 0.067 0.81 80.26686 10.053 3.998049 7.66E-03 0.114 1.42 80.73273 10.014 5.502242 1.06E-02 0.159 2.07 81.21191 10.067 6.99819 1.37E-02 0.200 2.73 81.7007 9.995 8.498812 1.68E-02 0.238 3.40 82.18835 9.966 9.998058 1.99E-02 0.273 4.05 82.54935 10.019 10.99898 2.21E-02 0.296 4.52 83.02369 9.952 12.00017 2.43E-02 0.324 5.12 83.22673 10.408 12.99724 2.64E-02 0.337 5.41 83.22673 10.408 12.99724 2.64E-02 0.337 5.41 82.74361 10.187 10.99856 2.21E-02 0.307 4.75 81.23637 9.928 5.998785 1.16E-02 0.198 2.71 80.0636 9.933 1.999237 3.79E-03 0.087 1.07 79.52804 9.981 0.198273 3.71E-04 0.026 0.30 79.40803 10.01 0.073107 1.37E-04 0.013 0.15 79.35766 10.038 0.023507 4.40E-05 0.007 0.08

194 TABLE D-10 CARBON DIOXIDE IN [MeBuPyrr][Tf2N] (cont.)

25 oC 90 min Neta Q1 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 79.30186 29.778 0.000425 1.75E-06 4.58E-06 5.15E-05 79.29991 24.898 0.012378 2.20E-05 -1.61E-04 -1.81E-03 79.30601 25.033 0.048101 8.54E-05 6.89E-04 7.75E-03 79.31543 25.014 0.098937 1.76E-04 0.002 0.02 79.37878 25.038 0.499441 8.89E-04 0.011 0.12 79.47263 24.98 0.999281 1.78E-03 0.023 0.27 79.74153 25.004 2.498116 4.49E-03 0.058 0.68 80.05209 25.023 3.998186 7.25E-03 0.093 1.15 80.37084 25.057 5.497845 1.00E-02 0.128 1.62 80.69289 25.052 6.99819 1.29E-02 0.160 2.09 81.01263 25.033 8.498398 1.58E-02 0.189 2.56 81.33318 25.048 9.998194 1.87E-02 0.217 3.02 81.55805 24.946 10.99911 2.07E-02 0.235 3.34 81.76827 25.014 12.00017 2.27E-02 0.252 3.64 81.97678 24.956 12.99737 2.48E-02 0.267 3.94 81.97678 24.956 12.99737 2.48E-02 0.267 3.94 81.62614 25.023 10.99801 2.07E-02 0.240 3.42 80.59698 24.999 5.999197 1.10E-02 0.148 1.92 79.77212 25.019 1.999787 3.59E-03 0.059 0.69 79.3849 24.98 0.198547 3.53E-04 0.010 0.11 79.32328 25.028 0.073107 1.30E-04 0.003 0.03 79.30057 25.033 0.022408 3.98E-05 -4.03E-05 -4.54E-04

195 TABLE D-10 CARBON DIOXIDE IN [MeBuPyrr][Tf2N] (cont.)

50 oC 90 min Neta Q1 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 79.31327 45.894 0.024057 3.99E-05 1.10E-04 1.23E-03 79.31036 50.028 0.047963 7.86E-05 -1.11E-04 -1.24E-03 79.31645 49.984 0.099211 1.63E-04 8.02E-04 9.02E-03 79.36302 50.003 0.499853 8.21E-04 0.008 0.09 79.42525 50.052 0.999281 1.64E-03 0.017 0.19 79.59367 50.003 2.497704 4.13E-03 0.041 0.48 79.79382 49.989 3.998324 6.65E-03 0.067 0.80 79.97849 49.965 5.498532 9.21E-03 0.091 1.11 80.16501 49.965 6.998877 1.18E-02 0.113 1.42 80.3413 50.028 8.49785 1.44E-02 0.134 1.71 80.5333 50.018 9.998882 1.70E-02 0.155 2.02 80.63998 49.979 10.99898 1.88E-02 0.167 2.20 80.74702 50.018 12.00017 2.06E-02 0.179 2.39 80.89066 49.969 13.0004 2.25E-02 0.193 2.61 80.89066 49.969 13.0004 2.25E-02 0.193 2.61 80.64715 49.994 10.99856 1.88E-02 0.168 2.21 80.06337 50.052 6.00057 1.01E-02 0.100 1.24 79.56763 49.989 1.999787 3.30E-03 0.036 0.42 79.33598 50.033 0.198685 3.26E-04 0.003 0.04 79.31146 50.028 0.073381 1.20E-04 1.27E-04 1.43E-03 79.30463 50.003 0.022545 3.69E-05 -8.68E-04 -9.75E-03

196 TABLE D-11 CARBON DIOXIDE IN [HeBu3N][Tf2N]

10 oC 180 min Neta Q1 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of Wt % (mg) (oC) (bar) (g / cm3) Gas Gas 77.61482 12.025 0.021584 4.01E-05 1.43E-04 1.60E-03 77.61382 10.091 0.046727 8.74E-05 1.96E-04 2.21E-03 77.61778 10.091 0.099074 1.85E-04 9.98E-04 1.12E-02 77.66061 10.029 0.500403 9.39E-04 0.009 0.10 77.73425 9.986 0.999007 1.88E-03 0.020 0.23 77.94118 9.986 2.497841 4.74E-03 0.051 0.61 78.2344 10.034 3.998049 7.66E-03 0.089 1.09 78.5714 10.014 5.499082 1.06E-02 0.129 1.63 78.93074 10.019 7.002313 1.37E-02 0.166 2.19 79.30261 9.832 8.497024 1.68E-02 0.202 2.77 79.67859 9.89 9.997646 1.99E-02 0.235 3.34 79.96555 9.87 10.99746 2.21E-02 0.258 3.77 80.23366 9.962 11.99934 2.43E-02 0.279 4.16 80.5024 9.947 13.00328 2.65E-02 0.298 4.56 80.5024 9.947 13.00328 2.65E-02 0.298 4.56 80.22952 10.091 10.99939 2.21E-02 0.274 4.08 79.28585 10.005 5.998922 1.16E-02 0.189 2.55 78.50885 9.995 1.999512 3.78E-03 0.104 1.29 78.0455 10.062 0.19841 3.71E-04 0.048 0.57 77.84338 10.034 0.073656 1.38E-04 0.026 0.30 77.73544 9.981 0.022271 4.17E-05 0.014 0.16

197 TABLE D-11 CARBON DIOXIDE IN [HeBu3N][Tf2N] (cont.)

10 oC 90 min Neta Q1 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 77.7146 11.78 0.021446 3.99E-05 1.42E-04 1.60E-03 77.69196 9.88 0.054421 1.02E-04 -2.23E-03 -2.51E-02 77.67522 10.034 0.098937 1.85E-04 -3.86E-03 -4.33E-02 77.67661 10.024 0.499166 9.36E-04 -1.01E-03 -1.14E-02 77.70133 9.909 0.998869 1.88E-03 0.005 0.06 77.80373 9.952 2.498802 4.75E-03 0.026 0.30 77.98072 9.861 3.998736 7.67E-03 0.055 0.65 78.22084 9.938 5.498807 1.06E-02 0.087 1.07 78.51661 9.957 6.999427 1.37E-02 0.123 1.56 78.84908 10.115 8.498536 1.68E-02 0.159 2.09 79.2056 9.918 9.99792 1.99E-02 0.195 2.65 79.52288 9.899 10.99911 2.21E-02 0.222 3.11 79.82393 9.875 11.99797 2.43E-02 0.247 3.56 80.12285 9.938 12.99902 2.65E-02 0.270 3.99 80.12285 9.938 12.99902 2.65E-02 0.270 3.99 80.13088 9.928 10.99843 2.21E-02 0.262 3.84 79.63168 10.096 5.998922 1.16E-02 0.207 2.85 78.95831 10.158 1.999649 3.78E-03 0.135 1.72 78.52776 10.058 0.198685 3.72E-04 0.086 1.05 78.30943 10.029 0.073381 1.37E-04 0.064 0.77 78.15279 9.981 0.023507 4.40E-05 0.048 0.56

198 TABLE D-11 CARBON DIOXIDE IN [HeBu3N][Tf2N] (cont.)

25 oC 180 min Neta Q1 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of Wt % (mg) (oC) (bar) (g / cm3) Gas Gas 77.59383 26.137 0.000975 1.77E-06 6.42E-06 7.22E-05 77.59496 25.004 0.009081 1.61E-05 1.88E-04 2.11E-03 77.59975 25.009 0.046452 8.25E-05 9.77E-04 1.10E-02 77.60651 25.028 0.098937 1.76E-04 0.002 0.02 77.65144 25.019 0.499029 8.89E-04 0.010 0.11 77.71797 24.99 0.999968 1.79E-03 0.020 0.23 77.90381 25.014 2.497978 4.49E-03 0.049 0.58 78.13014 25.019 3.999423 7.25E-03 0.081 0.98 78.36706 25.009 5.498532 1.00E-02 0.111 1.39 78.61172 25.014 6.99874 1.29E-02 0.141 1.80 78.85011 25.028 8.498674 1.58E-02 0.168 2.21 79.09146 25.043 9.998882 1.87E-02 0.193 2.62 79.26612 24.97 10.99898 2.07E-02 0.211 2.91 79.4327 25.019 11.99797 2.27E-02 0.227 3.19 79.5927 24.98 12.99806 2.48E-02 0.242 3.46 79.5927 24.98 12.99806 2.48E-02 0.242 3.46 79.3624 24.98 10.99719 2.07E-02 0.217 3.03 78.64735 25.023 5.998647 1.10E-02 0.138 1.77 78.06265 25.004 1.999649 3.59E-03 0.063 0.75 77.74596 25.009 0.19841 3.53E-04 0.018 0.21 77.65156 25.009 0.072832 1.29E-04 0.007 0.08 77.61742 25.009 0.030789 5.47E-05 0.003 0.03

199 TABLE D-11 CARBON DIOXIDE IN [HeBu3N][Tf2N] (cont.)

25 oC 90 min Neta Q1 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 77.5881 33.399 0.000562 1.73E-06 6.27E-06 7.05E-05 77.5856 24.778 0.012516 2.22E-05 -2.06E-04 -2.31E-03 77.58749 25.028 0.047826 8.50E-05 2.38E-04 2.68E-03 77.59183 25.014 0.099074 1.76E-04 1.07E-03 1.20E-02 77.61331 25.028 0.499166 8.89E-04 0.006 0.07 77.65474 25.009 0.999144 1.78E-03 0.014 0.16 77.77321 25.009 2.498116 4.49E-03 0.036 0.42 77.94888 25.028 3.998186 7.25E-03 0.063 0.76 78.15714 24.99 5.498532 1.00E-02 0.092 1.13 78.39202 25.028 7.000938 1.29E-02 0.122 1.54 78.63221 25.023 8.498124 1.58E-02 0.150 1.95 78.88042 25.004 10.00039 1.87E-02 0.178 2.37 79.08038 25.004 10.99884 2.07E-02 0.198 2.69 79.26022 25.004 11.99879 2.27E-02 0.215 2.99 79.4315 24.985 12.99944 2.48E-02 0.232 3.28 79.4315 24.985 12.99944 2.48E-02 0.232 3.28 79.4015 25.033 10.99911 2.07E-02 0.221 3.08 78.89613 25.014 5.998785 1.10E-02 0.160 2.09 78.32323 25.019 1.9991 3.59E-03 0.089 1.08 77.99387 25.019 0.198273 3.53E-04 0.046 0.53 77.84714 25.014 0.072145 1.28E-04 0.029 0.34 77.75652 25.019 0.035873 6.37E-05 0.019 0.22

200 TABLE D-11 CARBON DIOXIDE IN [HeBu3N][Tf2N] (cont.)

50 oC 90 min Neta Q1 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of Wt % (mg) (oC) (bar) (g / cm3) Gas Gas 77.84126 45.618 0.023782 3.95E-05 1.49E-04 1.67E-03 77.67877 49.824 0.047002 7.71E-05 -0.019 -0.21 77.62807 50.018 0.098799 1.62E-04 -0.024 -0.27 77.62831 49.979 0.499029 8.19E-04 -0.022 -0.24 77.65652 50.018 0.999556 1.64E-03 -0.015 -0.17 77.7445 50.086 2.498528 4.13E-03 0.005 0.05 77.88032 50.008 3.998599 6.65E-03 0.029 0.33 78.01861 50.028 5.499082 9.21E-03 0.052 0.61 78.15511 49.974 6.998466 1.18E-02 0.074 0.89 78.29137 50.047 8.502108 1.44E-02 0.096 1.17 78.43979 50.008 10.00163 1.71E-02 0.117 1.47 78.52679 50.008 10.99952 1.88E-02 0.130 1.65 78.60365 49.989 11.99934 2.06E-02 0.142 1.82 78.7274 50.023 13.00108 2.24E-02 0.157 2.05 78.7274 50.023 13.00108 2.24E-02 0.157 2.05 78.62293 49.984 10.9987 1.88E-02 0.138 1.77 78.24678 49.994 5.998647 1.01E-02 0.078 0.94 77.89017 50.008 1.999374 3.30E-03 0.018 0.20 77.69896 50.013 0.198273 3.25E-04 -0.015 -0.17 77.63633 50.013 0.073656 1.21E-04 -0.023 -0.26 77.60886 50.042 0.02653 4.35E-05 -0.027 -0.30

201 TABLE D-12 CARBON DIOXIDE IN [MeBu3N][Tf2N]

25 oC 90 min Neta SS Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density (g / Fraction of (mg) (oC) (bar) cm3) Gas Wt % Gas 70.33318 25.515 0.001249 2.21E-06 1.19E-05 1.33E-04 70.33203 25.004 0.011691 2.08E-05 -3.41E-05 -3.84E-04 70.33661 24.975 0.047276 8.40E-05 8.83E-04 9.94E-03 70.3425 25.014 0.098937 1.76E-04 2.12 E-03 0.02 70.38548 25.028 0.498479 8.88E-04 0.011 0.13 70.44097 25.028 0.99832 1.78E-03 0.023 0.26 70.6007 24.995 2.497429 4.49E-03 0.055 0.65 70.76513 24.99 3.999423 7.25E-03 0.085 1.04 70.92442 25.028 5.498395 1.00E-02 0.114 1.43 70.92442 25.028 5.498395 1.00E-02 0.114 1.43 70.873 24.995 4.994845 9.10E-03 0.105 1.30 70.54899 25.004 1.998825 3.59E-03 0.044 0.52 70.34785 25.048 0.19841 3.53E-04 0.004 0.04 70.33063 24.999 0.07558 1.34E-04 3.97E-04 4.47E-03

TABLE D-13 CARBON DIOXIDE IN [iBuMeP][TOS]

50 oC 180 min Cytec SS Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density (g / Fraction (mg) (oC) (bar) cm3) of Gas Wt % Gas 69.80267 50.019 0.0002 1.64E-06 1.10E-05 1.25E-04 69.80267 50.019 0.0111 1.82E-05 1.22E-04 1.39E-03 69.80226 50.019 0.0472 7.74E-05 4.69E-04 5.31E-03 69.80123 50.019 0.1983 3.25E-04 0.002 0.02 69.79896 50.024 0.5987 9.83E-04 0.006 0.07 69.79896 50.008 1.0002 1.65E-03 0.010 0.12 69.80638 50.019 1.9992 3.30E-03 0.022 0.26 69.80721 50.017 2.9993 4.97E-03 0.033 0.38 69.78742 50.026 4.0002 6.66E-03 0.041 0.48 69.77752 50.019 5.0005 8.35E-03 0.050 0.60 69.78329 50.019 5.9984 1.01E-02 0.061 0.73 69.78204 50.022 6.9996 1.18E-02 0.071 0.86 69.77793 50.019 7.9998 1.35E-02 0.081 0.99 69.7604 50.026 8.9992 1.53E-02 0.089 1.09 69.75111 50.022 9.9998 1.70E-02 0.098 1.21 69.72576 50.031 11.0007 1.88E-02 0.105 1.31 69.70143 50.019 12.0009 2.06E-02 0.112 1.41 69.7006 50.024 12.9992 2.24E-02 0.121 1.54

202 TABLE D-13 CARBON DIOXIDE IN [iBuMeP][TOS] (cont.)

69.70081 50.008 12.9997 2.24E-02 0.121 1.54 69.6973 50.015 12.5008 2.15E-02 0.116 1.47 69.71462 50.022 11.4992 1.97E-02 0.108 1.36 69.7371 50.019 10.4995 1.79E-02 0.101 1.26 69.74885 50.006 9.4999 1.62E-02 0.093 1.14 69.75339 50.022 8.5009 1.44E-02 0.083 1.02 69.76762 50.013 7.5009 1.27E-02 0.075 0.91 69.77545 50.028 6.5009 1.09E-02 0.066 0.79 69.78061 50.024 5.5001 9.21E-03 0.056 0.67 69.79092 50.024 4.5002 7.50E-03 0.047 0.55 69.80557 50.019 3.5003 5.81E-03 0.038 0.45 69.81154 50.017 2.5005 4.14E-03 0.028 0.33 69.81051 50.019 1.499 2.47E-03 0.017 0.20 69.80783 50.019 0.5003 8.21E-04 0.006 0.07 69.80803 50.015 0.096 1.57E-04 1.73E-03 1.97E-02 69.80906 50.074 0.0034 5.57E-06 8.45E-04 9.58E-03

TABLE D-14 ETHANE IN [bmim][Tf2N]

10 oC 90 min Covalent Q1 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 51.7224 11.334 0.031339 3.98E-05 2.30E-05 1.65E-04 51.72027 10.307 0.047002 6.00E-05 -5.40E-04 -3.87E-03 51.71922 10.12 0.098937 1.26E-04 -7.86E-04 -5.63E-03 51.72955 10.153 0.499578 6.40E-04 2.29E-03 1.65E-02 51.74873 9.918 0.998732 1.29E-03 0.008 0.06 51.80115 9.899 2.497566 3.27E-03 0.023 0.17 51.86309 9.952 3.998049 5.30E-03 0.039 0.29 51.92503 9.952 5.497433 7.40E-03 0.056 0.42 51.98711 10.005 6.998466 9.57E-03 0.071 0.55 52.04709 9.99 8.494689 1.18E-02 0.086 0.67 52.10301 10.034 9.998744 1.41E-02 0.100 0.79 52.14662 9.827 10.99733 1.57E-02 0.110 0.88 52.18396 9.832 11.99687 1.74E-02 0.119 0.95 52.21817 9.861 13.00191 1.91E-02 0.126 1.03 52.21817 9.861 13.00191 1.91E-02 0.126 1.03 52.17736 10.264 10.9954 1.57E-02 0.116 0.94 52.00889 10.077 6.000159 8.12E-03 0.076 0.58 51.84087 9.866 1.999512 2.60E-03 0.032 0.24 51.75515 9.947 0.198273 2.54E-04 0.009 0.06 51.73697 9.986 0.073381 9.38E-05 0.004 0.03 51.72854 9.99 0.021446 2.74E-05 1.67E-03 1.20E-02

203

TABLE D-14 ETHANE IN [bmim][Tf2N] (cont.)

25 oC 90 min Covalent Q1 Bucket

Mass Sample Sample Mole Reading Temperature Pressure Gas Density Fraction (mg) (oC) (bar) (g / cm3) of Gas Wt % Gas 51.70473 31.819 0.000425 5.04E-07 3.35E-07 2.40E-06 51.70221 25.052 0.011142 1.35E-05 -6.71E-04 -4.81E-03 51.70307 25.004 0.047963 5.82E-05 -4.09E-04 -2.93E-03 51.70525 25.038 0.098937 1.20E-04 2.20E-04 1.58E-03 51.71778 25.004 0.498754 6.07E-04 0.004 0.03 51.73586 25.043 0.998732 1.22E-03 0.009 0.07 51.78402 25.014 2.497978 3.09E-03 0.023 0.17 51.83563 25.019 4.002995 5.01E-03 0.037 0.28 51.88548 25.019 5.498669 6.97E-03 0.051 0.38 51.93726 25.033 6.99929 8.99E-03 0.064 0.49 51.98491 25.014 8.497438 1.11E-02 0.077 0.59 52.0294 25.019 9.995447 1.32E-02 0.088 0.69 52.06324 25.023 10.9976 1.46E-02 0.096 0.76 52.09479 25.004 12.00498 1.61E-02 0.104 0.82 52.12051 25.009 12.99064 1.76E-02 0.110 0.88 52.12051 25.009 12.99064 1.76E-02 0.110 0.88 52.08047 24.966 10.99417 1.46E-02 0.100 0.79 51.94461 25.043 5.997686 7.63E-03 0.065 0.50 51.81275 25.023 1.999374 2.46E-03 0.030 0.22 51.74413 25.019 0.197998 2.40E-04 0.011 0.08 51.73214 25.023 0.073107 8.87E-05 7.40E-03 5.34E-02 51.72524 25.028 0.021721 2.84E-05 5.52E-03 3.98E-02

204 TABLE D-14 ETHANE IN [bmim][Tf2N] (cont.)

25 oC 90 min Covalent Q1 Bucket

Mass Sample Sample Mole Reading Temperature Pressure Gas Density Fraction (mg) (oC) (bar) (g / cm3) of Gas Wt % Gas 51.70099 33.244 0.000837 9.88E-07 6.56E-07 4.70E-06 51.69744 25.072 0.011416 1.38E-05 -9.50E-04 -6.80E-03 51.69879 25.023 0.054283 6.58E-05 -5.50E-04 -3.94E-03 51.70116 25.043 0.098662 1.20E-04 1.25E-04 8.98E-04 51.7134 24.975 0.498754 6.07E-04 0.0037 0.03 51.73229 25.033 1.000243 1.22E-03 0.0092 0.07 51.77945 25.038 2.498802 3.09E-03 0.0227 0.17 51.83099 24.999 3.998324 5.01E-03 0.0370 0.27 51.88157 25.038 5.499219 6.97E-03 0.0507 0.38 51.93149 24.966 6.996267 8.99E-03 0.0638 0.49 51.98004 25.009 8.498948 1.11E-02 0.0763 0.59 52.0259 25.004 9.997508 1.32E-02 0.0880 0.69 52.05921 24.999 11.00104 1.47E-02 0.0962 0.76 52.09207 24.99 11.99302 1.61E-02 0.1041 0.83

205 TABLE D-14 ETHANE IN [bmim][Tf2N] (cont.)

50 oC 90 min Covalent Q1 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 51.72468 46.209 0.032987 3.74E-05 3.08E-05 2.21E-04 51.72079 50.042 0.048376 5.41E-05 -1.01E-03 -7.20E-03 51.71969 50.042 0.098799 1.11E-04 -1.26E-03 -8.99E-03 51.72788 50.003 0.498204 5.59E-04 1.32E-03 9.49E-03 51.73951 50.008 0.999556 1.13E-03 0.005 0.04 51.76643 50.028 2.497429 2.84E-03 0.013 0.10 51.81263 50.047 3.99956 4.58E-03 0.027 0.20 51.84383 50.018 5.496608 6.36E-03 0.036 0.27 51.87481 50.018 6.999152 8.18E-03 0.045 0.34 51.91181 50.003 8.488919 1.00E-02 0.055 0.42 51.94167 50.023 9.996134 1.19E-02 0.064 0.49 51.97133 50.003 10.99197 1.32E-02 0.072 0.55 52.00324 50.033 12.00978 1.45E-02 0.080 0.62 52.01247 50.028 12.99861 1.58E-02 0.083 0.65 52.01247 50.028 12.99861 1.58E-02 0.083 0.65 51.98586 50.023 11.00392 1.32E-02 0.075 0.58 51.88923 50.033 5.998922 6.96E-03 0.048 0.36 51.78248 49.989 1.999649 2.26E-03 0.017 0.12 51.73993 50.037 0.19841 2.22E-04 0.004 0.03 51.73011 50.028 0.072969 8.17E-05 1.53E-03 1.10E-02 51.72524 50.003 0.020485 2.29E-05 1.70E-04 1.22E-03

206 TABLE D-15 ETHANE IN [bmim][PF6]

10 oC 90 min Sachem SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density (g / Fraction of (mg) (oC) (bar) cm3) Gas Wt % Gas 53.56979 15.755 0.0002 2.50E-07 1.15E-06 1.21E-05 53.56649 10.084 0.0074 9.43E-06 -5.41E-04 -5.70E-03 53.56545 10.079 0.0483 6.16E-05 -4.85E-04 -5.11E-03 53.55946 10.084 0.1973 2.52E-04 -6.70E-04 -7.06E-03 53.55286 10.093 0.5983 7.66E-04 5.29E-04 5.59E-03 53.54625 10.088 0.9995 1.28E-03 1.74E-03 1.84E-02 53.52705 10.093 1.9997 2.59E-03 0.004 0.05 53.51135 10.075 2.9994 3.93E-03 0.008 0.08 53.49773 10.091 3.9997 5.29E-03 0.011 0.12 53.48348 10.079 4.9973 6.68E-03 0.015 0.16 53.46738 10.079 5.9989 8.10E-03 0.019 0.20 53.45147 10.084 6.9985 9.55E-03 0.022 0.24 53.43475 10.088 7.9996 1.10E-02 0.026 0.28 53.4174 10.084 8.9987 1.25E-02 0.030 0.32 53.39841 10.082 9.9986 1.41E-02 0.033 0.36 53.37713 10.093 10.9993 1.57E-02 0.037 0.40 53.35236 10.084 11.9993 1.73E-02 0.040 0.43 53.32882 10.082 12.9999 1.90E-02 0.043 0.47 53.32882 10.084 13.0006 1.90E-02 0.043 0.47 53.35174 10.082 12.5001 1.82E-02 0.043 0.47 53.38952 10.079 11.4998 1.65E-02 0.042 0.46 53.41906 10.084 10.4997 1.49E-02 0.040 0.44 53.44527 10.077 9.5 1.33E-02 0.038 0.41 53.4682 10.079 8.4985 1.18E-02 0.035 0.38 53.48719 10.079 7.4984 1.03E-02 0.032 0.34 53.50784 10.084 6.4989 8.82E-03 0.029 0.31 53.52457 10.079 5.499 7.39E-03 0.025 0.27 53.53923 10.091 4.4991 5.98E-03 0.022 0.23 53.55431 10.079 3.4991 4.61E-03 0.018 0.19 53.56649 10.088 2.4995 3.26E-03 0.014 0.15 53.57702 10.079 1.4997 1.94E-03 0.010 0.11 53.58673 10.075 0.499 6.39E-04 0.006 0.06 53.58673 10.073 0.0955 1.22E-04 0.004 0.04

207 TABLE D-15 SOLUBILITY OF ETHANE IN [bmim][PF6] (cont.)

25 oC 90 min Sachem SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 53.58962 25.088 0 0 0 0 53.58693 25.075 0.0097 1.17E-05 -4.21E-04 -4.44E-03 53.58569 25.077 0.0479 5.80E-05 -4.25E-04 -4.48E-03 53.57826 25.075 0.1968 2.38E-04 -8.98E-04 -9.47E-03 53.56772 25.073 0.5983 7.27E-04 -4.83E-04 -5.10E-03 53.56132 25.075 0.9992 1.22E-03 6.73E-04 7.11E-03 53.54233 25.073 1.9977 2.46E-03 0.003 0.03 53.52663 25.073 2.9969 3.71E-03 0.006 0.07 53.51135 25.068 3.9985 4.99E-03 0.009 0.10 53.49422 25.068 4.9993 6.30E-03 0.012 0.13 53.47625 25.073 5.9979 7.62E-03 0.015 0.16 53.45849 25.073 6.9978 8.97E-03 0.018 0.20 53.44363 25.081 7.9988 1.03E-02 0.022 0.24 53.42009 25.084 8.9994 1.17E-02 0.024 0.26 53.39407 25.081 9.9998 1.32E-02 0.026 0.28 53.37094 25.068 10.9988 1.46E-02 0.029 0.31 53.35009 25.081 11.9991 1.61E-02 0.032 0.34 53.32676 25.073 12.9983 1.76E-02 0.034 0.37 53.32676 25.044 12.9972 1.76E-02 0.034 0.37 53.34327 25.077 12.4986 1.69E-02 0.034 0.37 53.37363 25.066 11.4988 1.54E-02 0.032 0.35 53.40027 25.073 10.4975 1.39E-02 0.030 0.33 53.42402 25.077 9.4996 1.24E-02 0.028 0.30 53.44342 25.073 8.4985 1.10E-02 0.025 0.27 53.4651 25.075 7.499 9.65E-03 0.022 0.24 53.48307 25.081 6.4991 8.29E-03 0.019 0.21 53.50082 25.07 5.4991 6.95E-03 0.016 0.18 53.51879 25.066 4.4995 5.64E-03 0.014 0.15 53.53407 25.075 3.4989 4.35E-03 0.010 0.11 53.54852 25.077 2.4993 3.08E-03 0.007 0.07 53.56339 25.079 1.4992 1.84E-03 0.004 0.04 53.57309 25.079 0.4985 6.05E-04 0.000 0.00 53.5733 25.068 0.0952 1.15E-04 -0.002 -0.02 53.5733 25.528 0.0032 3.8661E-06 -0.00288 -0.03027

208 TABLE D-15 SOLUBILITY OF ETHANE IN [bmim][PF6] (cont.)

25 oC 90 min Sachem SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction Wt % (mg) (oC) (bar) (g / cm3) of Gas Gas 82.84484 25.954 0.0003 3.62E-07 1.98E-06 2.09E-05 82.84525 25.09 0.0162 1.96E-05 1.54E-04 1.63E-03 82.84525 25.079 0.0528 6.39E-05 3.96E-04 4.18E-03 82.84277 25.066 0.2027 2.46E-04 1.11E-03 1.17E-02 82.82874 25.07 0.598 7.27E-04 2.13E-03 2.25E-02 82.81407 25.07 0.9993 1.22E-03 3.13E-03 3.32E-02 82.77587 25.075 2.0047 2.46E-03 0.006 0.06 82.74532 25.077 2.9989 3.72E-03 0.009 0.09 82.71289 25.075 4.0049 5.00E-03 0.012 0.13 82.68006 25.073 5.0037 6.30E-03 0.015 0.16 82.64455 25.081 6.0055 7.63E-03 0.018 0.20 82.60799 25.073 7.0048 8.97E-03 0.022 0.23 82.5696 25.086 8.0048 1.03E-02 0.024 0.26 82.53243 25.079 9.0039 1.17E-02 0.028 0.30

50 oC 90 min Sachem SS bucket

Mass Sample Sample Mole Reading Temperature Pressure Gas Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 53.56566 50.017 0 0.00E+00 0.00E+00 0.00E+00 53.56339 50.017 0.0067 7.48E-06 -3.66E-04 -3.86E-03 53.56277 50.019 0.0472 5.27E-05 -2.60E-04 -2.75E-03 53.56091 50.019 0.1952 2.18E-04 1.99E-04 2.10E-03 53.55038 50.017 0.5976 6.70E-04 4.86E-04 5.13E-03 53.54377 50.035 0.9989 1.12E-03 1.47E-03 1.55E-02 53.5223 50.019 1.9976 2.26E-03 0.003 0.03 53.51032 50.015 2.9987 3.41E-03 0.006 0.07 53.50062 50.002 3.9967 4.57E-03 0.010 0.11 53.48864 50.008 4.9968 5.75E-03 0.014 0.15 53.47109 50.004 5.998 6.95E-03 0.016 0.17 53.45416 50.015 6.9964 8.16E-03 0.019 0.20 53.43124 50.022 7.9988 9.39E-03 0.021 0.22 53.41719 50.031 8.9988 1.06E-02 0.024 0.26 53.38705 50.024 9.9989 1.19E-02 0.024 0.26

209 TABLE D-16 ETHANE IN [bmim][NO3]

10 oC 120 min JFB SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 73.76756 12.773 0 0.00E+00 0.00E+00 0.00E+00 73.76605 10.079 0.0126 1.61E-05 -6.42E-05 -9.57E-04 73.76479 10.079 0.0503 6.41E-05 4.01E-05 5.98E-04 73.75905 10.073 0.1986 2.53E-04 3.80E-04 5.67E-03 73.74178 10.082 0.6004 7.69E-04 1.16E-03 1.73E-02 73.72726 10.082 1.001 1.29E-03 0.002 0.03 73.68674 10.079 2.0008 2.60E-03 0.004 0.07 73.64619 10.082 3.0007 3.93E-03 0.007 0.10 73.60416 10.079 4.0012 5.29E-03 0.009 0.14 73.56186 10.079 5.0021 6.68E-03 0.012 0.17 73.52007 10.079 6.0013 8.10E-03 0.014 0.21 73.47553 10.093 7.0018 9.55E-03 0.017 0.25 73.43048 10.088 8.0017 1.10E-02 0.019 0.29 73.3827 10.079 9.0013 1.26E-02 0.022 0.33 73.3344 10.084 10.0006 1.41E-02 0.024 0.37 73.28185 10.079 11.0018 1.57E-02 0.027 0.41 73.22804 10.077 12.0008 1.73E-02 0.029 0.44 73.17174 10.079 13.0014 1.90E-02 0.031 0.48 73.17198 10.073 13.0028 1.90E-02 0.031 0.48 73.21853 10.082 12.501 1.82E-02 0.032 0.49 73.2901 10.086 11.5013 1.65E-02 0.031 0.47

210 TABLE D-16 ETHANE IN [bmim][NO3] (cont.)

25 oC 120 min JFB SS bucket

Mass Sample Sample Gas Density Mole Wt % Gas Reading Temperature Pressure (g / cm3) Fraction of (mg) (oC) (bar) Gas 73.74704 24.911 0 0.00E+00 0.00E+00 0.00E+00 73.74729 25.086 0.0093 1.13E-05 7.45E-05 1.11E-03 73.74479 25.075 0.048 5.81E-05 6.29E-05 9.38E-04 73.73902 25.077 0.199 2.41E-04 3.81E-04 5.68E-03 73.72302 25.073 0.5997 7.29E-04 1.17E-03 1.75E-02 73.7085 25.081 1.0015 1.22E-03 0.002 0.03 73.66921 25.075 2 2.46E-03 0.004 0.06 73.63093 25.075 3.0017 3.72E-03 0.007 0.10 73.59114 25.075 4.0017 5.00E-03 0.009 0.13 73.5496 25.075 5.0017 6.30E-03 0.011 0.16 73.51056 25.073 6.0009 7.62E-03 0.013 0.20 73.46352 25.079 7.0014 8.97E-03 0.015 0.23 73.41898 25.075 8.001 1.03E-02 0.017 0.26 73.36968 25.075 9.0021 1.17E-02 0.019 0.29 73.32163 25.073 10.0011 1.32E-02 0.021 0.33 73.27158 25.073 11.0022 1.46E-02 0.024 0.36 73.21853 25.079 12.0008 1.61E-02 0.025 0.39 73.16573 25.07 13.0016 1.76E-02 0.027 0.42 73.16573 25.073 13.0002 1.76E-02 0.027 0.42 73.20126 25.077 12.5016 1.69E-02 0.027 0.42 73.26458 25.077 11.5006 1.54E-02 0.026 0.40

211 TABLE D-16 ETHANE IN [bmim][NO3] (cont.)

50 oC 120 min JFB SS bucket

Mass Sample Sample Gas Mole Wt % Gas Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas 73.73653 50.059 0 0.00E+00 0.00E+00 0.00E+00 73.73203 50.019 0.0129 1.44E-05 -3.42E-04 -5.10E-03 73.73102 50.019 0.0504 5.63E-05 -2.37E-04 -3.53E-03 73.72601 50.015 0.198 2.21E-04 8.20E-05 1.22E-03 73.71075 50.017 0.6005 6.73E-04 8.13E-04 1.21E-02 73.69849 50.017 1.0005 1.12E-03 0.002 0.03 73.66296 50.008 2.0006 2.26E-03 0.004 0.06 73.61916 50.033 3.0012 3.41E-03 0.005 0.08 73.59114 50.046 4.0005 4.58E-03 0.008 0.12 73.5471 50.019 5.0021 5.76E-03 0.010 0.15 73.50105 50.037 6.0018 6.95E-03 0.011 0.17 73.48378 49.969 7.0006 8.16E-03 0.015 0.23 73.42373 50.006 8.0017 9.39E-03 0.015 0.23 73.40746 50.024 8.9998 1.06E-02 0.020 0.30 73.33489 50.05 9.9995 1.19E-02 0.019 0.29 73.28159 49.995 11.0016 1.32E-02 0.020 0.30 73.22078 50.07 12.002 1.45E-02 0.021 0.31 73.2288 50.052 13.002 1.58E-02 0.027 0.41 73.25957 50.043 13.002 1.58E-02 0.030 0.46 73.22229 49.984 12.5019 1.51E-02 0.024 0.36 73.27258 50.026 11.5013 1.38E-02 0.022 0.34 73.32563 50.006 10.5007 1.25E-02 0.021 0.32 73.33464 50.013 9.5019 1.13E-02 0.016 0.24 73.41898 50.028 8.5021 1.00E-02 0.018 0.27 73.44725 50.037 7.5017 8.78E-03 0.015 0.22 73.50806 50.031 6.5021 7.56E-03 0.014 0.22 73.54485 49.995 5.5012 6.35E-03 0.012 0.18 73.57938 50.008 4.5007 5.17E-03 0.010 0.15 73.62042 50.013 3.5014 3.99E-03 0.008 0.12 73.65695 49.982 2.5013 2.84E-03 0.006 0.09 73.69874 50.022 1.5012 1.69E-03 0.004 0.07 73.72977 50.019 0.501 5.61E-04 0.002 0.03 73.74178 50.022 0.0975 1.09E-04 9.88E-04 1.47E-02 73.74328 50.226 0.0031 3.46E-06 6.30E-04 9.40E-03

212 TABLE D-17 ETHYLENE IN [bmim][Tf2N]

10 oC 90 min Covalent Q1 bucket

Mass Sample Sample Reading Temperature Pressure Gas Density Mole Fraction (mg) (oC) (bar) (g / cm3) of Gas Wt % Gas 51.71518 11.228 0.021584 2.56E-05 1.58E-05 1.05E-04 51.71296 10.302 0.047414 5.64E-05 -6.09E-04 -4.06E-03 51.7131 10.144 0.099486 1.18E-04 -5.30E-04 -3.53E-03 51.73041 10.038 0.500265 5.97E-04 0.005 0.03 51.75642 9.914 0.998869 1.20E-03 0.013 0.08 51.83321 9.899 2.49839 3.02E-03 0.035 0.24 51.91791 9.866 3.998873 4.89E-03 0.058 0.41 52.00368 9.837 5.499906 6.80E-03 0.081 0.58 52.09007 10.034 6.998603 8.75E-03 0.102 0.76 52.17185 10.072 8.4973 1.07E-02 0.122 0.92 52.25488 10.11 10.00094 1.28E-02 0.141 1.08 52.314 9.918 11.00145 1.42E-02 0.154 1.20 52.36723 9.861 12.00401 1.56E-02 0.166 1.31 52.4184 9.875 12.99202 1.71E-02 0.176 1.41 52.4184 9.875 12.99202 1.71E-02 0.176 1.41 52.32972 10.105 10.99925 1.42E-02 0.157 1.23 52.08451 10.153 6.003044 7.44E-03 0.100 0.74 51.86218 9.966 1.999512 2.41E-03 0.042 0.29 51.74908 10.072 0.19841 2.36E-04 0.010 0.07 51.72913 10.034 0.073244 8.71E-05 0.004 0.03 51.71907 10.029 0.021446 2.55E-05 1.14E-03 7.63E-03

213 TABLE D-17 ETHYLENE IN [bmim][Tf2N] (cont.)

25 oC 90 min Covalent Q1 bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density (g / Fraction of (mg) (oC) (bar) cm3) Gas Wt % Gas 51.71252 31.67 0.0007 7.73E-07 5.53E-07 3.69E-06 51.70943 24.961 0.019111 2.16E-05 -8.80E-04 -5.87E-03 51.7112 25.043 0.046864 5.29E-05 -3.45E-04 -2.30E-03 51.71374 25.019 0.098937 1.12E-04 0.000 0.00 51.73212 25.043 0.498754 5.65E-04 0.006 0.04 51.7552 25.019 0.999007 1.13E-03 0.013 0.09 51.82254 25.019 2.499352 2.86E-03 0.033 0.23 51.89035 25.019 3.998324 4.62E-03 0.052 0.36 51.95792 24.999 5.497158 6.41E-03 0.070 0.50 52.02568 25.028 6.999427 8.24E-03 0.088 0.64 52.0906 25.033 8.497024 1.01E-02 0.105 0.77 52.15232 24.97 10.00452 1.20E-02 0.120 0.90 52.19867 24.97 10.99815 1.33E-02 0.131 0.99 52.24067 24.956 11.99879 1.46E-02 0.140 1.08 52.28018 24.99 13.00053 1.59E-02 0.150 1.16 52.28018 24.99 13.00053 1.59E-02 0.150 1.16 52.20604 25.052 10.99843 1.33E-02 0.132 1.01 52.00772 25.009 6.002495 7.03E-03 0.083 0.60 51.8315 24.98 1.999237 2.28E-03 0.035 0.24 51.74078 24.995 0.19841 2.24E-04 0.008 0.06 51.72571 25.004 0.073381 8.29E-05 3.86E-03 2.59E-02 51.71785 25.009 0.023507 2.84E-05 1.56E-03 1.04E-02

214 TABLE D-17 ETHYLENE IN [bmim][Tf2N] (cont.)

50 oC 90 min Covalent Q1 bucket

Mass Sample Sample Gas Reading Temperature Pressure Density Mole Fraction (mg) (oC) (bar) (g / cm3) of Gas Wt % Gas 51.71611 46.214 0.021584 2.28E-05 2.01E-05 1.34E-04 51.71183 50.067 0.048101 5.01E-05 -1.20E-03 -7.98E-03 51.71112 50.042 0.099074 1.03E-04 -1.36E-03 -9.04E-03 51.72363 50.008 0.500403 5.23E-04 0.003 0.02 51.73922 50.018 0.999007 1.05E-03 0.008 0.05 51.7747 50.013 2.49839 2.63E-03 0.019 0.13 51.83482 50.023 3.997499 4.24E-03 0.037 0.25 51.89013 50.028 5.492624 5.87E-03 0.053 0.37 51.93271 50.013 6.998877 7.53E-03 0.065 0.46 51.97779 50.028 8.499498 9.21E-03 0.077 0.56 52.03243 50.052 9.998607 1.09E-02 0.092 0.67 52.06927 49.936 10.99884 1.21E-02 0.101 0.75 52.07426 49.965 11.9922 1.32E-02 0.103 0.76 52.11544 50.013 13.00644 1.44E-02 0.114 0.85 52.11544 50.013 13.00644 1.44E-02 0.114 0.85 52.06736 49.984 10.99581 1.21E-02 0.101 0.74 51.93225 49.974 5.997548 6.42E-03 0.064 0.45 51.79645 49.989 2.004595 2.11E-03 0.025 0.17 51.73393 50.042 0.198273 2.07E-04 0.005 0.04 51.72231 50.023 0.073107 7.62E-05 1.86E-03 1.24E-02 51.71545 49.989 0.021996 2.29E-05 -1.71E-04 -1.14E-03

215 TABLE D-18 ETHYLENE IN [bmim][PF6]

10 oC 120 min Sachem SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction Wt % (mg) (oC) (bar) (g / cm3) of Gas Gas 82.86218 16.566 0 0.00E+00 0 0 82.86176 10.084 0.0148 1.76E-05 6.21E-05 6.12E-04 82.86135 10.082 0.053 6.30E-05 3.05E-04 3.00E-03 82.85908 10.077 0.2018 2.40E-04 1.17E-03 1.15E-02 82.85372 10.091 0.5978 7.14E-04 0.004 0.04 82.85268 10.086 0.9979 1.19E-03 0.006 0.06 82.8562 10.082 2.0043 2.42E-03 0.015 0.15 82.86301 10.079 2.9981 3.64E-03 0.023 0.23 82.86796 10.079 4.0035 4.89E-03 0.031 0.32 82.87189 10.079 5.0043 6.16E-03 0.039 0.40 82.87685 10.079 6.0047 7.45E-03 0.047 0.49 82.8783 10.084 7.0045 8.75E-03 0.055 0.57 82.8787 10.084 8.0042 1.01E-02 0.063 0.66 82.8785 10.079 9.0045 1.14E-02 0.070 0.74 82.87685 10.084 10.0042 1.28E-02 0.078 0.82 82.87272 10.091 11.0049 1.42E-02 0.085 0.91 82.86569 10.084 12.0034 1.56E-02 0.092 0.99 82.85764 10.082 13.0037 1.71E-02 0.099 1.07 82.85764 10.093 13.0036 1.70E-02 0.099 1.07 82.88181 10.082 12.4985 1.63E-02 0.097 1.05 82.89832 10.079 11.498 1.49E-02 0.091 0.98

216 TABLE D-18 ETHYLENE IN [bmim][PF6] (cont.)

25 oC 120 min Sachem SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction Wt % (mg) (oC) (bar) (g / cm3) of Gas Gas 82.86157 25.084 0 0.00E+00 0.00E+00 0.00E+00 82.8624 25.081 0.0152 1.72E-05 2.12E-04 2.09E-03 82.8624 25.081 0.0516 5.83E-05 4.76E-04 4.69E-03 82.86218 25.073 0.2002 2.26E-04 1.53E-03 1.51E-02 82.85641 25.073 0.5969 6.76E-04 0.004 0.04 82.85455 25.068 0.9979 1.13E-03 0.006 0.06 82.84856 25.068 2.0026 2.29E-03 0.013 0.13 82.85103 25.068 2.9958 3.44E-03 0.020 0.20 82.84608 25.073 4.0044 4.63E-03 0.027 0.27 82.83885 25.073 5.0044 5.82E-03 0.033 0.34 82.8308 25.075 6.0037 7.03E-03 0.040 0.41 82.82439 25.077 7.0029 8.25E-03 0.046 0.48 82.81594 25.073 8.0035 9.48E-03 0.052 0.54 82.80478 25.07 9.005 1.07E-02 0.058 0.61 82.7928 25.07 10.0032 1.20E-02 0.064 0.67 82.77814 25.077 11.004 1.33E-02 0.070 0.74 82.76306 25.07 12.0041 1.46E-02 0.076 0.80 82.7478 25.081 13.0036 1.59E-02 0.081 0.86

217 TABLE D-18 ETHYLENE IN [bmim][PF6] (cont.)

25 oC 90 min Sachem SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 82.88738 24.898 0 0.00E+00 0.00E+00 0.00E+00 82.8783 25.084 0.0095 1.07E-05 -1.04E-03 -1.03E-02 82.87766 25.07 0.0477 5.39E-05 -8.44E-04 -8.31E-03 82.87623 25.075 0.1952 2.21E-04 5.40E-05 5.32E-04 82.86569 25.077 0.597 6.76E-04 1.69E-03 1.67E-02 82.8626 25.07 0.9971 1.13E-03 0.004 0.04 82.85557 25.075 1.9973 2.28E-03 0.011 0.11 82.8531 25.068 2.9969 3.44E-03 0.018 0.18 82.84876 25.081 3.9981 4.62E-03 0.024 0.25 82.84277 25.077 4.9985 5.81E-03 0.031 0.31 82.83617 25.068 5.9987 7.02E-03 0.037 0.38 82.82956 25.068 6.9987 8.24E-03 0.044 0.45 82.82068 25.081 7.9986 9.48E-03 0.050 0.52 82.80953 25.077 8.9984 1.07E-02 0.056 0.58 82.80023 25.079 9.9983 1.20E-02 0.062 0.65 82.78827 25.084 10.9989 1.33E-02 0.068 0.72 82.77422 25.077 11.998 1.46E-02 0.074 0.78 82.75852 25.077 12.9986 1.59E-02 0.080 0.85 82.75852 25.051 12.9983 1.59E-02 0.080 0.85 82.78227 25.075 12.4979 1.53E-02 0.079 0.83 82.80994 25.081 11.4982 1.39E-02 0.074 0.78 82.82501 25.079 10.4984 1.26E-02 0.069 0.72 82.83988 25.077 9.4978 1.14E-02 0.063 0.66 82.85226 25.073 8.4987 1.01E-02 0.057 0.59 82.86342 25.07 7.4984 8.86E-03 0.051 0.53 82.87251 25.07 6.4984 7.63E-03 0.045 0.46 82.88035 25.073 5.4972 6.41E-03 0.039 0.40 82.88738 25.079 4.4982 5.22E-03 0.032 0.33 82.89275 25.079 3.4987 4.03E-03 0.026 0.26 82.89668 25.077 2.4985 2.86E-03 0.019 0.19 82.9008 25.073 1.4981 1.71E-03 0.012 0.12 82.90162 25.073 0.4977 5.64E-04 0.005 0.05 82.89501 25.077 0.0956 1.08E-04 1.63E-03 1.60E-02

218 TABLE D-18 ETHYLENE IN [bmim][PF6] (cont.)

50 oC 120 min Sachem SS bucket

Mass Sample Sample Gas Reading Temperature Pressure Density Mole Fraction (mg) (oC) (bar) (g / cm3) of Gas Wt % Gas 82.88449 50.024 0 0.00E+00 0.00E+00 0.00E+00 82.88159 50.013 0.0064 6.67E-06 -3.13E-04 -3.09E-03 82.88055 50.019 0.0471 4.91E-05 -1.75E-04 -1.73E-03 82.87623 50.015 0.1953 2.04E-04 2.63E-04 2.59E-03 82.86487 50.019 0.5948 6.21E-04 1.48E-03 1.46E-02 82.85867 50.015 0.9982 1.04E-03 0.003 0.03 82.84443 50.019 1.9988 2.10E-03 0.008 0.08 82.84835 50.017 2.9988 3.17E-03 0.015 0.15 82.83225 50.015 3.9986 4.24E-03 0.020 0.20 82.81572 50.013 4.9988 5.33E-03 0.024 0.24 82.81428 50.01 5.9978 6.42E-03 0.031 0.31 82.79611 50.022 6.9987 7.53E-03 0.035 0.36 82.78351 50.022 7.998 8.64E-03 0.040 0.41 82.76101 50.017 8.9975 9.77E-03 0.044 0.45 82.73912 50.017 9.9986 1.09E-02 0.048 0.49 82.71393 50.035 10.9989 1.21E-02 0.052 0.53 82.7005 50.022 11.9974 1.32E-02 0.057 0.59 82.6813 50.019 12.997 1.44E-02 0.061 0.64 82.6813 49.984 12.9966 1.44E-02 0.061 0.64 82.68398 50.037 12.499 1.38E-02 0.058 0.61 82.69947 50.024 11.4977 1.26E-02 0.053 0.55 82.72735 50.013 10.4981 1.15E-02 0.050 0.52 82.74654 50.019 9.4984 1.03E-02 0.046 0.47 82.77133 50.013 8.4977 9.21E-03 0.042 0.43 82.7928 50.008 7.4986 8.08E-03 0.038 0.39 82.80705 50.017 6.4983 6.97E-03 0.033 0.34 82.81531 50.015 5.4987 5.87E-03 0.028 0.28 82.82874 50.031 4.4974 4.78E-03 0.023 0.23 82.84794 50.013 3.498 3.70E-03 0.018 0.18 82.85124 50.006 2.4972 2.63E-03 0.012 0.12 82.87065 50.017 1.4987 1.57E-03 0.008 0.08 82.88119 50.017 0.4984 5.21E-04 0.003 0.03 82.88304 50.019 0.0946 9.86E-05 0.000 0.00 82.88304 50.037 0.0024 2.50E-06 -1.62E-04 -1.60E-03

219 TABLE D-19 ETHYLENE IN [bmim][NO3]

10 oC 120 min JFB SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density (g Fraction Wt % (mg) (oC) (bar) / cm3) of Gas Gas 73.84613 11.639 0 0.00E+00 0.00E+00 0.00E+00 73.84663 10.091 0.0128 1.52E-05 1.23E-04 1.71E-03 73.84613 10.091 0.0499 5.94E-05 2.90E-04 4.03E-03 73.84438 10.079 0.1988 2.37E-04 9.84E-04 1.37E-02 73.83762 10.086 0.5995 7.16E-04 0.003 0.04 73.83362 10.082 1.0014 1.20E-03 0.005 0.06 73.81885 10.079 2.0014 2.41E-03 0.009 0.13 73.80759 10.079 3.0008 3.64E-03 0.014 0.19 73.79507 10.079 4.0014 4.89E-03 0.019 0.26 73.78382 10.086 5.0008 6.16E-03 0.023 0.33 73.77081 10.086 6.0015 7.44E-03 0.028 0.40 73.75805 10.082 7.0015 8.75E-03 0.033 0.47 73.74353 10.079 8.0013 1.01E-02 0.038 0.54 73.72877 10.086 9.0006 1.14E-02 0.042 0.61 73.7105 10.082 10.0004 1.28E-02 0.047 0.68 73.68748 10.088 11.0024 1.42E-02 0.051 0.74 73.66621 10.079 12.0017 1.56E-02 0.055 0.81 73.64545 10.084 13.0008 1.70E-02 0.060 0.88 73.64494 10.095 12.9998 1.70E-02 0.060 0.88 73.67472 10.077 12.5008 1.63E-02 0.059 0.87 73.71551 10.079 11.5014 1.49E-02 0.057 0.83 73.74929 10.079 10.5008 1.35E-02 0.053 0.78 73.76781 10.082 9.5019 1.21E-02 0.049 0.71 73.79133 10.075 8.5017 1.07E-02 0.045 0.65 73.8101 10.082 7.5018 9.41E-03 0.041 0.59 73.82686 10.079 6.5022 8.10E-03 0.036 0.52 73.84113 10.082 5.5021 6.80E-03 0.032 0.45 73.85564 10.084 4.5017 5.52E-03 0.027 0.39 73.86715 10.079 3.5019 4.27E-03 0.022 0.32 73.87566 10.075 2.5011 3.03E-03 0.017 0.24 73.88242 10.079 1.5012 1.80E-03 0.012 0.17 73.87341 10.071 0.501 5.98E-04 0.006 0.08 73.86565 10.084 0.0974 1.16E-04 0.002 0.03 73.81285 14.141 0.0027 3.17E-06 -0.003 -0.04

220 TABLE D-19 ETHYLENE IN [bmim][NO3] (cont.)

25 oC 120 min JFB SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density (g Fraction of (mg) (oC) (bar) / cm3) Gas Wt % Gas 73.86765 26.076 0 0.00E+00 0.00E+00 0.00E+00 73.86315 25.075 0.0129 1.46E-05 -3.66E-04 -5.09E-03 73.86264 25.084 0.0501 5.66E-05 -2.08E-04 -2.90E-03 73.86089 25.07 0.1984 2.24E-04 4.49E-04 6.26E-03 73.85464 25.075 0.6002 6.80E-04 0.002 0.03 73.84913 25.075 1.0003 1.14E-03 0.004 0.05 73.83337 25.073 1.9996 2.28E-03 0.008 0.11 73.8176 25.07 3.0007 3.45E-03 0.012 0.17 73.79934 25.073 4.0017 4.63E-03 0.016 0.22 73.78257 25.079 5.0009 5.82E-03 0.020 0.28 73.76279 25.079 6.0018 7.02E-03 0.024 0.34 73.74353 25.077 7.0017 8.24E-03 0.028 0.40 73.72302 25.079 8.0017 9.48E-03 0.032 0.45 73.69899 25.07 9.0007 1.07E-02 0.035 0.51 73.67496 25.077 10.0008 1.20E-02 0.039 0.56 73.65295 25.075 11.0009 1.33E-02 0.043 0.62 73.62441 25.073 12.0012 1.46E-02 0.046 0.67 73.59639 25.073 13.0012 1.59E-02 0.050 0.72 73.59589 25.064 13.0002 1.59E-02 0.050 0.72 73.61967 25.077 12.5018 1.53E-02 0.049 0.71 73.65295 25.075 11.5001 1.39E-02 0.046 0.66 73.68198 25.079 10.5019 1.26E-02 0.042 0.61 73.71 25.081 9.5018 1.14E-02 0.039 0.56 73.73554 25.075 8.5014 1.01E-02 0.036 0.51 73.76005 25.073 7.5019 8.86E-03 0.032 0.46 73.78082 25.075 6.5009 7.63E-03 0.028 0.40 73.80259 25.077 5.5018 6.42E-03 0.025 0.35 73.82186 25.075 4.5013 5.22E-03 0.021 0.30 73.84062 25.077 3.5011 4.04E-03 0.017 0.24 73.85513 25.077 2.5007 2.87E-03 0.013 0.18 73.8709 25.068 1.5013 1.71E-03 0.009 0.12 73.88117 25.073 0.5007 5.67E-04 0.004 0.06 73.88017 25.077 0.0974 1.10E-04 0.002 0.02

221 TABLE D-19 ETHYLENE IN [bmim][NO3] (cont.)

50 oC 120 min JFB SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 73.8176 50.019 0 0.00E+00 0.00E+00 0.00E+00 73.8176 50.01 0.0105 1.09E-05 5.50E-05 7.66E-04 73.81735 50.017 0.0506 5.27E-05 2.41E-04 3.35E-03 73.81485 50.015 0.1995 2.08E-04 7.78E-04 1.08E-02 73.80659 50.017 0.5996 6.27E-04 0.002 0.03 73.79883 50.022 1.0004 1.05E-03 0.003 0.05 73.78707 50.019 2.0012 2.10E-03 0.008 0.11 73.74778 50.028 3.0007 3.17E-03 0.009 0.13 73.74253 50.017 4.0012 4.24E-03 0.014 0.20 73.71025 50.01 5.0016 5.33E-03 0.016 0.23 73.70199 50.035 6.0008 6.42E-03 0.021 0.29 73.68597 49.982 6.9999 7.53E-03 0.024 0.35 73.66846 50.037 8.0017 8.65E-03 0.028 0.40 73.63543 49.982 9.0012 9.78E-03 0.030 0.44 73.58338 50.002 10.0012 1.09E-02 0.031 0.44 73.57262 49.984 11.0025 1.21E-02 0.036 0.51 73.52808 50.031 12.0019 1.32E-02 0.037 0.53 73.50656 50.046 13.0008 1.44E-02 0.040 0.58 73.5053 50.07 13.001 1.44E-02 0.040 0.58 73.52207 50.026 12.5014 1.38E-02 0.039 0.56 73.54509 50.028 11.5011 1.26E-02 0.036 0.51 73.6079 49.949 10.4994 1.15E-02 0.036 0.52 73.62216 50.037 9.5015 1.03E-02 0.032 0.46

222 TABLE D-20 METHANE IN [bmim][PF6]

10 oC 90 min Sachem SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction Wt % (mg) (oC) (bar) (g / cm3) of Gas Gas 76.67157 10.128 0.0001 6.79E-08 6.74E-07 3.79E-06 76.67053 10.086 0.0378 2.57E-05 1.37E-05 7.72E-05 76.66661 10.075 0.192 1.31E-04 1.45E-04 8.16E-04 76.6563 10.086 0.5884 4.00E-04 4.31E-04 2.43E-03 76.64578 10.064 0.9895 6.74E-04 7.05E-04 3.97E-03 76.6202 10.088 1.9887 1.36E-03 1.55E-03 8.73E-03 76.59442 10.064 2.9879 2.04E-03 2.38E-03 1.34E-02 76.56843 10.093 3.9893 2.73E-03 3.19E-03 1.80E-02 76.54141 10.042 4.9893 3.43E-03 3.80E-03 2.15E-02 76.51563 10.073 5.989 4.12E-03 4.71E-03 2.66E-02 76.48654 10.008 6.9887 4.82E-03 4.90E-03 2.77E-02 76.45953 10.079 7.9884 5.52E-03 5.57E-03 3.15E-02 76.43333 10.102 8.988 6.22E-03 6.47E-03 3.66E-02 76.40444 10.099 9.9885 6.93E-03 6.78E-03 3.84E-02 76.37495 10.108 10.9891 7.64E-03 6.99E-03 3.96E-02 76.3502 10.157 11.9891 8.35E-03 8.29E-03 4.71E-02 76.3205 10.064 12.9893 9.07E-03 8.54E-03 4.85E-02 76.28811 10.055 13.9891 9.79E-03 8.18E-03 4.64E-02 76.28811 10.05 13.9907 9.79E-03 8.19E-03 4.65E-02 76.30193 10.077 13.4886 9.43E-03 7.80E-03 4.43E-02 76.3339 10.077 12.4892 8.71E-03 8.09E-03 4.59E-02 76.36258 10.155 11.4887 8.00E-03 7.63E-03 4.33E-02 76.39661 9.993 10.4881 7.29E-03 8.49E-03 4.82E-02 76.41908 10.108 9.4869 6.58E-03 6.66E-03 3.77E-02 76.44838 10.059 8.4875 5.87E-03 6.47E-03 3.66E-02 76.47685 10.079 7.4884 5.17E-03 6.10E-03 3.45E-02 76.50366 10.097 6.4868 4.47E-03 5.37E-03 3.04E-02 76.53006 10.064 5.487 3.77E-03 4.59E-03 2.60E-02 76.55421 10.088 4.4892 3.08E-03 3.33E-03 1.88E-02 76.58019 10.066 3.4865 2.39E-03 2.48E-03 1.40E-02 76.60741 10.048 2.4862 1.70E-03 1.97E-03 1.11E-02 76.6332 10.122 1.4863 1.01E-03 1.15E-03 6.49E-03 76.6596 10.026 0.4865 3.31E-04 5.08E-04 2.86E-03 76.66909 10.073 0.0855 5.81E-05 1.54E-06 8.70E-06

223 TABLE D-20 METHANE IN [bmim][PF6] (cont.)

10 oC 90 min Sachem SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 76.66744 10.028 0 0.00E+00 0.00E+00 0.00E+00 76.6629 10.088 0.0488 3.32E-05 -7.24E-04 -4.07E-03 76.66125 10.088 0.0999 6.79E-05 -7.62E-04 -4.28E-03 76.65157 10.084 0.5026 3.42E-04 -2.88E-04 -1.62E-03 76.63939 10.077 1.0017 6.82E-04 2.63E-04 1.48E-03 76.62598 10.088 1.5015 1.02E-03 5.40E-04 3.04E-03 76.6134 10.079 2.0025 1.37E-03 1.03E-03 5.78E-03 76.6002 10.079 2.5021 1.71E-03 1.36E-03 7.69E-03 76.58761 10.091 3.0019 2.05E-03 1.85E-03 1.04E-02 76.56121 10.084 4.002 2.74E-03 2.57E-03 1.45E-02 76.53481 10.088 5.0026 3.43E-03 3.32E-03 1.87E-02

224 TABLE D-20 METHANE IN [bmim][PF6] (cont.)

25 oC 120 min Sachem SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 76.66559 27.344 0.0001 6.40E-08 6.42E-07 3.62E-06 76.66414 25.079 0.0106 6.84E-06 -2.67E-04 -1.51E-03 76.66332 25.075 0.0524 3.38E-05 -1.87E-04 -1.05E-03 76.66002 25.07 0.2048 1.32E-04 3.52E-05 1.98E-04 76.65094 25.068 0.6017 3.89E-04 5.03E-04 2.83E-03 76.64104 25.07 1.0029 6.48E-04 8.13E-04 4.58E-03 76.61588 25.075 2.0022 1.30E-03 1.48E-03 8.36E-03 76.59091 25.077 3.002 1.95E-03 2.22E-03 1.25E-02 76.56534 25.066 4.0024 2.60E-03 2.85E-03 1.61E-02 76.54079 25.075 5.0012 3.26E-03 3.72E-03 2.10E-02 76.51398 25.07 6.0016 3.91E-03 4.11E-03 2.32E-02 76.48571 25.079 7.0026 4.57E-03 4.18E-03 2.36E-02 76.46096 25.079 8.0032 5.24E-03 5.09E-03 2.88E-02 76.43353 25.079 9.003 5.90E-03 5.39E-03 3.05E-02 76.40486 25.075 10.0025 6.57E-03 5.44E-03 3.08E-02 76.38774 25.075 11.0018 7.24E-03 8.14E-03 4.62E-02 76.35866 25.075 12.0023 7.91E-03 8.15E-03 4.62E-02 76.32111 25.079 13.0031 8.59E-03 6.24E-03 3.53E-02 76.32091 25.07 13.0035 8.59E-03 6.20E-03 3.51E-02 76.3438 25.07 12.5014 8.25E-03 8.08E-03 4.58E-02 76.36752 25.07 11.5021 7.57E-03 6.85E-03 3.88E-02 76.39372 25.079 10.5006 6.90E-03 6.19E-03 3.50E-02 76.41682 25.081 9.5015 6.23E-03 4.86E-03 2.75E-02 76.44632 25.073 8.5006 5.57E-03 5.01E-03 2.83E-02 76.47313 25.073 7.5012 4.90E-03 4.57E-03 2.59E-02 76.49831 25.068 6.5005 4.24E-03 3.78E-03 2.13E-02 76.52387 25.075 5.5002 3.58E-03 3.09E-03 1.75E-02 76.54925 25.075 4.4999 2.93E-03 2.39E-03 1.35E-02 76.57503 25.077 3.4996 2.27E-03 1.80E-03 1.02E-02 76.6002 25.073 2.4997 1.62E-03 1.10E-03 6.17E-03 76.62598 25.07 1.4995 9.70E-04 5.52E-04 3.11E-03 76.65135 25.075 0.4996 3.23E-04 -6.35E-05 -3.58E-04 76.66084 25.079 0.099 6.39E-05 -4.60E-04 -2.59E-03

225 TABLE D-20 METHANE IN [bmim][PF6] (cont.)

50 oC 90 min Sachem SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 76.66703 49.969 0 0.00E+00 0.00E+00 0.00E+00 76.66579 50.017 0.0136 8.10E-06 -2.05E-04 -1.15E-03 76.66496 50.019 0.052 3.10E-05 -1.63E-04 -9.18E-04 76.66146 50.017 0.2054 1.22E-04 -3.99E-05 -2.24E-04 76.65238 50.019 0.6014 3.58E-04 2.69E-04 1.52E-03 76.64289 50.024 1.0024 5.98E-04 5.17E-04 2.91E-03 76.61917 50.019 2.002 1.20E-03 1.13E-03 6.36E-03 76.60102 50.015 3.0017 1.79E-03 3.04E-03 1.72E-02 76.57977 50.026 4.0022 2.40E-03 4.25E-03 2.41E-02 76.55316 49.949 5.0015 3.00E-03 4.25E-03 2.40E-02 76.5276 50.002 6.0022 3.60E-03 4.50E-03 2.55E-02 76.50077 50.01 7.0025 4.21E-03 4.48E-03 2.53E-02 76.49335 50 8.0018 4.82E-03 8.91E-03 5.06E-02 76.45519 50.015 9.0028 5.43E-03 6.33E-03 3.59E-02 76.44488 50.031 10.0027 6.04E-03 1.01E-02 5.75E-02 76.41806 50 11.0013 6.65E-03 1.02E-02 5.77E-02 76.38031 50.068 12.0028 7.26E-03 7.72E-03 4.38E-02 76.36195 49.989 13.0022 7.88E-03 9.73E-03 5.53E-02 76.36258 50.052 13.0008 7.87E-03 9.85E-03 5.60E-02 76.383 50.037 12.5013 7.57E-03 1.14E-02 6.49E-02 76.39825 50.015 11.5004 6.95E-03 8.72E-03 4.95E-02 76.42445 50.002 10.5002 6.34E-03 8.53E-03 4.84E-02 76.44673 50.026 9.5022 5.73E-03 7.47E-03 4.23E-02 76.47417 50.019 8.5002 5.12E-03 7.58E-03 4.30E-02 76.50098 50.019 7.5013 4.51E-03 7.58E-03 4.30E-02 76.52078 49.995 6.4999 3.90E-03 5.99E-03 3.39E-02 76.52883 50.004 5.5003 3.30E-03 1.70E-03 9.61E-03 76.55997 50.019 4.5016 2.70E-03 2.75E-03 1.55E-02 76.57234 50.024 3.5 2.09E-03 -5.36E-04 -3.01E-03 76.60866 50.019 2.4998 1.49E-03 1.74E-03 9.81E-03 76.62969 50.019 1.4991 8.94E-04 4.92E-04 2.77E-03 76.65444 50.019 0.4993 2.98E-04 1.24E-04 7.00E-04 76.66351 50.013 0.0986 5.87E-05 -2.15E-04 -1.21E-03

226 TABLE D-20 METHANE IN [bmim][PF6] (cont.)

50 oC 90 min Sachem SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 76.66351 49.967 0.0001 5.96E-08 6.09E-07 3.43E-06 76.66125 50.019 0.0517 3.08E-05 -2.09E-04 -1.18E-03 76.65981 50.035 0.1002 5.97E-05 -2.47E-04 -1.39E-03 76.65032 50.019 0.5029 3.00E-04 7.11E-06 4.00E-05 76.63857 50.015 1.0022 5.98E-04 3.30E-04 1.86E-03 76.62619 50.017 1.5022 8.96E-04 5.15E-04 2.90E-03 76.61504 50.019 2.0026 1.20E-03 9.91E-04 5.58E-03 76.60618 50.013 2.5014 1.49E-03 1.99E-03 1.12E-02 76.59463 50.019 3.0018 1.79E-03 2.38E-03 1.34E-02 76.5808 50.015 4.0029 2.40E-03 5.30E-03 3.00E-02 76.54017 49.986 5.0017 3.00E-03 2.07E-03 1.17E-02

TABLE D-21 METHANE IN [bmim][BF4]

10 oC 90 min Welton Q4 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density (g Fraction Wt % (mg) (oC) (bar) / cm3) of Gas Gas 75.78426 15.755 0 0.00E+00 0.00E+00 0.00E+00 75.78446 10.079 0.0065 4.42E-06 7.80E-05 5.52E-04 75.78466 10.079 0.048 3.26E-05 3.75E-04 2.66E-03 75.78446 10.082 0.1958 1.33E-04 1.26E-03 8.96E-03 75.77539 10.082 0.5976 4.07E-04 2.09E-03 1.48E-02 75.76734 10.084 0.9974 6.79E-04 3.10E-03 2.20E-02 75.73106 10.079 1.999 1.36E-03 2.66E-03 1.89E-02 75.70322 10.084 2.9988 2.05E-03 3.80E-03 2.70E-02 75.67229 10.079 3.9985 2.74E-03 4.39E-03 3.12E-02 75.64115 10.084 4.9987 3.43E-03 4.97E-03 3.53E-02 75.61145 10.084 5.9985 4.13E-03 5.84E-03 4.15E-02 75.57723 10.079 6.9966 4.82E-03 5.89E-03 4.19E-02 75.54836 10.086 7.9982 5.53E-03 6.97E-03 4.97E-02 75.51598 10.084 8.999 6.23E-03 7.43E-03 5.30E-02 75.48567 10.077 9.9979 6.94E-03 8.29E-03 5.91E-02 75.45351 10.077 10.9974 7.65E-03 8.83E-03 6.30E-02 75.42298 10.088 11.9984 8.36E-03 9.71E-03 6.94E-02 75.39185 10.084 12.9988 9.08E-03 1.05E-02 7.51E-02

227 TABLE D-21 METHANE IN [bmim][BF4] (cont.)

10 oC 90 min JMC Q4 Bucket

Mass Sample Sample Reading Temperature Pressure Gas Density Mole Fraction (mg) (oC) (bar) (g / cm3) of Gas Wt % Gas 50.46287 10.11 0.011004 7.48E-06 5.08E-05 3.60E-04 50.4627 10.034 0.048238 3.28E-05 1.75E-04 1.24E-03 50.46226 10.014 0.100448 6.83E-05 2.93E-04 2.08E-03 50.45787 9.986 0.498754 3.39E-04 9.06E-04 6.42E-03 50.45159 10.005 0.999007 6.80E-04 1.47E-03 1.04E-02 50.43248 9.957 2.498116 1.71E-03 3.09E-03 2.19E-02 50.41199 9.99 3.999011 2.74E-03 4.37E-03 3.11E-02 50.39051 10.029 5.499356 3.78E-03 5.41E-03 3.85E-02 50.36772 9.995 6.997503 4.83E-03 6.14E-03 4.37E-02 50.34594 10.034 8.492629 5.88E-03 7.16E-03 5.10E-02 50.32394 10.043 9.991874 6.93E-03 8.18E-03 5.83E-02 50.31073 10 10.99856 7.65E-03 9.33E-03 6.66E-02 50.29575 10 12.00443 8.37E-03 1.00E-02 7.15E-02 50.28195 9.971 12.99174 9.08E-03 1.09E-02 7.82E-02 50.28195 9.971 12.99174 9.08E-03 1.09E-02 7.82E-02 50.32223 10.082 10.99829 7.65E-03 1.25E-02 8.93E-02 50.35639 10 9.000712 6.23E-03 1.24E-02 8.89E-02 50.40641 10.043 5.99796 4.13E-03 1.21E-02 8.67E-02 50.41931 10.043 4.998005 3.43E-03 1.10E-02 7.88E-02 50.43879 9.99 3.496285 2.39E-03 9.44E-03 6.74E-02 50.45577 10.038 1.999374 1.36E-03 7.24E-03 5.16E-02 50.46827 10 0.498617 3.39E-04 3.80E-03 2.70E-02 50.46382 9.976 0.010592 7.20E-06 3.15E-04 2.23E-03

228 TABLE D-21 METHANE IN [bmim][BF4] (cont.)

25 oC 90 min Welton Q4 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 75.78446 25.978 0 0.00E+00 0.00E+00 0.00E+00 75.78487 25.064 0.0066 4.26E-06 1.16E-04 8.22E-04 75.78487 25.079 0.0483 3.12E-05 3.67E-04 2.60E-03 75.78301 25.077 0.1968 1.27E-04 9.13E-04 6.47E-03 75.77456 25.070 0.5975 3.86E-04 1.75E-03 1.24E-02 75.76734 25.075 0.9974 6.45E-04 2.81E-03 1.99E-02 75.73724 25.075 1.9978 1.29E-03 3.25E-03 2.30E-02 75.70858 25.075 2.9973 1.94E-03 3.96E-03 2.81E-02 75.67765 25.081 3.9977 2.60E-03 4.28E-03 3.04E-02 75.6463 25.075 4.9987 3.25E-03 4.56E-03 3.24E-02 75.61662 25.066 5.9986 3.91E-03 5.15E-03 3.66E-02 75.5863 25.079 6.9987 4.57E-03 5.64E-03 4.02E-02 75.55558 25.073 7.9985 5.23E-03 6.09E-03 4.33E-02 75.52485 25.075 8.9984 5.90E-03 6.55E-03 4.66E-02 75.4933 25.079 9.9991 6.57E-03 6.89E-03 4.90E-02 75.46382 25.070 10.9978 7.24E-03 7.61E-03 5.43E-02 75.43309 25.070 11.9985 7.91E-03 8.14E-03 5.81E-02 75.40031 25.077 12.999 8.58E-03 8.32E-03 5.93E-02 75.40031 25.128 12.9992 8.58E-03 8.30E-03 5.92E-02 75.40752 25.079 12.4993 8.25E-03 6.54E-03 4.66E-02 75.44113 25.075 11.4982 7.57E-03 6.53E-03 4.65E-02 75.47228 25.077 10.4993 6.90E-03 6.10E-03 4.34E-02 75.50196 25.077 9.498 6.23E-03 5.40E-03 3.84E-02 75.53227 25.079 8.4982 5.57E-03 4.85E-03 3.45E-02 75.563 25.081 7.4988 4.90E-03 4.40E-03 3.13E-02 75.5929 25.075 6.4983 4.24E-03 3.81E-03 2.71E-02 75.62238 25.090 5.4977 3.58E-03 3.16E-03 2.25E-02 75.65126 25.075 4.4981 2.93E-03 2.43E-03 1.73E-02 75.67971 25.081 3.4976 2.27E-03 1.64E-03 1.16E-02 75.70755 25.075 2.4981 1.62E-03 7.54E-04 5.34E-03 75.73786 25.077 1.4985 9.70E-04 3.50E-04 2.48E-03 75.76961 25.073 0.499 3.22E-04 2.36E-04 1.67E-03 75.77456 25.073 0.0953 6.15E-05 -1.27E-03 -9.01E-03

229 TABLE D-21 METHANE IN [bmim][BF4] (cont.)

25 oC 90 min JMC Q4 Bucket

Mass Sample Sample Reading Temperature Pressure Gas Density Mole Fraction (mg) (oC) (bar) (g / cm3) of Gas Wt % Gas 50.34107 29.604 0.0007 4.45E-07 3.06E-06 2.17E-05 50.33782 25.004 0.015264 9.85E-06 -8.45E-04 -5.98E-03 50.3376 24.951 0.050436 3.26E-05 -7.50E-04 -5.31E-03 50.33709 25.009 0.100311 6.48E-05 -6.72E-04 -4.75E-03 50.33209 24.98 0.498754 3.22E-04 -3.03E-04 -2.15E-03 50.32578 24.97 0.998732 6.46E-04 1.52E-04 1.08E-03 50.30735 25.009 2.497566 1.62E-03 1.67E-03 1.19E-02 50.28706 24.999 3.997912 2.60E-03 2.71E-03 1.93E-02 50.26729 24.99 5.496471 3.58E-03 3.93E-03 2.79E-02 50.24624 25.009 6.998053 4.57E-03 4.83E-03 3.43E-02 50.22584 25.009 8.510215 5.58E-03 5.99E-03 4.26E-02 50.2045 25.048 10.00616 6.57E-03 6.84E-03 4.88E-02 50.19241 25.043 11.00021 7.24E-03 8.01E-03 5.71E-02 50.17838 25.043 11.99838 7.91E-03 8.68E-03 6.19E-02 50.16368 25.038 12.9769 8.57E-03 9.09E-03 6.49E-02 50.16368 25.038 12.9769 8.57E-03 9.09E-03 6.49E-02 50.19603 24.985 11.0031 7.24E-03 9.04E-03 6.45E-02 50.22456 24.961 9.001674 5.90E-03 7.86E-03 5.60E-02 50.26802 24.97 5.997823 3.91E-03 6.38E-03 4.54E-02 50.27928 24.999 4.998005 3.25E-03 5.03E-03 3.57E-02 50.29744 25.062 3.49917 2.27E-03 3.38E-03 2.40E-02 50.31606 24.985 1.9991 1.29E-03 1.89E-03 1.34E-02 50.33231 25.028 0.498754 3.22E-04 -2.42E-04 -1.71E-03 50.33757 24.961 0.011004 7.10E-06 -9.34E-04 -6.61E-03 50.46717 24.585 0.000425 2.75E-07 3.42E-02 2.50E-01

230 TABLE D-21 METHANE IN [bmim][BF4] (cont.)

25 oC 90 min JMC Q4 Bucket

Mass Sample Sample Reading Temperature Pressure Gas Density Mole Fraction (mg) (oC) (bar) (g / cm3) of Gas Wt % Gas 76.66974 28.972 0.000562 3.58E-07 3.06E-06 2.17E-05 76.65701 25.004 0.01018 6.57E-06 -2.29E-03 -1.62E-02 76.6459 24.98 0.049475 3.19E-05 -4.14E-03 -2.92E-02 76.64854 25.052 0.099211 6.40E-05 -3.37E-03 -2.38E-02 76.64409 24.99 0.499578 3.23E-04 -1.97E-03 -1.39E-02 76.63134 25.028 0.999007 6.46E-04 -1.56E-03 -1.10E-02 76.59035 25.023 2.497704 1.62E-03 -7.90E-04 -5.59E-03 76.55207 25.033 3.997912 2.60E-03 5.26E-04 3.73E-03 76.51676 24.99 5.495784 3.58E-03 2.42E-03 1.72E-02 76.48272 25.028 6.993931 4.57E-03 4.58E-03 3.25E-02 76.40977 25.096 8.503482 5.57E-03 -2.99E-04 -2.11E-03 76.38043 25.009 9.99792 6.57E-03 2.82E-03 2.00E-02 76.36301 25.004 11.00626 7.24E-03 5.36E-03 3.81E-02 76.34478 25.052 11.99426 7.91E-03 7.64E-03 5.44E-02 76.32752 24.961 13.00548 8.59E-03 1.03E-02 7.33E-02 76.32752 24.961 13.00548 8.59E-03 1.03E-02 7.33E-02 76.39742 24.961 10.99636 7.24E-03 1.15E-02 8.26E-02 76.45923 24.966 8.997277 5.90E-03 1.15E-02 8.24E-02 76.54726 24.999 5.998098 3.91E-03 1.08E-02 7.69E-02 76.57423 24.999 4.996356 3.25E-03 1.01E-02 7.22E-02 76.61487 24.946 3.497796 2.27E-03 9.22E-03 6.58E-02 76.65016 25.023 1.99855 1.29E-03 7.40E-03 5.27E-02 76.68014 25.043 0.499441 3.23E-04 4.65E-03 3.31E-02 76.68118 25.019 0.010317 6.66E-06 2.16E-03 1.53E-02

231 TABLE D-21 METHANE IN [bmim][BF4] (cont.)

50 oC 90 min Welton Q4 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density (g Fraction of (mg) (oC) (bar) / cm3) Gas Wt % Gas 75.80632 50.054 2.00E-04 1.19E-07 1.13E-06 7.99E-06 75.79127 50.008 9.00E-03 5.36E-06 -2.76E-03 -1.95E-02 75.78859 50.024 4.84E-02 2.88E-05 -3.04E-03 -2.15E-02 75.78755 50.019 1.96E-01 1.17E-04 -2.40E-03 -1.69E-02 75.78033 50.008 5.98E-01 3.56E-04 -1.47E-03 -1.04E-02 75.77395 50.019 9.98E-01 5.95E-04 -3.92E-04 -2.77E-03 75.75064 50.019 2.00E+00 1.19E-03 9.30E-04 6.59E-03 75.71415 50.019 3.00E+00 1.79E-03 -1.87E-04 -1.32E-03 75.66425 50.092 4.00E+00 2.39E-03 -3.81E-03 -2.69E-02 75.66157 50.031 5.00E+00 3.00E-03 1.43E-03 1.01E-02 75.63125 50.019 6.00E+00 3.60E-03 1.50E-03 1.06E-02 75.60403 50.019 7.00E+00 4.21E-03 2.17E-03 1.54E-02 75.57599 50.01 8.00E+00 4.81E-03 2.70E-03 1.91E-02 75.54836 50.022 9.00E+00 5.42E-03 3.31E-03 2.35E-02 75.52341 50.006 1.00E+01 6.03E-03 4.44E-03 3.16E-02 75.49248 50.017 1.10E+01 6.64E-03 4.47E-03 3.18E-02 75.45949 50.019 1.20E+01 7.26E-03 4.15E-03 2.95E-02 75.43639 50.004 1.30E+01 7.87E-03 5.67E-03 4.03E-02 75.43619 50 1.30E+01 7.87E-03 5.63E-03 4.01E-02 75.4465 50.019 1.25E+01 7.57E-03 4.64E-03 3.30E-02 75.47557 50.017 1.15E+01 6.95E-03 4.24E-03 3.01E-02 75.50836 50.024 1.05E+01 6.34E-03 4.53E-03 3.22E-02 75.53433 50.015 9.50E+00 5.73E-03 3.59E-03 2.55E-02 75.55888 50.017 8.50E+00 5.12E-03 2.39E-03 1.70E-02 75.59063 50.019 7.50E+00 4.51E-03 2.54E-03 1.80E-02 75.62053 50.019 6.50E+00 3.90E-03 2.36E-03 1.67E-02 75.6494 50.008 5.50E+00 3.30E-03 2.02E-03 1.43E-02 75.6564 50.01 4.50E+00 2.69E-03 -2.40E-03 -1.70E-02 75.68074 50.019 3.50E+00 2.09E-03 -3.58E-03 -2.52E-02 75.71869 50.024 2.50E+00 1.49E-03 -2.19E-03 -1.54E-02 75.74405 50.026 1.50E+00 8.94E-04 -3.14E-03 -2.21E-02 75.77168 50.022 4.99E-01 2.97E-04 -3.65E-03 -2.58E-02 75.77683 50.019 9.46E-02 5.63E-05 -4.99E-03 -3.51E-02 75.78014 49.846 3.10E-03 1.85E-06 -4.89E-03 -3.44E-02

232 TABLE D-21 METHANE IN [bmim][BF4] (cont.)

50 oC 120 min Welton Q4 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 75.64692 49.965 0 0.00E+00 0.00E+00 0.00E+00 75.64672 50.013 0.0138 8.22E-06 4.05E-05 2.87E-04 75.64672 50.019 0.0501 2.98E-05 2.45E-04 1.74E-03 75.64652 50.019 0.099 5.90E-05 4.84E-04 3.43E-03 75.64115 50.019 0.5016 2.99E-04 1.75E-03 1.24E-02 75.62837 50.015 1.0015 5.97E-04 2.19E-03 1.55E-02 75.6162 50.019 1.5012 8.96E-04 2.74E-03 1.95E-02 75.60548 50.019 2.0012 1.19E-03 3.57E-03 2.53E-02 75.5929 50.019 2.5014 1.49E-03 4.05E-03 2.88E-02 75.57001 50.015 2.9966 1.79E-03 2.60E-03 1.85E-02 75.52155 50.015 3.9965 2.39E-03 -7.47E-04 -5.28E-03 75.64073 49.962 0.0004 2.38E-07 -1.16E-03 -8.17E-03 75.64136 50.131 0.0127 7.56E-06 -9.68E-04 -6.84E-03 75.64156 50.05 0.0504 3.00E-05 -7.17E-04 -5.07E-03 75.64156 50.019 0.1991 1.19E-04 1.23E-04 8.68E-04 75.63703 50.013 0.6007 3.58E-04 1.54E-03 1.09E-02 75.62692 49.998 1.0017 5.97E-04 1.92E-03 1.36E-02 75.6028 50.002 2.0016 1.20E-03 3.07E-03 2.18E-02 75.57475 49.984 3.0021 1.80E-03 3.52E-03 2.50E-02 75.52918 50.024 4.0022 2.40E-03 7.10E-04 5.03E-03 75.51785 49.962 5.0027 3.00E-03 4.29E-03 3.05E-02 75.48856 49.978 6.0017 3.60E-03 4.54E-03 3.23E-02 75.46134 49.991 7.0025 4.21E-03 5.19E-03 3.69E-02 75.43227 49.978 8.0025 4.82E-03 5.52E-03 3.92E-02 75.40402 49.978 9.0021 5.43E-03 6.00E-03 4.27E-02 75.37907 49.984 10.003 6.04E-03 7.12E-03 5.07E-02 75.3471 49.986 11.0016 6.65E-03 6.94E-03 4.94E-02 75.31762 49.984 12.0019 7.26E-03 7.25E-03 5.16E-02 75.28422 50.002 13.0026 7.88E-03 6.84E-03 4.87E-02 75.28422 49.995 13.0023 7.88E-03 6.84E-03 4.87E-02 75.30256 50.035 12.5031 7.57E-03 7.34E-03 5.23E-02 75.32938 50.033 11.5027 6.95E-03 6.54E-03 4.65E-02 75.36175 50.054 10.5014 6.34E-03 6.76E-03 4.82E-02 75.38691 50.061 9.5018 5.73E-03 5.68E-03 4.04E-02 75.41949 50.035 8.5019 5.12E-03 5.99E-03 4.27E-02 75.44877 50.006 7.503 4.51E-03 5.72E-03 4.07E-02 75.47413 50.046 6.5017 3.90E-03 4.70E-03 3.34E-02 75.50568 50.059 5.5022 3.30E-03 4.86E-03 3.46E-02 75.52279 50.107 4.502 2.70E-03 2.36E-03 1.67E-02 75.54485 50.052 3.5013 2.09E-03 7.81E-04 5.53E-03 75.57909 50.026 2.5024 1.50E-03 1.50E-03 1.06E-02

233 TABLE D-21 METHANE IN [bmim][BF4] (cont.)

75.59496 50.065 1.5014 8.96E-04 -1.22E-03 -8.62E-03 75.62403 50.052 0.5029 3.00E-04 -1.44E-03 -1.02E-02 75.63249 50.033 0.0987 5.88E-05 -2.14E-03 -1.51E-02 75.63579 49.201 0.0048 2.87E-06 -2.06E-03 -1.45E-02

50 oC JMC Welton Q4 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 50.39965 50.101 0.000562 3.35E-07 2.36E-06 1.67E-05 50.39687 49.994 0.011142 6.64E-06 -7.33E-04 -5.19E-03 50.39724 49.994 0.048238 2.87E-05 -4.73E-04 -3.35E-03 50.39692 50.003 0.098799 5.88E-05 -3.51E-04 -2.48E-03 50.39384 50.033 0.499029 2.97E-04 4.66E-04 3.30E-03 50.38921 49.994 0.999144 5.96E-04 1.27E-03 8.99E-03 50.37159 49.989 2.498253 1.49E-03 2.64E-03 1.87E-02 50.34966 49.96 3.999698 2.39E-03 2.85E-03 2.02E-02 50.32309 50.003 5.493723 3.30E-03 1.75E-03 1.24E-02 50.31337 50.003 6.999015 4.21E-03 5.42E-03 3.85E-02 50.29873 50.047 8.496201 5.12E-03 7.69E-03 5.48E-02 50.28369 49.984 9.997096 6.03E-03 9.89E-03 7.06E-02 50.27189 50.037 11.00749 6.65E-03 1.09E-02 7.80E-02 50.25856 49.994 11.99824 7.26E-03 1.14E-02 8.19E-02 50.23284 49.979 12.99806 7.87E-03 8.63E-03 6.16E-02 50.23284 49.979 12.99806 7.87E-03 8.63E-03 6.16E-02 50.27385 50.003 10.99458 6.64E-03 1.14E-02 8.15E-02 50.28163 49.999 8.997553 5.42E-03 5.08E-03 3.61E-02 50.31993 50.091 6.003869 3.60E-03 3.02E-03 2.14E-02 50.3329 49.994 4.997867 3.00E-03 2.39E-03 1.69E-02 50.35466 49.969 3.498621 2.09E-03 2.13E-03 1.51E-02 50.37323 49.974 2.001985 1.20E-03 1.01E-03 7.18E-03 50.38972 49.974 0.499166 2.97E-04 -6.89E-04 -4.87E-03 50.39056 50.062 0.011004 6.55E-06 -2.51E-03 -1.77E-02

234 TABLE D-22 METHANE IN [bmim][Tf2N]

10 oC 90 min Covalent Q1 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density (g / Fraction Wt % (mg) (oC) (bar) cm3) of Gas Gas 51.68819 12.759 0.021996 1.48E-05 1.58E-05 6.05E-05 51.68824 9.88 0.046589 3.18E-05 5.92E-05 2.26E-04 51.68819 9.962 0.10141 6.91E-05 7.38E-05 2.82E-04 51.68954 10.019 0.500128 3.42E-04 1.05E-03 4.01E-03 51.69108 10 0.999556 6.82E-04 2.18E-03 8.37E-03 51.69438 10.005 2.497291 1.71E-03 4.93E-03 1.90E-02 51.69607 9.986 3.996675 2.75E-03 6.87E-03 2.64E-02 51.69886 10.058 5.501692 3.79E-03 9.35E-03 3.61E-02 51.69923 10.038 7.004099 4.84E-03 1.06E-02 4.11E-02 51.69876 10.038 8.495788 5.89E-03 1.15E-02 4.45E-02 51.6972 10.014 9.999844 6.96E-03 1.18E-02 4.58E-02 51.69526 10.038 10.99636 7.67E-03 1.16E-02 4.49E-02 51.69512 9.962 11.99962 8.39E-03 1.23E-02 4.76E-02 51.69421 9.986 12.98927 9.10E-03 1.26E-02 4.87E-02 51.69421 9.986 12.98927 9.10E-03 1.26E-02 4.87E-02 51.69725 10.014 10.99581 7.67E-03 1.26E-02 4.88E-02 51.69905 10 6.007303 4.15E-03 9.82E-03 3.79E-02 51.69541 9.966 1.998825 1.37E-03 5.09E-03 1.95E-02 51.69025 10.019 0.198273 1.35E-04 1.18E-03 4.54E-03 51.68885 9.995 0.073244 4.99E-05 3.87E-04 1.48E-03 51.68887 10 0.019935 1.36E-05 3.58E-04 1.37E-03

235 TABLE D-22 METHANE IN [bmim][Tf2N] (cont.)

10 oC 120 min Covalent Q1 Bucket

Mass Sample Sample Gas Reading Temperature Pressure Density (g / Mole Fraction (mg) (oC) (bar) cm3) of Gas Wt % Gas 51.72167 27.858 0.0007 4.49E-07 4.84E-07 1.85E-06 51.71814 9.933 0.012378 8.44E-06 -1.78E-03 -6.79E-03 51.71878 9.995 0.046727 3.18E-05 -1.43E-03 -5.46E-03 51.71886 9.962 0.098524 6.72E-05 -1.35E-03 -5.16E-03 51.71991 10.024 0.500403 3.41E-04 -5.22E-04 -2.00E-03 51.72091 10.048 0.999968 6.83E-04 3.52E-04 1.35E-03 51.72453 10.029 2.499077 1.71E-03 3.28E-03 1.26E-02 51.72548 9.99 3.998599 2.75E-03 4.87E-03 1.87E-02 51.72693 10.014 5.508836 3.80E-03 6.71E-03 2.58E-02 51.72879 10.019 6.992833 4.84E-03 8.74E-03 3.37E-02 51.72813 10.024 8.494827 5.89E-03 9.53E-03 3.68E-02 51.7282 10.029 10.00424 6.96E-03 1.07E-02 4.13E-02 51.72937 10.01 10.9884 7.66E-03 1.20E-02 4.65E-02 51.72779 10.029 11.99866 8.38E-03 1.20E-02 4.64E-02 51.72593 10.053 12.99985 9.10E-03 1.18E-02 4.58E-02 51.72593 10.053 12.99985 9.10E-03 1.18E-02 4.58E-02 51.72326 10.048 11.00887 7.68E-03 9.00E-03 3.47E-02 51.72248 10.005 5.987518 4.13E-03 4.84E-03 1.86E-02 51.71736 9.986 1.998687 1.37E-03 -7.05E-04 -2.69E-03 51.71237 10.034 0.198273 1.35E-04 -4.58E-03 -1.74E-02 51.71146 10.038 0.072694 4.95E-05 -5.13E-03 -1.95E-02 51.71141 9.981 0.020759 1.41E-05 -5.20E-03 -1.98E-02

236 TABLE D-22 METHANE IN [bmim][Tf2N] (cont.)

10 oC 180 min Covalent Q1 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 51.70378 30.627 0.0007 4.45E-07 4.77E-07 1.82E-06 51.70055 10.048 0.008669 5.91E-06 -1.63E-03 -6.22E-03 51.7007 9.957 0.047963 3.27E-05 -1.52E-03 -5.82E-03 51.70121 10.01 0.09825 6.70E-05 -1.23E-03 -4.70E-03 51.70258 10.005 0.50054 3.41E-04 -2.41E-04 -9.21E-04 51.70393 9.995 0.998869 6.82E-04 8.06E-04 3.09E-03 51.70787 10.01 2.498528 1.71E-03 3.89E-03 1.49E-02 51.70956 10.043 3.998186 2.75E-03 5.83E-03 2.24E-02 51.71085 9.976 5.506913 3.80E-03 7.59E-03 2.92E-02 51.71308 10.034 6.997779 4.84E-03 9.79E-03 3.78E-02 51.7134 9.938 8.491666 5.89E-03 1.11E-02 4.27E-02 51.71369 10.067 9.999981 6.96E-03 1.23E-02 4.77E-02 51.71359 9.952 10.99444 7.67E-03 1.30E-02 5.04E-02 51.71501 10.029 11.98327 8.37E-03 1.44E-02 5.60E-02 51.71278 10.048 12.99422 9.10E-03 1.41E-02 5.47E-02 51.71278 10.048 12.99422 9.10E-03 1.41E-02 5.47E-02 51.71303 9.966 10.9987 7.67E-03 1.27E-02 4.93E-02 51.71149 9.966 6.000708 4.14E-03 8.27E-03 3.19E-02 51.70432 10.014 1.998962 1.37E-03 1.74E-03 6.65E-03 51.69923 9.976 0.197998 1.35E-04 -2.16E-03 -8.25E-03 51.69879 10.005 0.071733 4.89E-05 -2.48E-03 -9.45E-03 51.69901 10.029 0.02282 1.55E-05 -2.40E-03 -9.16E-03

237 TABLE D-22 METHANE IN [bmim][Tf2N] (cont.)

10 oC 180 min Covalent Q1 Bucket

Mass Sample Sample Mole Reading Temperature Pressure Gas Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 51.71281 16.693 0.000562 3.74E-07 4.02E-07 1.54E-06 51.7087 10.053 0.011279 7.68E-06 -2.07E-03 -7.92E-03 51.70863 9.981 0.048238 3.29E-05 -2.08E-03 -7.95E-03 51.70884 10.038 0.098524 6.71E-05 -1.94E-03 -7.40E-03 51.71066 9.995 0.499166 3.40E-04 -7.21E-04 -2.76E-03 51.71303 10.053 0.999694 6.82E-04 8.44E-04 3.23E-03 51.71866 10.024 2.499352 1.71E-03 4.78E-03 1.83E-02 51.72116 10.019 3.998324 2.75E-03 7.12E-03 2.74E-02 51.72367 9.986 5.499082 3.79E-03 9.48E-03 3.66E-02 51.72514 10.019 7.008908 4.85E-03 1.13E-02 4.38E-02

25 oC 90 min Covalent Q1 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 51.69331 34.94 0.0007 4.38E-07 5.43E-07 2.08E-06 51.69118 24.961 0.012516 8.10E-06 -1.07E-03 -4.08E-03 51.69113 24.995 0.048513 3.14E-05 -1.06E-03 -4.07E-03 51.6912 25.038 0.098799 6.40E-05 -9.89E-04 -3.78E-03 51.69306 24.995 0.498891 3.22E-04 2.74E-04 1.05E-03 51.69492 24.966 0.999694 6.48E-04 1.62E-03 6.19E-03 51.69879 25.009 2.498253 1.62E-03 4.76E-03 1.83E-02 51.70031 25.004 3.998461 2.61E-03 6.73E-03 2.59E-02 51.70236 24.966 5.498395 3.59E-03 8.96E-03 3.46E-02 51.70251 25.014 6.997641 4.58E-03 1.02E-02 3.95E-02 51.70385 25.048 8.491255 5.58E-03 1.21E-02 4.68E-02 51.70452 25.052 9.99737 6.58E-03 1.37E-02 5.29E-02 51.70578 24.97 10.99952 7.26E-03 1.51E-02 5.85E-02 51.70518 24.956 11.99495 7.93E-03 1.56E-02 6.06E-02 51.70608 25.023 12.98666 8.60E-03 1.68E-02 6.55E-02 51.70608 25.023 12.98666 8.60E-03 1.68E-02 6.55E-02 51.70544 24.98 11.01313 7.27E-03 1.49E-02 5.79E-02 51.70464 25.052 10.9807 7.24E-03 1.45E-02 5.63E-02 51.70417 25.048 2.854654 1.86E-03 7.74E-03 2.98E-02 51.68929 25.038 0.198273 1.28E-04 -1.88E-03 -7.17E-03 51.68831 24.995 0.072145 4.67E-05 -2.48E-03 -9.45E-03 51.68839 24.99 0.028591 2.84E-05 -2.46E-03 -9.38E-03

238 TABLE D-22 METHANE IN [bmim][Tf2N] (cont.)

25 oC 120 min Covalent Q1 Bucket

Mass Sample Sample Gas Reading Temperature Pressure Density Mole Fraction (mg) (oC) (bar) (g / cm3) of Gas Wt % Gas 51.71171 24.416 0.02969 1.93E-05 2.40E-05 9.18E-05 51.71103 25.043 0.049337 3.19E-05 -3.04E-04 -1.16E-03 51.71036 24.995 0.098799 6.39E-05 -6.03E-04 -2.31E-03 51.71237 24.985 0.499853 3.24E-04 7.37E-04 2.82E-03 51.71344 25.009 0.999007 6.48E-04 1.68E-03 6.43E-03 51.71687 24.999 2.499077 1.62E-03 4.61E-03 1.77E-02 51.71832 24.995 3.999011 2.61E-03 6.55E-03 2.52E-02 51.72179 24.985 5.499356 3.59E-03 9.49E-03 3.66E-02 51.72304 24.975 7.000114 4.59E-03 1.13E-02 4.38E-02 51.72463 24.999 8.49785 5.58E-03 1.33E-02 5.16E-02 51.72314 25.038 9.999568 6.58E-03 1.38E-02 5.35E-02 51.7224 25.023 10.99719 7.25E-03 1.42E-02 5.52E-02 51.72167 25.038 11.99907 7.93E-03 1.47E-02 5.71E-02 51.72216 24.999 13.00108 8.61E-03 1.58E-02 6.12E-02 51.72216 24.999 13.00108 8.61E-03 1.58E-02 6.12E-02 51.7226 24.961 10.99375 7.25E-03 1.43E-02 5.56E-02 51.71733 24.995 5.999334 3.92E-03 7.68E-03 2.96E-02 51.7122 24.97 1.998413 1.30E-03 1.86E-03 7.14E-03 51.70762 24.995 0.197998 1.28E-04 -1.91E-03 -7.30E-03 51.70723 25.028 0.072969 4.72E-05 -2.21E-03 -8.44E-03 51.70689 24.975 0.020622 1.33E-05 -2.43E-03 -9.26E-03

239 TABLE D-22 METHANE IN [bmim][Tf2N] (cont.)

50 oC 90 min Covalent Q1 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 51.68939 45.797 0.01966 1.19E-05 1.82E-05 6.97E-05 51.68927 50.013 0.047963 2.87E-05 -1.67E-05 -6.37E-05 51.68951 50.003 0.102509 6.13E-05 1.55E-04 5.92E-04 51.69127 50.018 0.498891 2.98E-04 1.41E-03 5.39E-03 51.69318 50.003 0.999281 5.97E-04 2.82E-03 1.08E-02 51.69531 50.018 2.498802 1.50E-03 5.26E-03 2.02E-02 51.69538 50.008 4.009728 2.41E-03 6.68E-03 2.57E-02 51.68848 49.994 5.502104 3.31E-03 4.60E-03 1.77E-02 51.69583 49.969 6.997229 4.22E-03 9.63E-03 3.72E-02 51.69901 50.033 8.498536 5.13E-03 1.26E-02 4.87E-02 51.71156 50.042 9.999568 6.05E-03 2.01E-02 7.83E-02 51.70808 50.018 10.99801 6.66E-03 1.93E-02 7.52E-02 51.70481 50.028 11.99577 7.27E-03 1.86E-02 7.25E-02 51.71215 50.033 13.00136 7.89E-03 2.31E-02 9.03E-02 51.71215 50.033 13.00136 7.89E-03 2.31E-02 9.03E-02 51.71675 50.037 10.99788 6.66E-03 2.35E-02 9.19E-02 51.68902 50.042 6.000296 3.61E-03 5.32E-03 2.05E-02 51.69399 50.023 1.999237 1.20E-03 4.15E-03 1.59E-02 51.6878 49.994 0.198273 1.18E-04 -6.23E-04 -2.38E-03 51.68734 50.003 0.07558 4.51E-05 -9.69E-04 -3.70E-03 51.6879 50.028 0.01966 1.17E-05 -7.36E-04 -2.81E-03 51.67625 27.332 0.001112 7.14E-07 -6.69E-03 -2.54E-02

240 TABLE D-22 METHANE IN [bmim][Tf2N] (cont.)

50 oC 180 min Covalent Q1 Bucket

Mass Sample Sample Gas Reading Temperature Pressure Density Mole Fraction (mg) (oC) (bar) (g / cm3) of Gas Wt % Gas 51.70336 48.814 0.000425 2.55E-07 3.92E-07 1.50E-06 51.70153 49.999 0.0165 9.85E-06 -9.11E-04 -3.48E-03 51.70172 49.989 0.048101 2.87E-05 -7.86E-04 -3.00E-03 51.70229 50.047 0.098387 5.87E-05 -4.51E-04 -1.72E-03 51.70446 50.008 0.500265 2.99E-04 1.02E-03 3.89E-03 51.70586 50.013 1.000106 5.98E-04 2.18E-03 8.35E-03 51.70704 50.013 2.49949 1.50E-03 4.15E-03 1.59E-02 51.70904 50.008 3.998324 2.40E-03 6.52E-03 2.51E-02 51.70339 49.95 5.50128 3.31E-03 5.08E-03 1.95E-02 51.71905 50.023 6.995992 4.22E-03 1.42E-02 5.51E-02 51.71545 49.999 8.482599 5.12E-03 1.38E-02 5.35E-02 51.72184 49.974 9.994348 6.05E-03 1.83E-02 7.13E-02 51.72784 50.028 10.99911 6.66E-03 2.21E-02 8.65E-02 51.7318 49.979 11.99921 7.28E-03 2.49E-02 9.77E-02 51.72593 50.003 13.00205 7.90E-03 2.30E-02 9.00E-02 51.72593 50.003 13.00205 7.90E-03 2.30E-02 9.00E-02 51.72049 50.013 10.99156 6.66E-03 1.86E-02 7.23E-02 51.70946 50.037 6.000434 3.61E-03 8.57E-03 3.30E-02 51.70498 49.984 1.999787 1.20E-03 2.65E-03 1.02E-02

241 TABLE D-22 METHANE IN [bmim][Tf2N] (cont.)

50 oC 180 min Covalent Q1 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 51.62586 49.567 0.000425 2.54E-07 3.84E-07 1.47E-06 51.62307 50.11 0.012516 7.47E-06 -1.40E-03 -5.36E-03 51.62344 49.999 0.048238 2.88E-05 -1.18E-03 -4.52E-03 51.62197 49.984 0.100036 5.97E-05 -1.88E-03 -7.19E-03 51.62405 50.008 0.499716 2.99E-04 -4.65E-04 -1.78E-03 51.62552 49.926 0.999144 5.97E-04 7.31E-04 2.80E-03 51.62598 49.974 2.497291 1.50E-03 2.32E-03 8.89E-03 51.62016 49.974 3.998186 2.40E-03 7.44E-04 2.85E-03 51.62603 49.955 5.499082 3.31E-03 5.07E-03 1.95E-02 51.63602 50.013 6.997779 4.22E-03 1.14E-02 4.41E-02 51.63496 49.921 8.496201 5.13E-03 1.22E-02 4.73E-02 51.63046 49.999 10.00424 6.05E-03 1.14E-02 4.39E-02 51.63883 49.902 10.99994 6.66E-03 1.64E-02 6.37E-02 51.63729 49.902 11.99783 7.28E-03 1.65E-02 6.42E-02 51.64487 49.979 12.99861 7.89E-03 2.11E-02 8.24E-02 51.64487 49.979 12.99861 7.89E-03 2.11E-02 8.24E-02 51.64473 49.974 11.00475 6.67E-03 1.93E-02 7.51E-02 51.62885 49.945 6.007028 3.62E-03 6.94E-03 2.67E-02 51.62202 49.955 1.998687 1.20E-03 -1.34E-04 -5.12E-04 51.61796 49.95 0.197861 1.18E-04 -3.84E-03 -1.46E-02 51.61754 50.086 0.072832 4.35E-05 -4.17E-03 -1.59E-02 51.61766 49.916 0.022408 1.34E-05 -4.15E-03 -1.58E-02

242 TABLE D-23 NITROUS OXIDE IN [bmim][Tf2N]

10 oC 90 min Covalent Q1 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction Wt % (mg) (oC) (bar) (g / cm3) of Gas Gas 51.67706 13.225 0.020072 3.71E-05 1.44E-05 1.51E-04 51.68352 10.029 0.044666 8.35E-05 1.22E-03 1.28E-02 51.69546 9.947 0.098662 1.85E-04 0.003 0.04 51.7795 10.043 0.498754 9.33E-04 0.019 0.20 51.89116 10.043 0.999007 1.87E-03 0.039 0.42 52.22449 10.014 2.499352 4.67E-03 0.093 1.07 52.56895 10.029 3.997499 7.47E-03 0.143 1.73 52.91928 10.024 5.496197 1.03E-02 0.189 2.39 53.26784 10.053 7.004923 1.31E-02 0.230 3.04 53.62505 10.01 8.497986 1.59E-02 0.268 3.69 53.9819 9.995 9.994348 1.87E-02 0.302 4.34 54.22012 10.029 10.99856 2.06E-02 0.323 4.77 54.46024 10.034 11.99797 2.24E-02 0.343 5.19 54.71014 10 12.9982 2.43E-02 0.363 5.63 54.71014 10 12.9982 2.43E-02 0.363 5.63 54.23075 9.981 10.99774 2.06E-02 0.324 4.78 53.0553 9.99 5.997823 1.12E-02 0.205 2.64 52.14605 9.986 1.999374 3.74E-03 0.081 0.91 51.74203 9.976 0.19841 3.71E-04 0.012 0.13 51.70312 10.024 0.071183 1.33E-04 0.005 0.05 51.6904 9.981 0.018698 3.50E-05 0.002 0.03

243 TABLE D-23 NITROUS OXIDE IN [bmim][Tf2N] (cont.)

10 oC 180 min Covalent Q4 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction Wt % (mg) (oC) (bar) (g / cm3) of Gas Gas 84.51579 15.084 0.014164 2.60E-05 1.20E-04 1.26E-03 84.52888 10.173 0.048101 8.99E-05 1.89E-03 1.98E-02 84.544 10.048 0.099349 1.86E-04 0.004 0.04 84.64548 10.125 0.499166 9.33E-04 0.019 0.20 84.78886 9.861 0.998457 1.87E-03 0.038 0.41 85.20858 10.019 2.497704 4.67E-03 0.091 1.04 85.66089 10.067 3.998461 7.48E-03 0.141 1.69 86.1198 10.019 5.498532 1.03E-02 0.186 2.34 86.58353 9.981 6.998603 1.31E-02 0.227 2.99 87.05026 9.981 8.502108 1.59E-02 0.264 3.63 87.52778 9.99 9.997096 1.87E-02 0.299 4.28 87.85235 9.962 10.99719 2.06E-02 0.320 4.71 88.18419 9.976 11.99866 2.24E-02 0.341 5.15 88.50105 10.048 12.99669 2.43E-02 0.360 5.56 88.50105 10.048 12.99669 2.43E-02 0.360 5.56 87.86914 9.971 10.99801 2.06E-02 0.321 4.73 87.23687 9.986 8.996865 1.68E-02 0.278 3.88 86.3114 10.014 5.998647 1.12E-02 0.203 2.60 86.00425 10.043 4.998554 9.35E-03 0.174 2.17 85.55956 9.986 3.499033 6.54E-03 0.129 1.53 85.12057 10.024 1.999374 3.74E-03 0.079 0.89 84.68371 9.928 0.499166 9.34E-04 0.023 0.24 84.53542 10.024 0.010043 1.88E-05 0.002 0.02

244 TABLE D-23 NITROUS OXIDE IN [bmim][Tf2N] (cont.)

25 oC 90 min Covalent Q1 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction (mg) (oC) (bar) (g / cm3) of Gas Wt % Gas 51.67625 27.332 0.001112 1.96E-06 8.82E-07 9.25E-06 51.67715 35.172 0.000837 1.44E-06 1.67E-04 1.75E-03 51.67529 24.913 0.008256 1.47E-05 0.000 0.00 51.6818 25.028 0.06184 1.10E-04 0.001 0.01 51.6902 25.028 0.09825 1.74E-04 0.003 0.03 51.75539 25.019 0.499029 8.86E-04 0.015 0.16 51.83842 24.999 0.999281 1.77E-03 0.030 0.32 52.08556 24.999 2.497978 4.44E-03 0.072 0.81 52.336 25.004 3.997774 7.10E-03 0.111 1.29 52.58841 24.999 5.498257 9.76E-03 0.147 1.78 52.83625 24.966 6.996542 1.24E-02 0.180 2.25 53.08692 25.009 8.497986 1.51E-02 0.211 2.72 53.33085 25.048 9.999294 1.78E-02 0.238 3.18 53.49741 25.028 10.99788 1.95E-02 0.256 3.49 53.66283 25.019 11.99728 2.13E-02 0.273 3.80 53.82648 25.062 12.9982 2.31E-02 0.289 4.10 53.82648 25.062 12.9982 2.31E-02 0.289 4.10 53.49283 25.062 10.99884 1.95E-02 0.256 3.48 52.66716 24.995 5.997411 1.07E-02 0.158 1.93 52.00639 24.985 1.999512 3.55E-03 0.059 0.65 51.7052 25.023 0.198273 3.52E-04 0.005 0.06 51.68349 25.028 0.075854 1.35E-04 1.39E-03 1.46E-02 51.67642 24.99 0.035598 6.32E-05 5.98E-05 6.27E-04

245 TABLE D-23 NITROUS OXIDE IN [bmim][Tf2N] (cont.)

25 oC 180 min Covalent Q4 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 84.47859 28.21 0.000288 5.06E-07 2.37E-06 2.48E-05 84.48009 25.004 0.00963 1.71E-05 2.49E-04 2.62E-03 84.48684 25.009 0.049475 8.79E-05 0.001 0.01 84.49609 25.009 0.099074 1.76E-04 0.003 0.03 84.57269 25.014 0.498891 8.86E-04 0.015 0.15 84.67167 25.009 0.999007 1.77E-03 0.029 0.31 84.96694 25.052 2.497841 4.43E-03 0.071 0.79 85.2671 24.995 4.000522 7.10E-03 0.109 1.27 85.56861 24.932 5.502242 9.77E-03 0.144 1.74 85.86961 24.98 6.997229 1.24E-02 0.177 2.21 86.17661 24.99 8.500734 1.51E-02 0.208 2.68 86.48213 24.995 10.00026 1.78E-02 0.236 3.14 86.68964 24.985 10.99884 1.95E-02 0.254 3.45 86.89737 24.975 11.9966 2.13E-02 0.271 3.76 87.10511 25.052 12.99669 2.31E-02 0.288 4.07 87.10511 25.052 12.99669 2.31E-02 0.288 4.07 86.70177 24.975 10.99911 1.95E-02 0.255 3.47 86.29948 25.009 8.99769 1.60E-02 0.219 2.86 85.69554 25.033 5.998647 1.07E-02 0.158 1.93 85.49786 25.048 4.998554 8.88E-03 0.135 1.62 85.20001 25.038 3.497934 6.21E-03 0.099 1.15 84.90621 25.009 1.998962 3.55E-03 0.061 0.68 84.60915 25.009 0.499029 8.86E-04 1.85E-02 1.98E-01 84.51422 25.004 0.010043 1.78E-05 4.09E-03 4.30E-02

246 TABLE D-23 NITROUS OXIDE IN [bmim][Tf2N] (cont.)

50 oC 90 min Covalent Q1 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 51.68731 44.537 0.025293 4.22E-05 2.36E-05 2.47E-04 51.68978 49.897 0.044803 7.34E-05 4.96E-04 5.21E-03 51.69595 50.018 0.098112 1.61E-04 1.68E-03 1.77E-02 51.7409 49.979 0.500265 8.20E-04 0.010 0.11 51.79641 49.979 0.999419 1.64E-03 0.021 0.22 51.94455 49.994 2.49894 4.09E-03 0.047 0.52 52.12185 50.013 3.998049 6.55E-03 0.077 0.87 52.28843 50.013 5.494136 9.00E-03 0.104 1.20 52.44887 49.994 7.000114 1.15E-02 0.128 1.52 52.60793 50.018 8.495514 1.39E-02 0.151 1.83 52.73666 50.023 9.993661 1.64E-02 0.169 2.08 52.88006 49.969 11.0112 1.80E-02 0.187 2.36 52.9537 50.003 12.00085 1.97E-02 0.196 2.50 53.05038 50.081 13.01015 2.13E-02 0.208 2.69 53.05038 50.081 13.01015 2.13E-02 0.208 2.69 52.84235 49.965 11.00323 1.80E-02 0.182 2.29 52.34178 49.984 6.003456 9.84E-03 0.112 1.31 51.89637 50.003 1.999512 3.28E-03 0.039 0.42 51.70684 50.013 0.19841 3.25E-04 0.004 0.04 51.69353 49.999 0.072145 1.18E-04 1.21E-03 1.27E-02 51.68974 50.013 0.026667 4.37E-05 4.72E-04 4.96E-03

247 TABLE D-23 NITROUS OXIDE IN [bmim][Tf2N] (cont.)

50 oC 180 min Covalent Q4 Bucket

Mass Sample Sample Mole Reading Temperature Pressure Gas Density Fraction (mg) (oC) (bar) (g / cm3) of Gas Wt % Gas 84.51616 50.761 0.000562 9.19E-07 4.40E-06 4.61E-05 84.51833 50.013 0.011004 1.80E-05 3.31E-04 3.47E-03 84.52306 49.999 0.048238 7.90E-05 1.16E-03 1.21E-02 84.52898 50.028 0.099211 1.63E-04 2.22E-03 0.02 84.57528 49.994 0.499578 8.19E-04 0.010 0.11 84.63235 50.033 0.999144 1.64E-03 0.021 0.22 84.79926 50.013 2.499215 4.09E-03 0.049 0.54 84.96225 50.042 3.997637 6.55E-03 0.076 0.85 85.1256 50.018 5.496059 9.00E-03 0.101 1.16 85.27421 50.003 6.998328 1.15E-02 0.123 1.45 85.40874 50.018 8.500597 1.39E-02 0.143 1.73 85.59805 50.037 10.00259 1.64E-02 0.167 2.06 85.6975 49.974 10.99691 1.80E-02 0.180 2.25 85.79108 50.037 11.99769 1.97E-02 0.192 2.44 85.89046 50.042 13.00053 2.13E-02 0.204 2.63 85.89046 50.042 13.00053 2.13E-02 0.204 2.63 85.7091 49.989 10.99403 1.80E-02 0.181 2.26 85.49603 50.008 9.000025 1.47E-02 0.153 1.86 85.15692 50.062 6.002631 9.83E-03 0.107 1.24 85.05324 49.994 5.001165 8.19E-03 0.091 1.04 84.89194 49.994 3.499308 5.73E-03 0.065 0.73 84.73298 49.994 1.999237 3.28E-03 0.039 0.42 84.56708 49.994 0.498891 8.17E-04 9.56E-03 1.01E-01 84.5143 50.003 0.013203 2.16E-05 -1.06E-04 -1.11E-03

248 TABLE D-24 OXYGEN IN [bmim][PF6]

10 oC 90 min Sachem SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 76.75314 17.731 0.0001 1.32E-06 6.56E-06 7.39E-05 76.75025 10.104 0.0079 1.07E-05 -2.81E-04 -3.17E-03 76.74777 10.084 0.0496 6.74E-05 -2.87E-04 -3.23E-03 76.74014 10.079 0.1972 2.68E-04 -1.75E-04 -1.97E-03 76.71783 10.079 0.5985 8.14E-04 -5.10E-05 -5.75E-04 76.69492 10.084 0.999 1.36E-03 1.88E-08 2.12E-07 76.63648 10.082 1.998 2.72E-03 -1.44E-05 -1.62E-04 76.58011 10.077 2.997 4.08E-03 2.22E-04 2.50E-03 76.52146 10.084 3.9985 5.45E-03 2.21E-04 2.49E-03 76.46426 10.079 4.9983 6.82E-03 3.89E-04 4.38E-03 76.40562 10.079 5.9981 8.19E-03 4.01E-04 4.51E-03 76.34512 10.077 6.9989 9.56E-03 2.15E-04 2.42E-03 76.2869 10.084 7.9989 1.09E-02 2.97E-04 3.35E-03 76.22866 10.079 8.9985 1.23E-02 3.87E-04 4.36E-03 76.17023 10.093 9.9989 1.37E-02 4.67E-04 5.26E-03 76.11159 10.091 10.9988 1.51E-02 5.33E-04 6.01E-03 76.05315 10.079 11.9995 1.65E-02 6.42E-04 7.23E-03 75.99864 10.071 12.9984 1.78E-02 1.20E-03 1.36E-02 75.99843 10.053 12.9978 1.78E-02 1.18E-03 1.33E-02 76.02363 10.093 12.4997 1.72E-02 6.59E-04 7.42E-03 76.08185 10.082 11.4996 1.58E-02 5.30E-04 5.97E-03 76.13988 10.073 10.4983 1.44E-02 3.81E-04 4.29E-03 76.19728 10.086 9.4983 1.30E-02 1.73E-04 1.94E-03 76.25489 10.079 8.4991 1.16E-02 9.70E-06 1.09E-04 76.31312 10.079 7.4983 1.03E-02 -8.33E-05 -9.38E-04 76.37176 10.084 6.4976 8.88E-03 -1.18E-04 -1.33E-03 76.43082 10.079 5.4978 7.50E-03 -8.57E-05 -9.65E-04 76.48946 10.082 4.4987 6.14E-03 -8.74E-05 -9.84E-04 76.54768 10.086 3.4974 4.77E-03 -1.42E-04 -1.60E-03 76.60633 10.086 2.4973 3.40E-03 -1.27E-04 -1.43E-03 76.66312 10.091 1.4975 2.04E-03 -3.14E-04 -3.54E-03 76.72093 10.104 0.4989 6.78E-04 -3.64E-04 -4.10E-03 76.74261 10.084 0.0971 1.32E-04 -5.64E-04 -6.35E-03 76.75211 15.263 0.0044 5.87E-06 -9.01E-05 -1.01E-03

249 TABLE D-24 OXYGEN IN [bmim][PF6] (cont.)

25 oC 90 min Sachem SS bucket

Mass Sample Sample Gas Reading Temperature Pressure Density Mole Fraction (mg) (oC) (bar) (g / cm3) of Gas Wt % Gas 76.75748 25.168 0 3.21E-292 1.61E-291 1.81E-290 76.75707 25.077 0.0107 1.38E-05 2.18E-05 2.46E-04 76.75459 25.081 0.0489 6.31E-05 -1.79E-05 -2.01E-04 76.74696 25.075 0.1964 2.53E-04 5.42E-05 6.10E-04 76.72588 25.073 0.598 7.72E-04 2.16E-04 2.43E-03 76.704 25.079 0.9996 1.29E-03 2.86E-04 3.22E-03 76.64948 25.064 1.9993 2.58E-03 4.62E-04 5.20E-03 76.5956 25.079 2.9962 3.87E-03 7.00E-04 7.88E-03 76.54088 25.075 3.9995 5.17E-03 8.91E-04 1.00E-02 76.48739 25.077 4.9967 6.47E-03 1.19E-03 1.34E-02 76.43247 25.073 5.9974 7.77E-03 1.36E-03 1.53E-02 76.37507 25.077 6.9993 9.07E-03 1.26E-03 1.42E-02 76.31786 25.073 7.9977 1.04E-02 1.16E-03 1.31E-02 76.26273 25.07 8.9997 1.17E-02 1.34E-03 1.51E-02 76.20823 25.07 9.9978 1.30E-02 1.57E-03 1.77E-02 76.15102 25.07 10.9981 1.43E-02 1.51E-03 1.70E-02 76.09363 25.077 11.9997 1.56E-02 1.44E-03 1.63E-02 76.03911 25.075 12.9988 1.69E-02 1.70E-03 1.92E-02 76.03911 25.051 12.9979 1.69E-02 1.70E-03 1.92E-02 76.06554 25.07 12.4977 1.63E-02 1.47E-03 1.66E-02 76.12046 25.075 11.4977 1.49E-02 1.25E-03 1.41E-02 76.17436 25.09 10.4983 1.36E-02 9.28E-04 1.05E-02 76.23032 25.068 9.4972 1.23E-02 8.47E-04 9.55E-03 76.2869 25.073 8.4972 1.10E-02 8.47E-04 9.54E-03 76.34347 25.075 7.4972 9.72E-03 8.54E-04 9.62E-03 76.39943 25.079 6.4977 8.42E-03 8.02E-04 9.03E-03 76.45415 25.073 5.4972 7.12E-03 6.09E-04 6.86E-03 76.50907 25.059 4.4965 5.82E-03 4.47E-04 5.04E-03 76.56317 25.081 3.4972 4.52E-03 2.04E-04 2.29E-03 76.61707 25.077 2.4963 3.23E-03 -6.26E-05 -7.05E-04 76.67055 25.077 1.4963 1.93E-03 -3.64E-04 -4.10E-03 76.72443 25.07 0.4973 6.42E-04 -6.04E-04 -6.80E-03 76.7453 25.079 0.0961 1.24E-04 -7.88E-04 -8.86E-03 76.75397 26.04 0.0036 4.63E-06 -3.83E-04 -4.31E-03

250 TABLE D-24 OXYGEN IN [bmim][PF6] (cont.)

50 oC 90 min Sachem SS bucket

Mass Sample Sample Gas Reading Temperature Pressure Density Mole Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 76.74633 50.028 0.0004 1.19E-06 6.09E-06 6.86E-05 76.74551 50.019 0.0108 1.29E-05 -2.91E-05 -3.28E-04 76.74447 50.017 0.0492 5.86E-05 8.43E-05 9.49E-04 76.73827 50.022 0.1976 2.35E-04 2.70E-04 3.04E-03 76.71824 50.017 0.5986 7.13E-04 3.95E-04 4.45E-03 76.69781 50.026 1.0001 1.19E-03 4.76E-04 5.37E-03 76.64887 50.024 1.9999 2.38E-03 9.07E-04 1.02E-02 76.60881 50.01 2.9971 3.57E-03 2.35E-03 2.65E-02 76.57556 50.028 3.9984 4.77E-03 4.60E-03 5.20E-02 76.51486 50.019 4.9975 5.96E-03 3.69E-03 4.17E-02 76.47335 50.019 5.9981 7.16E-03 4.99E-03 5.65E-02 76.42751 50.002 6.9987 8.36E-03 5.81E-03 6.57E-02 76.38002 50.008 7.999 9.56E-03 6.43E-03 7.28E-02 76.33129 50.022 9.0005 1.08E-02 6.92E-03 7.84E-02 76.28028 50.028 9.9993 1.20E-02 7.14E-03 8.09E-02 76.233 50.026 10.9985 1.32E-02 7.79E-03 8.83E-02 76.1851 50.024 11.9987 1.44E-02 8.38E-03 9.51E-02 76.12087 50.019 13.0008 1.56E-02 7.13E-03 8.08E-02 76.1213 50.002 13.0004 1.56E-02 7.18E-03 8.14E-02 76.1469 50.024 12.4982 1.50E-02 7.06E-03 7.99E-02 76.18922 50.013 11.4984 1.38E-02 5.83E-03 6.59E-02 76.25076 50.006 10.4978 1.26E-02 6.79E-03 7.69E-02 76.30465 50.008 9.4992 1.14E-02 6.90E-03 7.81E-02 76.35008 50.01 8.4977 1.02E-02 6.02E-03 6.82E-02 76.39386 50.019 7.4983 8.96E-03 4.98E-03 5.63E-02 76.44155 50.046 6.4977 7.76E-03 4.37E-03 4.94E-02 76.48636 50.017 5.4978 6.56E-03 3.45E-03 3.90E-02 76.53571 50.004 4.4969 5.37E-03 3.05E-03 3.44E-02 76.57762 49.969 3.4982 4.17E-03 1.81E-03 2.04E-02 76.62718 50.022 2.497 2.98E-03 1.43E-03 1.61E-02 76.66827 50.015 1.4972 1.78E-03 8.80E-05 9.91E-04 76.71948 50.026 0.4974 5.92E-04 -7.82E-05 -8.81E-04 76.73993 50.019 0.097 1.16E-04 -1.50E-04 -1.69E-03 76.74696 49.629 0.0044 5.25E-06 9.97E-05 1.12E-03

251 TABLE D-24 OXYGEN IN [bmim][PF6] (cont.)

50 oC 90 min Sachem SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 76.75191 50.002 0.0004 1.19E-06 6.09E-06 6.86E-05 76.7488 50.01 0.0078 9.29E-06 -3.12E-04 -3.52E-03 76.74736 50.017 0.0488 5.81E-05 -2.29E-04 -2.58E-03 76.74033 50.019 0.198 2.36E-04 -1.34E-04 -1.51E-03 76.7201 50.008 0.5986 7.13E-04 -3.52E-05 -3.97E-04 76.69925 50.006 0.9995 1.19E-03 -5.26E-06 -5.93E-05 76.6501 50.024 1.9972 2.38E-03 3.89E-04 4.38E-03 76.60902 50.019 2.9989 3.58E-03 1.74E-03 1.97E-02 76.57475 50.019 3.9974 4.77E-03 3.86E-03 4.36E-02 76.50907 50.026 4.9993 5.97E-03 2.39E-03 2.70E-02 76.4622 50.024 5.9977 7.16E-03 3.07E-03 3.47E-02 76.42174 50.017 6.998 8.36E-03 4.50E-03 5.09E-02 76.37589 50.019 7.9993 9.56E-03 5.32E-03 6.02E-02 76.33192 50.024 8.9989 1.08E-02 6.35E-03 7.19E-02 76.27244 50.037 10.0003 1.20E-02 5.62E-03 6.35E-02 76.22701 49.993 10.9988 1.32E-02 6.49E-03 7.35E-02 76.17705 50.022 11.9991 1.44E-02 6.84E-03 7.75E-02 76.12872 50.002 12.9991 1.56E-02 7.39E-03 8.38E-02 76.12934 49.965 12.999 1.56E-02 7.47E-03 8.47E-02 76.14813 50.019 12.4984 1.50E-02 6.57E-03 7.44E-02 76.20203 50.017 11.4981 1.38E-02 6.66E-03 7.54E-02 76.25076 50.019 10.498 1.26E-02 6.16E-03 6.97E-02 76.28462 50.039 9.499 1.14E-02 3.96E-03 4.48E-02

252 TABLE D-24 OXYGEN IN [bmim][PF6] (cont.)

50 oC 90 min Sachem SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 76.75169 50.035 0 3.21E-292 1.64E-291 1.85E-290 76.74963 50.002 0.0074 8.81E-06 -1.93E-04 -2.18E-03 76.74757 50.017 0.0494 5.88E-05 -1.76E-04 -1.98E-03 76.74055 50.022 0.1976 2.35E-04 -8.59E-05 -9.67E-04 76.72052 50.019 0.5987 7.13E-04 3.93E-05 4.42E-04 76.69987 50.01 0.9994 1.19E-03 9.12E-05 1.03E-03 76.65114 50.017 1.9966 2.38E-03 5.31E-04 5.98E-03 76.6115 50.019 2.9999 3.58E-03 2.06E-03 2.32E-02 76.56958 50.004 3.9978 4.77E-03 3.30E-03 3.72E-02 76.51321 50.031 4.9996 5.97E-03 2.90E-03 3.27E-02 76.47418 50.013 5.9994 7.16E-03 4.48E-03 5.07E-02 76.42131 50.006 6.9997 8.36E-03 4.49E-03 5.08E-02 76.38187 50.013 7.9993 9.56E-03 6.03E-03 6.83E-02 76.32014 50.015 8.9988 1.08E-02 5.03E-03 5.69E-02 76.27947 50.019 9.9984 1.20E-02 6.44E-03 7.29E-02 76.23404 50.015 10.9994 1.32E-02 7.31E-03 8.29E-02 76.17807 50.01 11.9983 1.44E-02 6.98E-03 7.91E-02 76.13265 50.019 12.9995 1.56E-02 7.86E-03 8.92E-02 76.13245 49.984 12.9991 1.56E-02 7.85E-03 8.90E-02 76.15743 50.017 12.498 1.50E-02 7.65E-03 8.67E-02 76.20223 50.039 11.4976 1.38E-02 6.70E-03 7.58E-02

253 TABLE D-25 OXYGEN IN [bmim][Tf2N]

10 oC 90 min Covalent Q4 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 64.05368 14.017 0.022271 2.99E-05 6.50E-05 4.96E-04 64.05405 9.918 0.049337 6.71E-05 2.22E-04 1.69E-03 64.05038 10.115 0.100448 1.37E-04 -3.78E-04 -2.88E-03 64.04676 9.976 0.499853 6.80E-04 6.36E-05 4.85E-04 64.03989 9.995 0.999968 1.36E-03 1.38E-04 1.05E-03 64.02307 10.005 2.499764 3.40E-03 1.13E-03 8.66E-03 64.00252 10.019 3.999011 5.44E-03 1.37E-03 1.04E-02 63.98252 10.014 5.499082 7.48E-03 1.71E-03 1.31E-02 63.96001 9.995 6.997092 9.52E-03 1.54E-03 1.18E-02 63.94136 10.067 8.501833 1.16E-02 2.17E-03 1.66E-02 63.91934 10.173 9.998194 1.36E-02 2.08E-03 1.59E-02 63.90681 10.048 10.9976 1.50E-02 2.49E-03 1.90E-02 63.8911 9.981 12.00374 1.63E-02 2.26E-03 1.73E-02 63.88023 9.933 12.99875 1.77E-02 2.98E-03 2.28E-02 63.88023 9.933 12.99875 1.77E-02 2.98E-03 2.28E-02 63.90289 10 10.98414 1.49E-02 1.65E-03 1.26E-02 63.97195 10.129 5.99851 8.15E-03 1.02E-03 7.80E-03 64.02785 10.125 1.9991 2.72E-03 6.29E-04 4.80E-03 64.05053 10.072 0.19841 2.70E-04 -5.74E-05 -4.38E-04 64.05215 9.995 0.073107 9.94E-05 -9.67E-05 -7.38E-04 64.05161 10.024 0.023645 3.22E-05 -3.54E-04 -2.70E-03

254 TABLE D-25 OXYGEN IN [bmim][Tf2N] (cont.)

25 oC 90 min Covalent Q4 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 64.06034 33.403 0.000562 7.06E-07 1.60E-06 1.22E-05 64.05738 25.014 0.012241 1.58E-05 -5.70E-04 -4.35E-03 64.05707 25.028 0.048376 6.25E-05 -5.28E-04 -4.03E-03 64.05664 25.004 0.099898 1.29E-04 -4.65E-04 -3.55E-03 64.05334 25.004 0.499716 6.45E-04 2.82E-05 2.15E-04 64.04771 25.043 0.999144 1.29E-03 3.35E-04 2.56E-03 64.03288 25.052 2.498116 3.23E-03 1.68E-03 1.28E-02 64.0148 25.038 3.999148 5.16E-03 2.36E-03 1.81E-02 63.99757 24.966 5.498669 7.10E-03 3.22E-03 2.46E-02 63.97831 25.004 7.000114 9.04E-03 3.66E-03 2.80E-02 63.95705 25.043 8.502246 1.10E-02 3.70E-03 2.83E-02 63.93793 25.014 10.00438 1.29E-02 4.17E-03 3.20E-02 63.92775 24.961 10.99801 1.42E-02 4.99E-03 3.83E-02 63.91165 25.019 11.98629 1.55E-02 4.59E-03 3.51E-02 63.8992 25.009 12.98968 1.68E-02 4.97E-03 3.81E-02 63.8992 25.009 12.98968 1.68E-02 4.97E-03 3.81E-02 63.92306 25.014 10.99788 1.42E-02 4.04E-03 3.09E-02 63.98803 24.999 5.998785 7.75E-03 2.73E-03 2.09E-02 64.03239 25.043 1.999649 2.58E-03 1.25E-04 9.51E-04 64.05254 25.004 0.19841 2.56E-04 -1.02E-03 -7.75E-03 64.05405 25.014 0.072832 9.41E-05 -1.08E-03 -8.20E-03 64.05439 25.043 0.021996 2.84E-05 -1.15E-03 -8.80E-03

255 TABLE D-25 OXYGEN IN [bmim][Tf2N] (cont.)

50 oC 90 min Covalent Q4 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 64.05457 49.173 0.021721 2.59E-05 6.25E-05 4.77E-04 64.05444 50.018 0.049475 5.89E-05 1.15E-04 8.81E-04 64.05461 50.013 0.100448 1.20E-04 2.96E-04 2.26E-03 64.05222 50.018 0.499578 5.95E-04 9.53E-04 7.27E-03 64.04739 49.984 0.999556 1.19E-03 1.40E-03 1.07E-02 64.02909 50.023 2.499077 2.98E-03 1.96E-03 1.50E-02 64.01093 50.018 3.998461 4.76E-03 2.54E-03 1.95E-02 64.00455 50.003 5.498532 6.55E-03 5.52E-03 4.23E-02 63.98468 49.955 6.997366 8.34E-03 5.76E-03 4.42E-02 63.97239 49.979 8.495239 1.01E-02 7.52E-03 5.78E-02 63.95394 50.018 9.998194 1.19E-02 8.05E-03 6.19E-02 63.94184 50.057 11.00997 1.31E-02 8.47E-03 6.51E-02 63.93583 50.003 12.00443 1.43E-02 1.01E-02 7.75E-02 63.91682 50.052 12.99806 1.55E-02 9.05E-03 6.96E-02 63.91682 50.052 12.99806 1.55E-02 9.05E-03 6.96E-02 63.9466 49.994 11.01038 1.31E-02 9.43E-03 7.26E-02 63.98744 49.989 5.998785 7.15E-03 3.48E-03 2.66E-02 64.03501 50.008 1.9991 2.38E-03 1.73E-03 1.33E-02 64.05085 49.994 0.19841 2.36E-04 -1.92E-04 -1.46E-03 64.05247 50.008 0.076404 9.10E-05 -2.10E-04 -1.60E-03 64.05334 50.003 0.023919 2.85E-05 -1.83E-04 -1.40E-03

256 TABLE D-26 OXYGEN IN [iBuMeP][TOS]

SS 70 oC 180 min Cytec Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction Wt % (mg) (oC) (bar) (g / cm3) of Gas Gas 69.78371 59.944 0.0002 1.16E-06 1.07E-05 8.81E-05 69.78391 59.931 0.0114 1.32E-05 1.57E-04 1.29E-03 69.78329 59.931 0.0497 5.74E-05 4.59E-04 3.78E-03 69.77504 59.929 0.1974 2.28E-04 6.03E-04 4.97E-03 69.75236 59.929 0.5991 6.92E-04 9.56E-04 7.88E-03 69.72926 59.929 0.9997 1.16E-03 1.22E-03 1.01E-02 69.66947 59.931 2.0006 2.31E-03 1.54E-03 1.27E-02 69.63091 59.933 2.9983 3.47E-03 0.005 0.05 69.56616 59.931 4.0005 4.63E-03 0.005 0.04 69.5041 59.942 5.0008 5.79E-03 0.005 0.04 69.43419 59.94 6.0008 6.95E-03 0.004 0.03 69.3816 59.931 7.0002 8.11E-03 0.005 0.04 69.32923 59.931 7.9983 9.27E-03 0.007 0.06 69.26923 59.935 9.0001 1.04E-02 0.007 0.06 69.2282 59.931 9.9993 1.16E-02 0.011 0.09 69.16674 59.927 10.9995 1.28E-02 0.011 0.09 69.11355 59.933 12 1.39E-02 0.012 0.10 69.05622 59.949 13.0009 1.51E-02 0.013 0.11 69.05622 59.951 13.0023 1.51E-02 0.013 0.11 69.08427 59.929 12.5005 1.45E-02 0.012 0.10 69.13684 59.922 11.4992 1.33E-02 0.011 0.09 69.18118 59.929 10.5011 1.22E-02 0.008 0.07 69.23377 59.929 9.5008 1.10E-02 0.006 0.05 69.28964 59.933 8.5006 9.85E-03 0.005 0.04 69.34532 59.946 7.5004 8.69E-03 0.004 0.03 69.40965 59.949 6.4985 7.52E-03 0.005 0.04 69.46615 59.927 5.4989 6.37E-03 0.004 0.03 69.54389 59.929 4.4996 5.21E-03 0.006 0.05 69.57565 59.935 3.4984 4.05E-03 1.27E-03 1.05E-02 69.64658 59.931 2.4974 2.89E-03 2.88E-03 2.37E-02 69.69379 59.931 1.4975 1.73E-03 3.85E-04 3.17E-03 69.75586 59.931 0.497 5.74E-04 4.73E-04 3.89E-03 69.77937 59.933 0.0957 1.11E-04 2.69E-04 2.21E-03 69.78845 60.067 0.0052 6.01E-06 8.80E-04 7.25E-03

257 TABLE D-27 OXYGEN IN [HeBu3N][Tf2N]

25 oC 90 min Neta Q4 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 77.55282 27.057 0.000837 1.28E-06 6.40E-06 5.23E-05 77.5498 25.134 0.01018 1.31E-05 -4.11E-04 -3.36E-03 77.54843 24.995 0.0492 6.35E-05 -3.75E-04 -3.07E-03 77.5461 25.004 0.100036 1.29E-04 -4.15E-04 -3.39E-03 77.53206 25.019 0.499166 6.45E-04 -5.62E-05 -4.59E-04 77.51414 25.023 0.999007 1.29E-03 3.42E-04 2.79E-03 77.45955 25.014 2.498253 3.23E-03 1.41E-03 1.16E-02 77.40234 25.091 3.998324 5.18E-03 2.09E-03 1.71E-02 77.35095 25.004 5.498807 7.13E-03 3.71E-03 3.05E-02 77.29736 24.999 6.999152 9.08E-03 5.00E-03 4.10E-02 77.24004 25.043 8.498262 1.10E-02 5.70E-03 4.68E-02 77.18586 25.048 9.99902 1.30E-02 6.92E-03 5.69E-02 77.12765 25.038 11.49992 1.50E-02 7.53E-03 6.20E-02 77.12765 25.038 11.49992 1.50E-02 7.53E-03 6.20E-02 77.15676 24.951 10.99925 1.43E-02 8.85E-03 7.30E-02 77.35792 24.995 5.998922 7.78E-03 8.01E-03 6.60E-02 77.50297 24.985 1.999237 2.59E-03 5.01E-03 4.12E-02 77.55922 25.038 0.19841 2.56E-04 2.28E-03 1.87E-02 77.55494 24.956 0.072969 9.43E-05 8.04E-04 6.58E-03 77.55159 25.028 0.023645 3.05E-05 -4.16E-05 -3.40E-04

258 TABLE D-28 OXYGEN IN [MeBu3N][Tf2N]

10 oC 90 min Neta Q1 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 70.33707 10.024 0.011966 1.63E-05 1.19E-04 9.69E-04 70.33553 10.014 0.048925 6.65E-05 2.17E-04 1.77E-03 70.33298 10.01 0.099349 1.35E-04 2.73E-04 2.23E-03 70.31373 10.038 0.499441 6.79E-04 8.90E-04 7.29E-03 70.28597 9.976 0.999694 1.36E-03 1.03E-03 8.40E-03 70.20854 10.01 2.498253 3.40E-03 2.45E-03 2.00E-02 70.12813 9.962 3.999286 5.46E-03 3.41E-03 2.80E-02 70.0485 10.01 5.500043 7.51E-03 4.54E-03 3.72E-02 69.96346 9.995 6.999015 9.57E-03 4.75E-03 3.90E-02 69.87891 10.01 8.498536 1.16E-02 5.09E-03 4.18E-02 69.80288 10.029 9.994485 1.37E-02 6.88E-03 5.66E-02 69.72153 10.014 11.49305 1.58E-02 7.83E-03 6.45E-02 70.27673 9.942 1.164704 1.59E-03 1.06E-03 8.67E-03 70.27483 10.01 1.198641 1.63E-03 1.06E-03 8.70E-03 70.27483 10.01 1.198641 1.63E-03 1.06E-03 8.70E-03 70.32789 9.99 0.198273 2.70E-04 3.68E-04 3.01E-03 70.33372 9.995 0.073381 9.98E-05 1.45E-04 1.18E-03 70.33658 10.019 0.023919 3.25E-05 1.52E-04 1.24E-03

25 oC 90 min Neta Q1 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 70.33394 31.81 0.001112 1.40E-06 1.03E-05 8.46E-05 70.33076 25.019 0.011279 1.46E-05 -4.46E-04 -3.64E-03 70.32899 25.019 0.048101 6.21E-05 -4.03E-04 -3.29E-03 70.32655 25.004 0.100173 1.29E-04 -3.32E-04 -2.71E-03 70.30944 24.995 0.499029 6.45E-04 4.91E-04 4.02E-03 70.28426 25.028 0.999419 1.29E-03 8.79E-04 7.19E-03 70.21378 24.975 2.497704 3.23E-03 2.91E-03 2.39E-02 70.13635 25.028 3.998324 5.18E-03 3.78E-03 3.10E-02 70.06116 25.033 5.498807 7.13E-03 5.06E-03 4.16E-02 69.98651 24.937 6.998877 9.08E-03 6.47E-03 5.33E-02 69.91009 25.009 8.494276 1.10E-02 7.53E-03 6.20E-02 69.83379 25.019 9.998058 1.30E-02 8.72E-03 7.18E-02 69.75701 24.999 11.50074 1.50E-02 9.85E-03 8.13E-02 70.34299 24.84 0.001249 1.61E-06 1.58E-03 1.30E-02

259 TABLE D-28 OXYGEN IN [MeBu3N][Tf2N] (cont.)

50 oC 90 min Neta Q1 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) (g / cm3) Gas Wt % Gas 70.34023 50.173 0.001387 1.65E-06 1.24E-05 1.02E-04 70.3364 51.737 0.010455 1.24E-05 -5.73E-04 -4.68E-03 70.33499 51.261 0.047963 5.69E-05 -4.83E-04 -3.95E-03 70.33291 49.251 0.100448 1.20E-04 -3.70E-04 -3.03E-03 70.31537 49.348 0.499304 5.96E-04 1.63E-04 1.34E-03 70.29205 49.882 0.999281 1.19E-03 5.87E-04 4.80E-03 70.22335 49.911 2.497566 2.98E-03 2.09E-03 1.71E-02 70.13593 49.635 3.998324 4.78E-03 4.18E-04 3.42E-03 70.07238 49.707 5.499082 6.57E-03 2.87E-03 2.35E-02 70.02356 49.809 6.999702 8.37E-03 7.84E-03 6.46E-02 69.94061 49.79 8.492629 1.02E-02 6.91E-03 5.69E-02 69.88554 49.814 9.997646 1.20E-02 1.09E-02 8.97E-02 69.79742 49.829 11.49662 1.38E-02 9.12E-03 7.52E-02 69.79742 49.829 11.49662 1.38E-02 9.12E-03 7.52E-02 69.81619 49.853 10.99348 1.32E-02 7.85E-03 6.47E-02 70.07184 50.334 5.999472 7.16E-03 7.14E-03 5.87E-02 70.26575 50.353 1.999237 2.38E-03 4.94E-03 4.06E-02 70.33508 50.212 0.198135 2.36E-04 8.79E-04 7.19E-03 70.33727 50.232 0.075167 8.95E-05 1.59E-04 1.30E-03 70.33756 50.003 0.025156 3.00E-05 -2.39E-04 -1.95E-03

260 TABLE D-29 OXYGEN IN [MeBuPyrr][Tf2N]

10 oC 90 min Neta Q4 Bucket

Mass Sample Sample Mole Reading Temperature Pressure Gas Density Fraction of Wt % (mg) (oC) (bar) (g / cm3) Gas Gas 79.26698 10.921 0.022683 3.07E-05 1.08E-04 8.81E-04 79.26629 10.264 0.049337 6.70E-05 1.28E-04 1.05E-03 79.26465 10.01 0.100311 1.36E-04 1.19E-04 9.70E-04 79.25352 9.909 0.499029 6.79E-04 3.04E-04 2.48E-03 79.23837 10.038 1.000106 1.36E-03 3.56E-04 2.91E-03 79.19512 9.909 2.498665 3.41E-03 8.51E-04 6.96E-03 79.15054 9.894 3.998324 5.46E-03 1.16E-03 9.51E-03 79.10697 9.899 5.498807 7.51E-03 1.65E-03 1.35E-02 79.06175 9.866 6.997503 9.58E-03 1.89E-03 1.55E-02 79.01638 9.89 8.497438 1.16E-02 2.13E-03 1.75E-02 78.97292 9.923 10.00452 1.37E-02 2.71E-03 2.22E-02 78.94502 9.938 10.99856 1.51E-02 3.22E-03 2.64E-02 78.91232 9.875 11.99701 1.65E-02 3.04E-03 2.49E-02 78.88319 10.029 13.00411 1.79E-02 3.41E-03 2.80E-02 78.88319 10.029 13.00411 1.79E-02 3.41E-03 2.80E-02 78.95185 10.062 10.99774 1.51E-02 4.24E-03 3.48E-02 79.10133 10.11 5.99906 8.20E-03 3.16E-03 2.59E-02 79.21526 10.096 1.999512 2.72E-03 1.56E-03 1.28E-02 79.26406 10.058 0.19841 2.70E-04 4.95E-04 4.05E-03 79.26445 10.048 0.073107 9.94E-05 -4.19E-05 -3.43E-04 79.26516 10.029 0.023507 3.20E-05 -1.69E-04 -1.38E-03

261 TABLE D-29 OXYGEN IN [MeBuPyrr][Tf2N] (cont.)

25 oC 90 min Neta Q4 Bucket

Mass Sample Sample Reading Temperature Pressure Gas Density Mole Fraction (mg) (oC) (bar) (g / cm3) of Gas Wt % Gas 79.27539 31.438 0.000288 1.26E-06 4.55E-06 3.72E-05 79.27174 25.101 0.011416 1.47E-05 -5.10E-04 -4.17E-03 79.2705 24.985 0.049475 6.39E-05 -5.24E-04 -4.29E-03 79.26939 25.023 0.100448 1.30E-04 -4.58E-04 -3.75E-03 79.25963 25.004 0.499441 6.45E-04 -1.07E-04 -8.74E-04 79.24664 25.009 1.000381 1.29E-03 2.22E-04 1.82E-03 79.20895 25.009 2.49839 3.23E-03 1.39E-03 1.14E-02 79.16916 25.028 3.998461 5.18E-03 2.26E-03 1.85E-02 79.12927 25.004 5.499082 7.13E-03 3.12E-03 2.56E-02 79.08759 25.057 7.003412 9.08E-03 3.74E-03 3.07E-02 79.04793 24.985 8.49785 1.10E-02 4.64E-03 3.81E-02 79.00503 24.97 10.00122 1.30E-02 5.10E-03 4.19E-02 78.97977 24.97 10.99636 1.43E-02 5.88E-03 4.84E-02 78.94933 24.956 11.99879 1.56E-02 5.92E-03 4.87E-02 78.92053 24.975 12.9993 1.69E-02 6.20E-03 5.10E-02 78.92053 24.975 12.9993 1.69E-02 6.20E-03 5.10E-02 78.97903 25.014 11.00021 1.43E-02 5.78E-03 4.75E-02 79.11214 25.009 5.999197 7.78E-03 2.83E-03 2.32E-02 79.21842 25.014 1.999512 2.59E-03 5.25E-04 4.30E-03 79.26333 24.961 0.19841 2.56E-04 -9.38E-04 -7.66E-03 79.26558 24.98 0.073107 9.44E-05 -1.17E-03 -9.59E-03 79.26668 24.98 0.02337 3.02E-05 -1.24E-03 -1.01E-02

25 oC 90 min Neta Q4 Bucket

Mass Sample Sample Gas Reading Temperature Pressure Density Mole Fraction (mg) (oC) (bar) (g / cm3) of Gas Wt % Gas 79.31885 32.09 0.000837 1.26E-06 4.55E-06 3.72E-05 79.31528 25.072 0.012378 1.60E-05 -4.93E-04 -4.03E-03 79.31445 24.99 0.049337 6.37E-05 -4.49E-04 -3.67E-03 79.31329 25.019 0.099486 1.28E-04 -3.94E-04 -3.22E-03 79.30387 25.019 0.500403 6.46E-04 2.10E-05 1.71E-04 79.29122 25.033 0.999144 1.29E-03 3.95E-04 3.23E-03 79.27547 33.003 0.0007 1.26E-06 -6.73E-03 -5.47E-02 79.27223 25.076 0.012103 1.56E-05 -7.18E-03 -5.83E-02 79.27126 25.019 0.049063 6.34E-05 -7.16E-03 -5.82E-02 79.26981 25.009 0.099898 1.29E-04 -7.15E-03 -5.81E-02 79.26035 25.004 0.499029 6.45E-04 -6.74E-03 -5.48E-02

262 TABLE D-29 OXYGEN IN [MeBuPyrr][Tf2N] (cont.)

50 oC 90 min Neta Q4 Bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density (g / Fraction of (mg) (oC) (bar) cm3) Gas Wt % Gas 79.26469 47.019 0.024332 2.93E-05 1.10E-04 9.02E-04 79.26431 49.999 0.049475 5.90E-05 1.64E-04 1.34E-03 79.26315 50.003 0.099898 1.19E-04 2.11E-04 1.73E-03 79.25533 50.023 0.500265 5.96E-04 8.02E-04 6.56E-03 79.24426 50.047 0.999144 1.19E-03 1.33E-03 1.09E-02 79.20634 50.033 2.497978 2.98E-03 2.22E-03 1.82E-02 79.17151 49.974 3.997912 4.77E-03 3.59E-03 2.95E-02 79.14341 49.994 5.498257 6.57E-03 6.00E-03 4.93E-02 79.08334 50.091 7.000938 8.36E-03 3.53E-03 2.89E-02 79.06422 50.047 8.501833 1.02E-02 7.32E-03 6.02E-02 79.03222 49.999 9.998194 1.20E-02 9.13E-03 7.53E-02 79.02312 49.955 11.0009 1.32E-02 1.22E-02 1.01E-01 78.97821 50.052 12.00237 1.44E-02 9.85E-03 8.13E-02 78.95515 50.018 13.00218 1.56E-02 1.08E-02 8.93E-02 78.95515 50.018 13.00218 1.56E-02 1.08E-02 8.93E-02 79.0268 49.974 11.00337 1.32E-02 1.28E-02 1.06E-01 79.11512 50.013 5.998235 7.16E-03 3.91E-03 3.21E-02 79.21806 50.013 1.999374 2.38E-03 1.79E-03 1.46E-02 79.25758 50.042 0.19841 2.36E-04 -2.06E-04 -1.69E-03 79.26049 50.033 0.072969 8.69E-05 -3.20E-04 -2.62E-03 79.26195 49.979 0.029415 3.51E-05 -2.91E-04 -2.38E-03

263 TABLE D-30 WATER IN [bmim][PF6]

10 oC 600 min Seddon SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction (mg) (oC) (bar) P / Psat (g / cm3) of Gas Wt % Gas 75.25041 10.008 2.98E-05 2.42E-03 2.28E-08 3.22E-07 2.04E-06 75.29581 10.028 0.001053 8.56E-02 8.05E-07 0.009 0.06 75.32861 10.077 0.001566 1.27E-01 1.20E-06 0.016 0.10 75.36079 10.084 0.002055 1.67E-01 1.57E-06 0.023 0.15 75.39504 10.082 0.002567 2.09E-01 1.96E-06 0.029 0.19 75.4297 10.079 0.003056 2.48E-01 2.34E-06 0.036 0.24 75.46663 10.095 0.003568 2.90E-01 2.73E-06 0.043 0.29 75.50398 10.093 0.004057 3.30E-01 3.10E-06 0.051 0.34 75.54462 10.088 0.004569 3.71E-01 3.49E-06 0.058 0.39 75.58465 10.082 0.005057 4.11E-01 3.87E-06 0.066 0.44 75.62756 10.073 0.00557 4.53E-01 4.26E-06 0.073 0.50 75.71215 10.079 0.006571 5.34E-01 5.03E-06 0.088 0.61 75.81056 10.088 0.007573 6.16E-01 5.79E-06 0.105 0.74 75.91847 10.082 0.008573 6.97E-01 6.56E-06 0.123 0.88 76.03853 10.086 0.009574 7.78E-01 7.32E-06 0.142 1.04 76.03853 10.086 0.009574 7.78E-01 7.32E-06 0.142 1.04 75.95498 10.115 0.008574 6.97E-01 6.56E-06 0.129 0.93 75.85657 10.084 0.007574 6.16E-01 5.79E-06 0.113 0.80 75.75877 10.086 0.00657 5.34E-01 5.02E-06 0.096 0.67 75.66779 10.079 0.005572 4.53E-01 4.26E-06 0.080 0.55 75.61683 10.084 0.005058 4.11E-01 3.87E-06 0.071 0.48 75.57516 10.097 0.00457 3.72E-01 3.49E-06 0.064 0.43 75.5341 10.086 0.004058 3.30E-01 3.10E-06 0.056 0.38 75.49614 10.079 0.003566 2.90E-01 2.73E-06 0.049 0.33 75.45838 10.086 0.003054 2.48E-01 2.34E-06 0.042 0.28 75.4231 10.077 0.002568 2.09E-01 1.96E-06 0.035 0.23 75.38761 10.077 0.002055 1.67E-01 1.57E-06 0.028 0.18 75.3544 10.079 0.001567 1.27E-01 1.20E-06 0.021 0.14 75.32119 10.079 0.001054 8.57E-02 8.06E-07 0.015 0.09 75.2663 10.142 5.93E-05 4.82E-03 4.53E-08 0.003 0.02

264 TABLE D-30 WATER IN [bmim][PF6] (cont.)

25 oC 60 min Seddon SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction (mg) (oC) (bar) P / Psat (g / cm3) of Gas Wt % Gas 75.26238 25.035 5.2E-06 1.66E-04 3.78E-09 5.34E-08 3.39E-07 75.28136 25 0.000984 3.14E-02 7.15E-07 0.004 0.03 75.29684 25.075 0.001497 4.78E-02 1.09E-06 0.007 0.05 75.3119 25.073 0.001984 6.34E-02 1.44E-06 0.010 0.07 75.34264 25.077 0.002986 9.54E-02 2.17E-06 0.017 0.11 75.37565 25.079 0.003988 1.27E-01 2.90E-06 0.023 0.15 75.4101 25.081 0.004989 1.59E-01 3.62E-06 0.030 0.20 75.47881 25.081 0.00699 2.23E-01 5.08E-06 0.043 0.29 75.55514 25.068 0.008992 2.87E-01 6.53E-06 0.058 0.39 75.63561 25.073 0.010995 3.51E-01 7.99E-06 0.073 0.49 75.81015 25.07 0.014998 4.79E-01 1.09E-05 0.103 0.72 76.07463 25.075 0.020003 6.39E-01 1.45E-05 0.146 1.07 76.41052 25.075 0.025007 7.99E-01 1.82E-05 0.194 1.50 76.41073 25.086 0.025006 7.99E-01 1.82E-05 0.194 1.50 76.10847 25.079 0.020003 6.39E-01 1.45E-05 0.151 1.11 75.84007 25.068 0.014999 4.79E-01 1.09E-05 0.108 0.76 75.65871 25.086 0.010995 3.51E-01 7.99E-06 0.077 0.52 75.57516 25.073 0.008993 2.87E-01 6.53E-06 0.062 0.41 75.43176 25.068 0.004989 1.59E-01 3.62E-06 0.034 0.22 75.36079 25.068 0.002987 9.54E-02 2.17E-06 0.020 0.13 75.31128 25.073 0.001498 4.79E-02 1.09E-06 0.010 0.07 75.26858 25.373 0.000169 5.38E-03 1.22E-07 1.30E-03 8.25E-03

265 TABLE D-30 WATER IN [bmim][PF6] (cont.)

25 oC 60 min Seddon SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) P / Psat (g / cm3) Gas Wt % Gas 76.81402 27.202 8.6E-06 2.75E-04 6.20E-09 8.59E-08 5.45E-07 77.29546 25.099 0.015004 4.79E-01 1.09E-05 0.090 0.62 77.56958 25.081 0.02001 6.39E-01 1.45E-05 0.134 0.98 77.761 25.075 0.022989 7.34E-01 1.67E-05 0.163 1.22 77.90559 25.07 0.024991 7.98E-01 1.82E-05 0.183 1.40 77.98789 25.077 0.025992 8.30E-01 1.89E-05 0.194 1.51 78.07143 25.079 0.026993 8.62E-01 1.96E-05 0.205 1.61 78.1593 25.077 0.027994 8.94E-01 2.03E-05 0.217 1.72 78.25378 25.075 0.028995 9.26E-01 2.11E-05 0.228 1.84 78.25378 25.07 0.028997 9.26E-01 2.11E-05 0.228 1.84 78.18365 25.07 0.027994 8.94E-01 2.03E-05 0.220 1.75 78.10341 25.075 0.026996 8.62E-01 1.96E-05 0.209 1.65 78.02461 25.079 0.025992 8.30E-01 1.89E-05 0.199 1.55 77.94974 25.075 0.024992 7.98E-01 1.82E-05 0.189 1.46 77.81814 25.059 0.022994 7.35E-01 1.67E-05 0.171 1.29 77.64034 25.068 0.020011 6.39E-01 1.45E-05 0.145 1.07 76.80556 25.15 7.3E-06 2.33E-04 5.30E-09 -0.002 -0.01 77.15498 25.066 0.01 3.19E-01 7.26E-06 0.066 0.44 77.65538 25.073 0.019985 6.39E-01 1.45E-05 0.147 1.08 77.65538 25.101 0.019984 6.38E-01 1.45E-05 0.147 1.08 77.1655 25.075 0.010008 3.20E-01 7.27E-06 0.067 0.46 76.81133 25.652 0.000104 3.31E-03 7.50E-08 -5.52E-04 -3.50E-03

266 TABLE D-30 WATER IN [bmim][PF6] (cont.)

25 oC 120 min Seddon SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) P / Psat (g / cm3) Gas Wt % Gas 82.86466 26.877 6.2E-06 1.98E-04 4.48E-09 6.29E-08 3.99E-07 82.86446 25.064 0.000056 1.79E-03 4.07E-08 -3.75E-05 -2.38E-04 82.88551 25.073 0.001009 3.22E-02 7.33E-07 0.004 0.03 82.90038 25.079 0.001498 4.79E-02 1.09E-06 0.007 0.04 82.92227 25.066 0.002009 6.42E-02 1.46E-06 0.011 0.07 82.9582 25.073 0.00301 9.62E-02 2.19E-06 0.018 0.11 83.02943 25.075 0.004989 1.59E-01 3.62E-06 0.030 0.20 83.24419 25.073 0.009992 3.19E-01 7.26E-06 0.067 0.46 83.49425 25.077 0.014998 4.79E-01 1.09E-05 0.107 0.76 83.79405 25.077 0.020002 6.39E-01 1.45E-05 0.150 1.11 84.59812 25.066 0.02901 9.27E-01 2.11E-05 0.248 2.05 84.59812 25.051 0.029007 9.27E-01 2.11E-05 0.248 2.05 84.21736 25.066 0.025005 7.99E-01 1.82E-05 0.205 1.61 83.42921 25.075 0.013001 4.15E-01 9.44E-06 0.097 0.68 83.15002 25.07 0.006994 2.23E-01 5.08E-06 0.052 0.34 82.96914 25.07 0.0025 7.99E-02 1.82E-06 0.020 0.13 82.89294 25.075 0.000499 1.60E-02 3.63E-07 0.005 0.03 82.87561 25.287 6.99E-05 2.23E-03 5.07E-08 2.08E-03 1.32E-02

267 TABLE D-30 WATER IN [bmim][PF6] (cont.)

35 oC 60 min Seddon SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) P / Psat (g / cm3) Gas Wt % Gas 75.17615 33.452 1.22E-05 2.20E-04 8.62E-09 1.22E-07 7.74E-07 75.18687 34.913 0.000974 1.76E-02 6.85E-07 2.25E-03 1.43E-02 75.19512 34.922 0.001486 2.68E-02 1.04E-06 0.004 0.03 75.204 34.898 0.001974 3.56E-02 1.39E-06 0.006 0.04 75.22215 34.911 0.002976 5.37E-02 2.09E-06 0.010 0.06 75.24175 34.916 0.003977 7.18E-02 2.80E-06 0.014 0.09 75.26197 34.918 0.004976 8.98E-02 3.50E-06 0.018 0.11 75.30468 34.909 0.006977 1.26E-01 4.91E-06 0.026 0.17 75.35006 34.913 0.008981 1.62E-01 6.31E-06 0.035 0.23 75.39896 34.911 0.010983 1.98E-01 7.72E-06 0.045 0.30 75.49964 34.913 0.014987 2.71E-01 1.05E-05 0.064 0.43 75.63953 34.913 0.019991 3.61E-01 1.41E-05 0.089 0.61 75.79385 34.911 0.024997 4.51E-01 1.76E-05 0.115 0.82 75.9655 34.909 0.029952 5.41E-01 2.11E-05 0.142 1.04 76.3837 34.918 0.039963 7.21E-01 2.81E-05 0.202 1.58 76.3839 34.913 0.039961 7.21E-01 2.81E-05 0.202 1.58 75.9915 34.909 0.029953 5.41E-01 2.11E-05 0.146 1.07 75.82211 34.909 0.02498 4.51E-01 1.76E-05 0.120 0.85 75.6715 34.909 0.019975 3.61E-01 1.40E-05 0.094 0.66 75.53534 34.918 0.014966 2.70E-01 1.05E-05 0.070 0.48 75.43341 34.918 0.01096 1.98E-01 7.71E-06 0.051 0.34 75.38432 34.913 0.008958 1.62E-01 6.30E-06 0.042 0.28 75.33789 34.909 0.006955 1.26E-01 4.89E-06 0.033 0.22 75.29312 34.913 0.004954 8.94E-02 3.48E-06 0.024 0.16 75.27063 34.916 0.003953 7.14E-02 2.78E-06 0.019 0.13 75.25021 34.913 0.002977 5.37E-02 2.09E-06 0.015 0.10 75.22916 34.911 0.001975 3.57E-02 1.39E-06 0.011 0.07 75.21844 34.911 0.001461 2.64E-02 1.03E-06 0.009 0.06 75.20833 34.909 0.000975 1.76E-02 6.85E-07 0.007 0.04 75.19182 34.971 0.000127 2.29E-03 8.91E-08 0.003 0.02

268 TABLE D-30 WATER IN [bmim][PF6] (cont.)

50 oC 45 min Seddon SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) P / Psat (g / cm3) Gas Wt % Gas -3.35E- 75.1712 49.954 -0.00005 -4.11E-04 08 -4.74E-07 -3.01E-06 75.17387 49.921 0.000919 7.56E-03 6.16E-07 5.69E-04 3.61E-03 75.17903 50.019 0.001433 1.18E-02 9.60E-07 1.65E-03 1.05E-02 75.18419 50.019 0.00192 1.58E-02 1.29E-06 0.003 0.02 75.19492 50.013 0.002922 2.40E-02 1.96E-06 0.005 0.03 75.20668 50.024 0.003923 3.23E-02 2.63E-06 0.007 0.05 75.21885 50.013 0.004924 4.05E-02 3.30E-06 0.010 0.06 75.24278 50.019 0.006926 5.70E-02 4.64E-06 0.015 0.10 75.26878 50.019 0.008928 7.34E-02 5.98E-06 0.020 0.13 75.29601 50.019 0.01093 8.99E-02 7.33E-06 0.026 0.17 75.34718 50.019 0.014934 1.23E-01 1.00E-05 0.036 0.23 75.41589 50.019 0.019939 1.64E-01 1.34E-05 0.049 0.33 75.48706 50.013 0.024944 2.05E-01 1.67E-05 0.062 0.42 75.56236 50.017 0.029924 2.46E-01 2.01E-05 0.076 0.52 75.71916 50.017 0.039933 3.28E-01 2.68E-05 0.103 0.73

50 oC 45 min Seddon SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) P / Psat (g / cm3) Gas Wt % Gas 75.24876 49.89 0.000081 6.66E-04 5.43E-08 7.68E-07 4.87E-06 75.24753 49.357 -0.00009 -7.40E-04 -6.04E-08 -2.59E-04 -1.64E-03 75.24753 49.418 -0.00014 -1.15E-03 -9.40E-08 -2.59E-04 -1.64E-03 75.25248 50.061 0.000842 6.93E-03 5.64E-07 7.87E-04 4.99E-03 75.25743 50.028 0.001356 1.11E-02 9.09E-07 1.83E-03 1.16E-02 75.26238 50.015 0.001845 1.52E-02 1.24E-06 2.86E-03 1.82E-02 75.2729 50.019 0.002845 2.34E-02 1.91E-06 0.005 0.0322 75.28426 50.024 0.003846 3.16E-02 2.58E-06 0.007 0.0474 75.29601 50.017 0.004847 3.99E-02 3.25E-06 0.010 0.0630 75.31953 50.022 0.006849 5.63E-02 4.59E-06 0.015 0.0944 75.34387 50.01 0.008851 7.28E-02 5.93E-06 0.020 0.1268 75.36905 50.002 0.010853 8.92E-02 7.27E-06 0.025 0.1603 75.42124 50.019 0.014856 1.22E-01 9.96E-06 0.035 0.2296 75.48768 50.022 0.019857 1.63E-01 1.33E-05 0.048 0.3177 75.55989 50.01 0.024866 2.04E-01 1.67E-05 0.061 0.4132 75.63251 50.022 0.029845 2.45E-01 2.00E-05 0.075 0.5092 75.79323 50.019 0.039852 3.28E-01 2.67E-05 0.103 0.7207 75.97272 50.017 0.049863 4.10E-01 3.34E-05 0.132 0.9559

269 TABLE D-31 WATER IN [C8mim][BF4]

10 oC 180 min Seddon SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction (mg) (oC) (bar) P / Psat (g / cm3) of Gas Wt % Gas 77.21824 16.16 2.4E-06 1.95E-04 1.80E-09 3.06E-08 1.95E-07 77.26176 10.086 0.000466 3.79E-02 3.56E-07 0.009 0.06 77.33147 10.084 0.000981 7.97E-02 7.50E-07 0.022 0.15 77.41069 10.082 0.001493 1.21E-01 1.14E-06 0.038 0.25 77.49423 10.084 0.001982 1.61E-01 1.52E-06 0.053 0.36 77.58498 10.086 0.002495 2.03E-01 1.91E-06 0.069 0.47 77.98206 10.082 0.004497 3.66E-01 3.44E-06 0.134 0.98 78.53382 10.086 0.006498 5.28E-01 4.97E-06 0.211 1.68 79.80568 10.086 0.009501 7.72E-01 7.27E-06 0.344 3.24 79.80589 10.071 0.009497 7.72E-01 7.26E-06 0.344 3.24 78.7764 10.079 0.006475 5.26E-01 4.95E-06 0.240 1.98 78.20854 10.079 0.004473 3.64E-01 3.42E-06 0.167 1.27 77.76403 10.084 0.002495 2.03E-01 1.91E-06 0.100 0.70 77.45813 10.079 0.000982 7.98E-02 7.51E-07 0.046 0.31 77.27166 12.416 5.37E-05 4.37E-03 4.07E-08 0.011 0.07

25 oC 120 min Seddon SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction (mg) (oC) (bar) P / Psat (g / cm3) of Gas Wt % Gas 77.24011 25.674 6.8E-06 2.17E-04 4.93E-09 8.39E-08 5.36E-07 77.28919 25.077 0.000961 3.07E-02 6.98E-07 0.010 0.06 77.329 25.079 0.0015 4.79E-02 1.09E-06 0.018 0.12 77.36552 25.077 0.001964 6.27E-02 1.43E-06 0.025 0.16 77.4439 25.077 0.002966 9.48E-02 2.15E-06 0.040 0.26 77.53033 25.073 0.003967 1.27E-01 2.88E-06 0.056 0.37 77.6219 25.077 0.004967 1.59E-01 3.61E-06 0.072 0.49 77.81002 25.077 0.006971 2.23E-01 5.06E-06 0.104 0.73 78.4212 25.073 0.012487 3.99E-01 9.07E-06 0.193 1.51 79.64232 25.073 0.019983 6.38E-01 1.45E-05 0.328 3.02 81.04022 25.066 0.024987 7.98E-01 1.81E-05 0.435 4.69 81.04041 25.07 0.024988 7.98E-01 1.81E-05 0.435 4.69 78.6023 25.084 0.012489 3.99E-01 9.07E-06 0.216 1.73 77.93565 25.075 0.00697 2.23E-01 5.06E-06 0.124 0.89 77.62644 25.07 0.003968 1.27E-01 2.88E-06 0.073 0.50 77.43791 25.077 0.001966 6.28E-02 1.43E-06 0.039 0.26 77.342 25.073 0.000963 3.08E-02 7.00E-07 0.020 0.13 77.26444 25.276 0.000102 3.25E-03 7.38E-08 0.005 0.03

270 TABLE D-31 WATER IN [C8mim][BF4] (cont.)

25 oC 180 min Seddon SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction (mg) (oC) (bar) P / Psat (g / cm3) of Gas Wt % Gas 77.2104 28.008 1.09E-05 3.48E-04 7.84E-09 1.33E-07 8.52E-07 77.27022 25.084 0.000974 3.11E-02 7.07E-07 0.012 0.08 77.31291 25.077 0.001511 4.83E-02 1.10E-06 0.020 0.13 77.35108 25.073 0.001975 6.31E-02 1.43E-06 0.028 0.18 77.43276 25.073 0.002974 9.50E-02 2.16E-06 0.043 0.29 77.52062 25.075 0.003978 1.27E-01 2.89E-06 0.059 0.40 77.6116 25.079 0.004978 1.59E-01 3.62E-06 0.075 0.52 77.80383 25.07 0.006978 2.23E-01 5.07E-06 0.107 0.76 78.42904 25.079 0.012498 3.99E-01 9.08E-06 0.198 1.55 79.67717 25.073 0.019992 6.39E-01 1.45E-05 0.334 3.10 81.11549 25.075 0.024997 7.99E-01 1.82E-05 0.442 4.82 81.1157 25.055 0.024992 7.98E-01 1.82E-05 0.442 4.82 78.53135 25.077 0.012499 3.99E-01 9.08E-06 0.211 1.68 77.88305 25.077 0.006981 2.23E-01 5.07E-06 0.120 0.86 77.58189 25.073 0.003979 1.27E-01 2.89E-06 0.070 0.48 77.39625 25.07 0.001977 6.32E-02 1.44E-06 0.036 0.24 77.30446 25.068 0.000975 3.12E-02 7.08E-07 0.019 0.12 77.22814 25.221 0.000104 3.31E-03 7.53E-08 0.004 0.02

271 TABLE D-31 WATER IN [C8mim][BF4] (cont.)

25 oC 300 min Seddon SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction (mg) (oC) (bar) P / Psat (g / cm3) of Gas Wt % Gas 77.17162 25.068 3.2E-06 1.02E-04 2.32E-09 3.96E-08 2.53E-07 77.25063 25.075 0.000949 3.03E-02 6.89E-07 0.016 0.10 77.29662 25.081 0.001489 4.76E-02 1.08E-06 0.025 0.16 77.33478 25.079 0.001949 6.23E-02 1.42E-06 0.032 0.21 77.41832 25.077 0.002947 9.42E-02 2.14E-06 0.048 0.32 77.50475 25.077 0.00395 1.26E-01 2.87E-06 0.063 0.43 77.59551 25.075 0.004951 1.58E-01 3.60E-06 0.079 0.55 77.78734 25.075 0.006953 2.22E-01 5.05E-06 0.111 0.79 78.42512 25.062 0.012471 3.98E-01 9.06E-06 0.203 1.60 79.69017 25.079 0.019964 6.38E-01 1.45E-05 0.338 3.16 81.14314 25.077 0.024969 7.98E-01 1.81E-05 0.446 4.90 82.06248 25.075 0.026972 8.62E-01 1.96E-05 0.498 5.96 83.42756 25.07 0.028973 9.26E-01 2.10E-05 0.559 7.50 83.42756 25.066 0.028971 9.26E-01 2.10E-05 0.559 7.50 82.08621 25.073 0.026972 8.62E-01 1.96E-05 0.499 5.99 81.18646 25.077 0.024973 7.98E-01 1.81E-05 0.449 4.95 78.49917 25.07 0.012473 3.98E-01 9.06E-06 0.212 1.69 77.84612 25.081 0.006955 2.22E-01 5.05E-06 0.120 0.87 77.54414 25.07 0.003953 1.26E-01 2.87E-06 0.070 0.48 77.35623 25.075 0.001951 6.23E-02 1.42E-06 0.036 0.24 77.26547 25.073 0.000949 3.03E-02 6.89E-07 0.019 0.12 77.18502 25.17 6.33E-05 2.02E-03 4.60E-08 2.71E-03 1.74E-02

272 TABLE D-31 WATER IN [C8mim][BF4] (cont.)

Seddon - 25 oC 180 min cleaned SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction (mg) (oC) (bar) P / Psat (g / cm3) of Gas Wt % Gas 75.81233 25.112 7.2E-06 2.30E-04 5.23E-09 8.92E-08 5.70E-07 75.81233 25.081 0.000047 1.50E-03 3.41E-08 5.83E-07 3.72E-06 75.83485 25.079 0.000999 3.19E-02 7.26E-07 0.005 0.03 75.86375 25.068 0.001485 4.75E-02 1.08E-06 0.011 0.07 75.8877 25.081 0.002 6.39E-02 1.45E-06 0.015 0.10 75.95481 25.073 0.002998 9.58E-02 2.18E-06 0.029 0.19 76.10266 25.079 0.004977 1.59E-01 3.61E-06 0.057 0.38 76.5621 25.081 0.009983 3.19E-01 7.25E-06 0.134 0.98 77.14273 25.081 0.014989 4.79E-01 1.09E-05 0.216 1.73 77.92593 25.068 0.019994 6.39E-01 1.45E-05 0.304 2.71 80.78539 25.066 0.028998 9.26E-01 2.11E-05 0.507 6.16 80.78579 25.073 0.028997 9.26E-01 2.11E-05 0.507 6.16 79.26687 25.077 0.024999 7.99E-01 1.82E-05 0.417 4.36 77.08408 25.081 0.012988 4.15E-01 9.43E-06 0.208 1.65 76.44522 25.068 0.006982 2.23E-01 5.07E-06 0.116 0.83 76.05166 25.075 0.00249 7.96E-02 1.81E-06 0.047 0.31 75.88481 25.077 0.000487 1.56E-02 3.54E-07 0.015 0.10 75.8427 25.223 0.000057 1.82E-03 4.14E-08 0.006 0.04

35 oC 150 min Seddon SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction (mg) (oC) (bar) P / Psat (g / cm3) of Gas Wt % Gas 77.19513 37.272 9.7E-06 1.75E-04 6.77E-09 1.15E-07 7.36E-07 77.22669 34.913 0.001 1.80E-02 7.03E-07 0.006 0.04 77.24979 34.909 0.001513 2.73E-02 1.06E-06 0.011 0.07 77.27208 34.913 0.002 3.61E-02 1.41E-06 0.015 0.10 77.32055 34.913 0.003001 5.42E-02 2.11E-06 0.025 0.16 77.37211 34.911 0.004003 7.22E-02 2.81E-06 0.035 0.23 77.42574 34.913 0.005001 9.03E-02 3.52E-06 0.045 0.30 77.53775 34.916 0.007005 1.26E-01 4.93E-06 0.065 0.44 77.87624 34.909 0.012523 2.26E-01 8.81E-06 0.122 0.88 78.41296 34.913 0.020017 3.61E-01 1.41E-05 0.198 1.55 79.34178 34.913 0.030004 5.42E-01 2.11E-05 0.304 2.71

273 TABLE D-31 WATER IN [C8mim][BF4] (cont.)

35 oC 150 min Seddon SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction (mg) (oC) (bar) P / Psat (g / cm3) of Gas Wt % Gas 77.20731 35.11 6.5E-06 1.17E-04 4.57E-09 7.77E-08 4.96E-07 77.22484 34.925 0.000801 1.45E-02 5.63E-07 0.004 0.02 77.24237 34.92 0.001317 2.38E-02 9.26E-07 0.007 0.05 77.26052 34.918 0.001805 3.26E-02 1.27E-06 0.011 0.07 77.30239 34.898 0.002806 5.07E-02 1.97E-06 0.019 0.12 77.34839 34.913 0.003804 6.87E-02 2.67E-06 0.028 0.18 77.39893 34.913 0.004809 8.68E-02 3.38E-06 0.037 0.25 77.50805 34.913 0.006808 1.23E-01 4.79E-06 0.058 0.39 77.84571 34.909 0.012304 2.22E-01 8.65E-06 0.115 0.82 78.38036 34.911 0.019823 3.58E-01 1.39E-05 0.192 1.50 79.29249 34.918 0.029782 5.38E-01 2.09E-05 0.297 2.63 80.67552 34.911 0.039795 7.18E-01 2.80E-05 0.413 4.30 81.77782 34.913 0.044797 8.09E-01 3.15E-05 0.481 5.59 84.09918 34.874 0.051593 9.31E-01 3.63E-05 0.583 8.20

TABLE D-32 WATER IN [C8mim][PF6]

10 oC 180 min Seddon SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction (mg) (oC) (bar) P / Psat (g / cm3) of Gas Wt % Gas 87.661 14.066 1.2E-06 9.76E-05 9.05E-10 1.65E-08 8.75E-08 87.67441 10.084 0.000466 3.79E-02 3.56E-07 2.89E-03 1.53E-02 87.69483 10.084 0.000981 7.98E-02 7.50E-07 0.007 0.04 87.71813 10.084 0.001493 1.21E-01 1.14E-06 0.012 0.07 87.74124 10.077 0.001983 1.61E-01 1.52E-06 0.017 0.09 87.7664 10.086 0.002492 2.03E-01 1.91E-06 0.022 0.12 87.86953 10.082 0.004497 3.66E-01 3.44E-06 0.043 0.24 87.99516 10.084 0.006499 5.28E-01 4.97E-06 0.067 0.38 88.21793 10.075 0.009501 7.72E-01 7.27E-06 0.107 0.63 88.21793 10.069 0.009498 7.72E-01 7.26E-06 0.107 0.63 88.03539 10.086 0.006475 5.26E-01 4.95E-06 0.075 0.43 87.9077 10.082 0.004473 3.64E-01 3.42E-06 0.051 0.28 87.79652 10.079 0.002496 2.03E-01 1.91E-06 0.028 0.15 87.7171 10.079 0.000982 7.98E-02 7.51E-07 0.012 0.06 87.6709 12.902 8.25E-05 6.71E-03 6.25E-08 2.13E-03 1.13E-02

274 TABLE D-32 WATER IN [C8mim][PF6] (cont.)

25 oC 180 min Seddon SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction (mg) (oC) (bar) P / Psat (g / cm3) of Gas Wt % Gas 87.66554 29.937 1.12E-05 3.58E-04 8.00E-09 1.46E-07 7.74E-07 87.68039 25.075 0.000999 3.19E-02 7.25E-07 3.20E-03 1.70E-02 87.69173 25.077 0.001514 4.84E-02 1.10E-06 0.006 0.03 87.70349 25.075 0.002002 6.40E-02 1.45E-06 0.008 0.04 87.72762 25.077 0.003003 9.59E-02 2.18E-06 0.013 0.07 87.7532 25.075 0.004002 1.28E-01 2.91E-06 0.019 0.10 87.78001 25.077 0.005001 1.60E-01 3.63E-06 0.024 0.13 87.8355 25.079 0.007007 2.24E-01 5.09E-06 0.035 0.19 88.00609 25.077 0.012524 4.00E-01 9.10E-06 0.068 0.39 88.28868 25.077 0.020018 6.40E-01 1.45E-05 0.119 0.71 88.52258 25.073 0.025024 8.00E-01 1.82E-05 0.156 0.97 88.52279 25.048 0.025021 7.99E-01 1.82E-05 0.156 0.97 88.03042 25.075 0.012526 4.00E-01 9.10E-06 0.073 0.42 87.85593 25.073 0.007008 2.24E-01 5.09E-06 0.039 0.22 87.76991 25.077 0.004005 1.28E-01 2.91E-06 0.022 0.12 87.71608 25.077 0.002003 6.40E-02 1.45E-06 0.011 0.06 87.69008 25.077 0.001002 3.20E-02 7.28E-07 0.005 0.03 87.66657 25.09 3.27E-05 1.04E-03 2.37E-08 2.22E-04 1.18E-03

275 TABLE D-32 WATER IN [C8mim][PF6] (cont.)

25 oC 180 min Sachem SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction (mg) (oC) (bar) P / Psat (g / cm3) of Gas Wt % Gas 73.46291 26.012 5.6E-06 1.79E-04 4.05E-09 7.62E-08 4.04E-07 73.46829 25.068 0.00005 1.60E-03 3.63E-08 1.38E-03 7.33E-03 73.47118 25.081 0.001003 3.21E-02 7.29E-07 2.14E-03 1.13E-02 73.4753 25.075 0.001492 4.77E-02 1.08E-06 0.0032 0.02 73.48357 25.073 0.002003 6.40E-02 1.46E-06 0.0053 0.03 73.49513 25.07 0.003005 9.60E-02 2.18E-06 0.0083 0.04 73.53105 25.077 0.004982 1.59E-01 3.62E-06 0.0173 0.09 73.65619 25.077 0.009986 3.19E-01 7.25E-06 0.0475 0.26 73.80155 25.081 0.01499 4.79E-01 1.09E-05 0.0803 0.46 73.96716 25.079 0.019996 6.39E-01 1.45E-05 0.1150 0.68 74.34834 25.077 0.029003 9.27E-01 2.11E-05 0.1857 1.19 74.34854 25.064 0.029001 9.27E-01 2.11E-05 0.1857 1.19 74.2007 25.07 0.025001 7.99E-01 1.82E-05 0.1597 1.00 73.81828 25.075 0.012996 4.15E-01 9.44E-06 0.0839 0.48 73.66074 25.075 0.006986 2.23E-01 5.07E-06 0.0485 0.27 73.55357 25.077 0.002495 7.97E-02 1.81E-06 0.0228 0.12 73.50422 25.075 0.000491 1.57E-02 3.57E-07 0.0105 0.06

276 TABLE D-32 WATER IN [C8mim][PF6] (cont.)

35 oC 150 min Seddon SS bucket

Mass Sample Sample Gas Mole Reading Temperature Pressure Density Fraction of (mg) (oC) (bar) P / Psat (g / cm3) Gas Wt % Gas 87.66142 37.109 9.7E-06 1.75E-04 6.77E-09 1.24E-07 6.55E-07 87.66842 34.92 0.000973 1.76E-02 6.84E-07 1.52E-03 8.05E-03 87.67565 34.918 0.001488 2.69E-02 1.05E-06 0.003 1.63E-02 87.68287 34.916 0.001976 3.57E-02 1.39E-06 0.005 0.02 87.69833 34.909 0.002975 5.37E-02 2.09E-06 0.008 0.04 87.71462 34.911 0.003979 7.18E-02 2.80E-06 0.011 0.06 87.73237 34.911 0.004979 8.99E-02 3.50E-06 0.015 0.08 87.76804 34.911 0.00698 1.26E-01 4.91E-06 0.023 0.12 87.87408 34.918 0.012499 2.26E-01 8.79E-06 0.044 0.24 88.03373 34.916 0.019993 3.61E-01 1.41E-05 0.074 0.42 88.27774 34.92 0.029979 5.41E-01 2.11E-05 0.118 0.70 88.57869 34.916 0.039989 7.22E-01 2.81E-05 0.165 1.04 88.57869 34.929 0.039993 7.22E-01 2.81E-05 0.165 1.04 88.29424 34.913 0.030005 5.42E-01 2.11E-05 0.120 0.72 87.89017 34.907 0.012499 2.26E-01 8.79E-06 0.047 0.26 87.78022 34.911 0.007007 1.26E-01 4.93E-06 0.025 0.14 87.72432 34.9 0.004004 7.23E-02 2.82E-06 0.013 0.07 87.68803 34.911 0.002002 3.61E-02 1.41E-06 0.006 0.03 87.6709 34.913 0.001001 1.81E-02 7.04E-07 2.05E-03 1.09E-02 87.65482 34.971 0.000104 1.87E-03 7.29E-08 -1.42E-03 -7.52E-03

277

APPENDIX E

FLOWING VERSUS STATIC MODES ON THE GRAVIMETRIC

MICROBALANCE

The gravimetric microbalance can be used in a static gas mode or flowing gas

mode (where the gas flows continuously past the sample). Both modes were used to

o measure the solubility of CO2 in [emim][Tf2N] at 25 C. As can be seen in the figure

below, there was no noticeable difference between the two modes.

14 Static Mode 12 Flowing Mode

10

8

6 Pressure (bar) 4

2

0 0.00 0.05 0.10 0.15 0.20 0.25 0.30

Mole Fraction Figure E-1 CO2 in [emim][Tf2N] in flowing and static mode

278

APPENDIX F

RAW DATA FOR HIGH PRESSURE CARBON DIOXIDE SOLUBILITY

MEASUREMENTS

This appendix includes the raw data from the high pressure measurements of CO2

o solubility in wet and dry samples of [bmim][Tf2N] at 25 C.

TABLE F-1

DRY SAMPLES (CONTAINING <500 PPM H2O)

[bmim][Tf2N] o T ( C) P (bar) mol frac CO2 mol frac 25.03 11.63 0.729 0.271 + 0.013 25.03 20.84 0.589 0.411 + 0.009 25.03 31.69 0.476 0.524 + 0.007 25.03 46.94 0.351 0.649 + 0.006

[bmim][Tf2N] o T ( C) P (bar) mol frac CO2 mol frac 25.03 11.65 0.748 0.252 + 0.013 25.03 22.28 0.597 0.403 + 0.009 25.03 33.96 0.466 0.534 + 0.007 25.02 44.27 0.382 0.618 + 0.006 25.02 58.76 0.294 0.706 + 0.006

[bmim][Tf2N] o T ( C) P (bar) mol frac CO2 mol frac 25.02 11.38 0.732 0.268 + 0.014 25.03 22.24 0.578 0.422 + 0.009 25.03 33.59 0.469 0.531 + 0.007 25.03 46.67 0.364 0.636 + 0.006 25.03 60.35 0.283 0.717 + 0.006

279 TABLE F-2

WATER SATURATED SAMPLE (CONTAINING 1.58 + 0.3 WT% H2O)

[bmim][Tf2N] o T ( C) P (bar) mol frac CO2 mol frac 25.02 17.43 0.638 0.362 + 0.021 25.00 29.77 0.464 0.536 + 0.014 25.04 45.25 0.357 0.643 + 0.008 25.04 59.54 0.287 0.713 + 0.007

280

REFERENCES

1. Seddon, K. R., Room-temperature ionic liquids: Neoteric solvents for clean catalysis. Kinet. Catal., 1996. 37(5): 693-697.

2. Hussey, C. L., Room-temperature haloaluminate ionic liquids - Novel solvents for transition-metal solution chemistry. Pure Appl. Chem., 1988. 60(12): 1763-1772.

3. Wilkes, J. S. and Zaworotko, M. J., Air and water stable 1-ethyl-3- methylimidazolium based ionic liquids. J. Chem. Soc.-Chem. Commun., 1992. (13): 965-967.

4. Bonhote, P., Dias, A. P., Papageorgiou, N., Kalyanasundaram, K., and Gratzel, M., Hydrophobic, highly conductive ambient-temperature molten salts. Inorg. Chem., 1996. 35(5): 1168-1178.

5. Seddon, K. R., Stark, A., and Torres, M. J., Influence of chloride, water, and organic solvents on the physical properties of ionic liquids. Pure Appl. Chem., 2000. 72(12): 2275-2287.

6. Anthony, J. L., Maginn, E. J., and Brennecke, J. F., Solution thermodynamics of imidazolium-based ionic liquids and water. J. Phys. Chem. B, 2001. 105: 10942-10949.

7. Anthony, J. L., Maginn, E. J., and Brennecke, J. F., Solubilities and thermodynamic properties of gases in the ionic liquid 1-n-butyl-3- methylimidazolium hexafluorophosphate. J. Phys. Chem. B, 2002. 106(29): 7315-7320.

8. Anthony, J. L., Crosthwaite, J. M., Hert, D. G., Aki, S. N. V. K., Maginn, E. J., and Brennecke, J. F., Phase equilibria of gases and liquids with 1-n-butyl- 3-methylimidazolium tetrafluoroborate, in Ionic Liquids as Green Solvents, R. D. Rogers and K. R. Seddon, Editors. 2003, American Chemical Society: Washington D.C. p. 110-120.

281 9. Holbrey, J. D. and Seddon, K. R., Ionic liquids. Clean Products and Processes, 1999. 1: 223-236.

10. Welton, T., Room-temperature ionic liquids. Solvents for synthesis and catalysis. Chem. Rev., 1999. 99(8): 2071-2083.

11. Wasserscheid, P. and Keim, W., Ionic liquids - New "solutions" for transition metal catalysis. Angew. Chem.-Int. Edit., 2000. 39(21): 3773-3789.

12. Seddon, K. R., Stark, A., and Torres, M. J., Viscosity and density of 1-alkyl-3- methylimidazolium ionic liquids, in Clean Solvents, M. Abraham and L. Moens, Editors. 2002, American Chemical Society: Washington D.C. p. 34- 49.

13. Mantz, R. A. and Trulove, P. C., Viscosity and density of ionic liquids. 2003.: 56-68.

14. Pringle, J. M., Golding, J., Baranyai, K., Forsyth, C. M., Deacon, G. B., Janet, L. S. A., and MacFarlane, D. R., The effect of anion fluorination in ionic liquids - physical properties of a range of bis(methanesulfonyl)amide salts. 2003. 27(10): 1504-1510.

15. Noda, A., Hayamizu, K., and Watanabe, M., Pulsed-gradient spin-echo H-1 and F-19 NMR ionic diffusion coefficient, viscosity, and ionic conductivity of non-chloroaluminate room-temperature ionic liquids. J. Phys. Chem. B, 2001. 105(20): 4603-4610.

16. Dzyuba, S. V. and Bartsch, R. A., Influence of structural variations in 1- alkyl(aralkyl)-3- methylimidazolium hexafluorophosphates and bis(trifluorormethyl-sulfonyl)imides on physical properties of the ionic liquids. ChemPhysChem, 2002. 3(2): 161.

17. Gu, Z. Y. and Brennecke, J. F., Volume expansivities and isothermal compressibilities of imidazolium and pyridinium-based ionic liquids. J. Chem. Eng. Data, 2002. 47(2): 339-345.

18. Fredlake, C. P., Crosthwaite, J. M., Hert, D. G., Aki, S. N. V. K., and Brennecke, J. F., Thermophysical properties of imidazolium-based ionic liquids. J. Chem. Eng. Data, 2003.: submitted.

19. Huddleston, J. G., Visser, A. E., Reichert, W. M., Willauer, H. D., Broker, G. A., and Rogers, R. D., Characterization and comparison of hydrophilic and hydrophobic room temperature ionic liquids incorporating the imidazolium cation. Green Chem., 2001. 3(4): 156-164.

282 20. Suarez, P. A. Z., Einloft, S., Dullius, J. E. L., De Souza, R. F., and Dupont, J., Synthesis and physical-chemical properties of ionic liquids based on 1-n- butyl-3-methylimidazolium cation. J. Chim. Phys., 1998. 95(7): 1626-1639.

21. Branco, L. C., Rosa, J. N., Ramos, J. J. M., and Afonso, C. A. M., Preparation and characterization of new room temperature ionic liquids. Chem.-Eur. J., 2002. 8(16): 3671-3677.

22. Ngo, H. L., LeCompte, K., Hargens, L., and McEwen, A. B., Thermal properties of imidazolium ionic liquids. Thermochim. Acta, 2000. 357: 97- 102.

23. Matsumoto, H., Kageyama, H., and Miyazaki, Y., Room temperature ionic liquids based on small aliphatic ammonium cations and asymmetric amide anions. Chem. Commun., 2002. (16): 1726-1727.

24. Holbrey, J. D. and Seddon, K. R., The phase behaviour of 1-alkyl-3- methylimidazolium tetrafluoroborates; ionic liquids and ionic liquid crystals. J. Chem. Soc.-Dalton Trans., 1999. (13): 2133-2139.

25. MacFarlane, D. R., Golding, J., Forsyth, S., Forsyth, M., and Deacon, G. B., Low viscosity ionic liquids based on organic salts of the dicyanamide anion. Chem. Commun., 2001. (16): 1430-1431.

26. Awad, W. H., Gilman, J. W., Nyden, M., Harris, R. H., Jr., Sutto, T. E., Callahan, J., Trulove, P. C., DeLong, H. C., and Fox, D. M., Thermal degradation studies of alkyl-imidazolium salts and their application in nanocomposites. Thermochim. Acta, 2003.: ASAP article.

27. Kosmulski, M., Gustafsson, J., and Rosenholm, J. B., Thermal stability of low temperature ionic liquids revisited. Thermochim. Acta, 2003.: ASAP article.

28. Magee, J. W. Heat capacity and enthalpy of fusion for 1-butyl-3-methyl- imidazolium hexafluorophosphate. in 17th IUPAC Conference on Chemical Thermodynamics (ICCT 2002). 2002. Rostock, Germany.

29. Paulechka, Y. U., Kabo, G. J., Blokhin, A. V., Vydrov, O. A., Magee, J. W., and Frenkel, M., Thermodynamic properties of 1-butyl-3-methylimidazolium hexafluorophosphate in the ideal gas state. 2003. 48(3): 457-462.

30. Holbrey, J. D., Reichardt, W. M., Reddy, R. G., and Rogers, R. D., Head capacities of ionic liquids and their applications as thermal fluids, in Ionic Liquids as Green Solvents, R. D. Rogers and K. R. Seddon, Editors. 2003, American Chemical Society: Washington D.C. p. 121-133.

283 31. Van Valkenburg, M. E., Vaughn, R. L., Williams, M., and Wilkes, J. S. Ionic liquid heat transfer fluids. in Fifteenth Symposium on Thermophysical Properties. 2003. Boulder, CO.

32. Hagiwara, R. and Ito, Y., Room temperature ionic liquids of alkylimidazolium cations and fluoroanions. J. Fluor. Chem., 2000. 105(2): 221-227.

33. Poole, C. F., Chromatographic and spectroscopic methods for the determination of solvent properties of room temperature ionic liquids. J. Chromat. A, 2003.: ASAP article.

34. Wu, C. T., Marsh, K. N., Deev, A. V., and Boxall, J. A., Liquid-liquid equilibria of room-temperature ionic liquids and butan-1-ol. J. Chem. Eng. Data, 2003. 48(3): 486-491.

35. Najdanovic-Visak, V., Esperanca, J. M. S. S., Rebelo, L. P. N., Nunes da Ponte, M., Guedes, H. J. R., Seddon, K. R., and Szydlowski, J., Phase behaviour of room temperature ionic liquid solutions: an unusually large co- solvent effect in (water + ethanol). Phys. Chem. Chem. Phys., 2002. 4(10): 1701-1703.

36. Domanska, U., Bogel-Lukasik, E., and Bogel-Lukasik, R., Solubility of 1- dodecyl-3-methylimidazolium chloride in alcohols (C2-C12). J. Phys. Chem. B, 2003. 107(8): 1858-1863.

37. Domanska, U., Bogel-Lukasik, E., and Bogel-Lukasik, R., 1-octanol/water partition coefficients of 1-alkyl-3- methylimidazolium chloride. Chem.-Eur. J., 2003. 9(13): 3033-3041.

38. Heintz, A., Lehmann, J. K., and Wertz, C., Thermodynamic properties of mixtures containing ionic liquids. 3. Liquid-liquid equilibria of binary mixtures of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide with propan-1-ol, butan-1-ol, and pentan-1-ol. J. Chem. Eng. Data, 2003. 48(3): 472-474.

39. Wagner, M., Stanga, O., and Schroer, W., Corresponding states analysis of the critical points in binary solutions of room temperature ionic liquids. Phys. Chem. Chem. Phys, 2003. 5(18): 3943-3950.

40. Crosthwaite, J. M., Aki, S. N. V. K., Maginn, E. J., and Brennecke, J. F., Liquid phase behavior of imidazolium-based ionic liquids with alcohols. J. Phys. Chem. B, 2003.: submitted.

41. Domanska, U. and Marciniak, A., Solubility of 1-alkyl-3-methylimidazolium hexafluorophosphate in hydrocarbons. J. Chem. Eng. Data, 2003. 48(3): 451- 456.

284

42. Dullius, J. E. L., Suarez, P. A. Z., Einloft, S., de Souza, R. F., Dupont, J., Fischer, J., and De Cian, A., Selective catalytic hydrodimerization of 1,3- butadiene by palladium compounds dissolved in ionic liquids. Organometallics, 1998. 17(5): 815-819.

43. Swatloski, R. P., Visser, A. E., Reichert, W. M., Broker, G. A., Farina, L. M., Holbrey, J. D., and Rogers, R. D., Solvation of 1-butyl-3-methylimidazolium hexafluorophosphate in aqueous ethanol-a green solution for dissolving 'hydrophobic' ionic liquids. Chem. Commun., 2001. (20): 2070-2071.

44. Swatloski, R. P., Visser, A. E., Reichert, W. M., Broker, G. A., Farina, L. M., Holbrey, J. D., and Rogers, R. D., On the solubilization of water with ethanol in hydrophobic hexafluorophosphate ionic liquids. Green Chem., 2002. 4(2): 81-87.

45. Krummen, M., Gruber, D., and Gmehling, J., Measurement of activity coefficients at infinite dilution in ionic liquids using the dilutor technique. J. Chem. Eng. Data, 2002. 47: 1411-1417.

46. Heintz, A., Kulikov, D. V., and Verevkin, S. P., Thermodynamic properties of mixtures containing ionic liquids. 1. Activity coefficients at infinite dilution of alkanes, alkenes, and alkylbenzenes in 4-methyl-n-butylpyridinium tetrafluoroborate using gas-liquid chromatography. J. Chem. Eng. Data, 2001. 46(6): 1526-1529.

47. Heintz, A., Kulikov, D. V., and Verevkin, S. P., Thermodynamic properties of mixtures containing ionic liquids. Activity coefficients at infinite dilution of polar solutes in 4-methyl-N-butyl-pyridinium tetrafluoroborate using gas- liquid chromatography. J. Chem. Thermodyn., 2002. 34(8): 1341-1347.

48. Heintz, A., Kulikov, D. V., and Verevkin, S. P., Thermodynamic properties of mixtures containing ionic liquids. 2. Activity coefficients at infinite dilution of hydrocarbons and polar solutes in 1-methyl-3-ethyl-imidazolium bis(trifluoromethyl-sulfonyl) amide and in 1,2-dimethyl-3- ethyl-imidazolium bis(trifluoromethyl-sulfonyl) amide using gas-liquid chromatography. J. Chem. Eng. Data, 2002. 47(4): 894-899.

49. Heintz, A., Lehmann, J. K., and Verevkin, S. P., Thermodynamic properties of liquid mixtures containing ionic liquids, in Ionic Liquids as Green Solvents: Progress and Prospects, R. D. Rogers and K. R. Seddon, Editors. 2003, American Chemical Society: Washington D.C. p. 134-150.

50. David, W., Letcher, T. M., Ramjugernath, D., and Raal, J. D., Activity coefficients of hydrocarbon solutes at infinite dilution in the ionic liquid, 1-

285 methyl-3-octyl-imidazolium chloride from gas-liquid chromatography. J. Chem. Thermodyn., 2003. 35(8): 1335-1341.

51. Letcher, T. M., Soko, B., Ramjugernath, D., Deenadayalu, N., Nevines, A., and Naicker, P. K., Activity coefficients at infinite dilution of organic solutes in 1-hexyl-3-methylimidazolium hexafluorophosphate from gas-liquid chromatography. J. Chem. Eng. Data, 2003. 48(3): 708-711.

52. Selvan, M. S., McKinley, M. D., Dubois, R. H., and Atwood, J. L., Liquid- liquid equilibria for toluene plus heptane+1-ethyl-3- methylimidazolium triiodide and toluene plus heptane+1-butyl-3- methylimidazolium triiodide. J. Chem. Eng. Data, 2000. 45(5): 841-845.

53. Blanchard, L. A. and Brennecke, J. F., Recovery of organic products from ionic liquids using supercritical carbon dioxide. Ind. Eng. Chem. Res., 2001. 40(1): 287-292.

54. Blanchard, L. A. and Brennecke, J. F., Recovery of organic products from ionic liquids using supercritical carbon dioxide (erratum). Ind. Eng. Chem. Res., 2001. 40(11): 2550.

55. Holbrey, J. D., Reichardt, W. M., Nieuwenhuyzen, M., Sheppard, O., Hardacre, C., and Rogers, R. D., Liquid clathrate formation in ionic liquid- aromatic mixtures. Chem. Commun., 2003. 2003: 476-477.

56. Zhang, J. M., Wu, W. Z., Jiang, T., Gao, H. X., Liu, Z. M., He, J., and Han, B. X., Conductivities and viscosities of the ionic liquid [bmim][PF6] plus water plus ethanol and [bmim][PF6] plus water plus acetone ternary mixtures. 2003. 48(5): 1315-1317.

57. Wang, J. J., Tian, Y., Zhao, Y., and Zhuo, K., A volumetric and viscosity study for the mixtures of 1-n-butyl-3-methylimidazolium tetrafluoroborate ionic liquid with acetonitrile, dichloromethane, 2-butanone and N,N- dimethylformamide. 2003. 5(5): 618-622.

58. Fadeev, A. G. and Meagher, M. M., Opportunities for ionic liquids in recovery of biofuels. Chem. Commun., 2001.: 295-296.

59. Wong, D. S. H., Chen, J. P., Chang, J. M., and Chou, C. H., Phase equilibria of water and ionic liquids [emim][PF6] and [bmim][PF6]. Fluid Phase Equilib., 2002. 194-197: 1089-1095.

60. Alfassi, Z. B., Huie, R. E., Milman, B. L., and Neta, P., Electrospray ionization mass spectrometry of ionic liquids and determination of their solubility in water. 2003. 377(1): 159-164.

286 61. Blanchard, L. A., Gu, Z. Y., and Brennecke, J. F., High-pressure phase behavior of ionic liquid/CO2 systems. J. Phys. Chem. B, 2001. 105(12): 2437- 2444.

62. Blanchard, L. A., Hancu, D., Beckman, E. J., and Brennecke, J. F., Green processing using ionic liquids and CO2. Nature, 1999. 399(6731): 28-29.

63. Bates, E. D., Mayton, R. D., Ntai, I., and Davis, J. H., Jr., CO2 capture by a task-specific ionic liquid. J. Am. Chem. Soc., 2002. 124(6): 926-927.

64. Berger, A., de Souza, R. F., Delgado, M. R., and Dupont, J., Ionic liquid- phase asymmetric catalytic hydrogenation: hydrogen concentration effects on enantioselectivity. Tetrahedron: Asymmetry, 2001. 12(13): 1825-1828.

65. Anthony, J. L., Maginn, E. J., and Brennecke, J. F., Gas solubilities in 1-n- butyl-3-methylimidazolium hexafluorophosphate, in Ionic Liquids, R. D. Rogers and K. R. Seddon, Editors. 2002, American Chemical Society: Washington D.C. p. 260-269.

66. Husson-Borg, P., Majer, V., and Costa Gomes, M. F., Solubilities of oxygen and carbon dioxide in butyl methyl imidazolium tetrafluoroborate as a function of temperature and at pressures close to atmospheric pressure. J. Chem. Eng. Data, 2003. 48(3): 480-485.

67. Kamps, A. P. S., Tuma, D., Xia, J. Z., and Maurer, G., Solubility of CO2 in the ionic liquid [bmim][PF6]. J. Chem. Eng. Data, 2003. 48(3): 746-749.

68. Baltus, R. E., Culbertson, B. H., Dai, S., Luo, H., and DePaoli, D., Low- pressure solubility of carbon dioxide in room-temperature ionic liquids measured with a quartz crystal microbalance. J. Phys. Chem. B, 2003.: ASAP article.

69. Shariati, A. and Peters, C. J., High-pressure phase behavior of systems with ionic liquids Part III. The binary system carbon dioxide + 1-hethyl-3- methylimidazolium hexafluorophosphate. J. Supercrit. Fluids, 2003.: ASAP article.

70. Dyson, P. J., Laurenczy, G., Ohlin, C. A., Vallance, J., and Welton, T., Determination of hydrogen concentration in ionic liquids and the effect (or lack of) on rates of hydrogenation. 2003. (19): 2418-2419.

71. Buzzeo, M. C., Klymenko, O. V., Wadhawan, J. D., Hardacre, C., Seddon, K. R., and Compton, R. G., Voltammetry of oxygen in the room-temperature ionic liquids 1-ethyl-3-methylimidazolium bis((trifluoromethyl)sulfonyl)imide and hexyltriethylammonium bis((trifluoromethyl)sulfonyl)imide: One-electron reduction to form superoxide. Steady-state and transient behavior in the same

287 cyclic voltammogram resulting from widely different diffusion coefficients of oxygen and superoxide. 2003. 107(42): 8872-8878.

72. Shariati, A. and Peters, C. J., High-pressure phase behavior of systems with ionic liquids: measurements and modeling of the binary system fluoroform + 1-ethyl-3-methylimidazolium hexafluorophosphate. J. Supercrit. Fluids, 2003. 25: 109-117.

73. Aki, S. N., Brennecke, J. F., and Samanta, A., How polar are room- temperature ionic liquids? Chem. Commun., 2001. 5: 413-414.

74. Carmichael, A. J. and Seddon, K. R., Polarity study of some 1-alkyl-3- methylimidazolium ambient- temperature ionic liquids with the solvatochromic dye, Nile Red. J. Phys. Org. Chem., 2000. 13(10): 591-595.

75. Baker, S. N., Baker, G. A., and Bright, F. V., Temperature-dependent microscopic solvent properties of 'dry' and 'wet' 1-butyl-3-methylimidazolium hexafluorophosphate: correlation with ET(30) and Kamlet-Taft polarity scales. Green Chem., 2002. 4(2): 165-169.

76. Muldoon, M. J., Gordon, C. M., and Dunkin, I. R., Investigations of solvent- solute interactions in room temperature ionic liquids using solvatochromic dyes. J. Chem. Soc.-Perkin Trans. 2, 2001. (4): 433-435.

77. Karmakar, R. and Samanta, A., Solvation dynamics of coumarin-153 in a room-temperature ionic liquid. J. Phys. Chem. A, 2002. 106(18): 4447-4452.

78. Ingram, J. A., Moog, R. S., Ito, N., Biswas, R., and Maroncelli, M., Solute rotation and solvation dynamics in a room-temperature ionic liquid. J. Phys. Chem. B, 2003. 107(24): 5926-5932.

79. Karmakar, R. and Samanta, A., Steady-state and time-resolved fluorescence behavior of C153 and PRODAN in room-temperature ionic liquids. J. Phys. Chem. A, 2002. 106(28): 6670-6675.

80. Fletcher, K. A., Storey, I. A., Hendricks, A. E., and Pandey, S., Behavior of the solvatochromic probes Reichardt's dye, pyrene, dansylamide, Nile Red and 1-pyrenecarbaldehyde within the room-temperature ionic liquid [bmim][PF6]. Green Chem., 2001. 3(5): 210-215.

81. Baker, S. N., Baker, G. A., Kane, M. A., and Bright, F. V., The cybotactic region surrounding fluorescent probes dissolved in 1-butyl-3- methylimidazolium hexafluorophosphate: Effects of temperature and added carbon dioxide. J. Phys. Chem. B, 2001. 105(39): 9663-9668.

288 82. Meng, Z., Dolle, A., and Carper, W. R., Gas phase model of an ionic liquid: semi-empirical and ab initio bonding and molecular structure. Theochem-J. Mol. Struct., 2002. 585: 119-128.

83. Hanke, C. G., Price, S. L., and Lynden-Bell, R. M., Intermolecular potentials for simulations of liquid imidazolium salts. Mol. Phys., 2001. 99(10): 801- 809.

84. Hanke, C. G., Atamas, N. A., and Lynden-Bell, R. M., Solvation of small molecules in imidazolium ionic liquids: a simulation study. Green Chem., 2002. 4(2): 107-111.

85. Lynden-Bell, R. M., Atamas, N. A., Vasilyuk, A., and Hanke, C. G., Chemical potentials of water and organic solutes in imidazolium ionic liquids: a simulation study. Mol. Phys., 2002. 100(20): 3225-3229.

86. Shah, J. K., Brennecke, J. F., and Maginn, E. J., Thermodynamic properties of the ionic liquid 1-n-butyl-3-methylimidazolium hexafluorophosphate from Monte Carlo simulations. Green Chem., 2002. 4(2): 112-118.

87. Morrow, T. I. and Maginn, E. J., Molecular dynamics study of the ionic liquid 1-n-butyl-3-methylimidazolium hexafluorophosphate. 2002. 106(49): 12807- 12813.

88. Morrow, T. I. and Maginn, E. J., Molecular dynamics study of the ionic liquid 1-n-butyl-3-methylimidazolium hexafluorophosphate (erratum). 2003. 107(34): 9160-9160.

89. Margulis, C. J., Stern, H. A., and Berne, B. J., Computer simulation of a "green chemistry" room-temperature ionic solvent. J. Phys. Chem. B, 2002. 106(46): 12017-12021.

90. de Andrade, J., Boes, E. S., and Stassen, H., A force field for liquid state simulations on room temperature molten salts: 1-ethyl-3-methylimidazolium tetrachloroaluminate. J. Phys. Chem. B, 2002. 106(14): 3546-3548.

91. de Andrade, J., Boes, E. S., and Stassen, H., Computational study of room temperature molten salts composed by 1-alkyl-3-methylimidazolium cations- force-field proposal and validation. J. Phys. Chem. B, 2002. 106(51): 13344- 13351.

92. Hanke, C. G., Johansson, A., Harper, J. B., and Lynden-Bell, R. M., Why are aromatic compounds more soluble than aliphatic compounds in dimethylimidazolium ionic liquids? A simulation study. 2003. 374(1-2): 85-90.

289 93. Hanke, C. G. and Lynden-Bell, R. M., A simulation study of water- dialkylimidazolium ionic liquid mixtures. 2003. 107(39): 10873-10878.

94. Lynden-Bell, R. M., Gas-liquid interfaces of room temperature ionic liquids. 2003. 101(16): 2625-2633.

95. Cadena, C., Anthony, J. L., Shah, J. K., Morrow, T. I., Brennecke, J. F., and Maginn, E. J., Why is CO2 so soluble in imidazolium-based ionic liquids? J. Am. Chem. Soc., 2003.: submitted.

96. Shah, J. K., Brennecke, J. F., and Maginn, E. J., A Monte Carlo simulation study of the ionic liquid 1-n-butyl-3-methylimidazolium hexafluorophosphate: Liquid structure, volumetric properties and infinite dilution solution thermodynamics of CO2. Fluid Phase Equil., 2003.: submitted.

97. Znamenskiy, V. and Kobrak, M. N., Molecular Dynamics Study of Polarity in Room-Temperature Ionic Liquids. J. Phys. Chem. B, 2003.: ASAP article.

98. Brennecke, J. F. and Maginn, E. J., Ionic liquids: Innovative fluids for chemical processing. AIChE J., 2001. 47: 2140.

99. Visser, A. E., Swatloski, R. P., Reichert, W. M., Griffin, S. T., and Rogers, R. D., Traditional extractants in nontraditional solvents: Groups 1 and 2 extraction by crown ethers in room-temperature ionic liquids. Ind. Eng. Chem. Res., 2000. 39(10): 3596-3604.

100. Visser, A. E., Swatloski, R. P., Reichert, W. M., Mayton, R., Sheff, S., Wierzbicki, A., Davis, J. H., and Rogers, R. D., Task-specific ionic liquids for the extraction of metal ions from aqueous solutions. Chem. Commun., 2001. (01): 135-136.

101. Visser, A. E., Swatloski, R. P., and Rogers, R. D., pH-dependent partitioning in room temperature ionic liquids provides a link to traditional solvent extraction behavior. Green Chem., 2000. 2(1): 1-4.

102. Huddleston, J. G., Willauer, H. D., Swatloski, R. P., Visser, A. E., and Rogers, R. D., Room temperature ionic liquids as novel media for 'clean' liquid-liquid extraction. Chem. Commun., 1998. (16): 1765-1766.

103. Ranke, J., Moelter, K., Stock, F., Bottin-Weber, U., Poczobutt, J., Hoffmann, J., Ondruschka, B., Filser, J., and Jastorff, B., Biological effects of imidazolium ionic liquids with varying chain lengths in acute Vibrio fischeri and WST-1 cell viability assays. Ecotox. and Env. Safety, 2003.: ASAP article.

290 104. Bernot, R. J., Brueseke, M., Evans-White, M., and Lamberti, G. A., Acute and chronic toxicity of imidazolium-based ionic liquids Daphnia magna. Env. Tox. and Chem., submitted.

105. Letcher, T. M., Deenadayalu, N., Soko, B., Ramjugernath, D., and Naicker, P. K., Ternary liquid-liquid equilibria for mixtures of 1-methyl-3- octylimidazolium chloride plus an alkanol plus an alkane at 298.2 K and 1 bar. J. Chem. Eng. Data, 2003. 48(4): 904-907.

106. Zhang, S. G. and Zhang, Z. C., Novel properties of ionic liquids in selective sulfur removal from fuels at room temperature. Green Chem., 2002. 4(4): 376-379.

107. Lo, W. H., Yang, H. Y., and Wei, G. T., One-pot desulfurization of light oils by chemical oxidation and solvent extraction with room temperature ionic liquids. 2003. 5(5): 639-642.

108. Gmehling, J. and Krummen, M., Use of ionic liquids as entraining agents and selective solvents for separation of aromatic hydrocarbons in aromatic petroleum streams, DE Patent 10154052, 2003.

109. Arlt, W., Seiler, M., Jork, C., and Schneider, T., Ionic liquids as selective additives for the separation of close-boiling or azeotropic mixtures, DE Patent 10136614, 2002.

110. Scurto, A. M., Aki, S., and Brennecke, J. F., CO2 as a separation switch for ionic liquid/organic mixtures. J. Am. Chem. Soc., 2002. 124(35): 10276- 10277.

111. Scurto, A. M., Aki, S., and Brennecke, J. F., Carbon dioxide induced separation of ionic liquids and water. Chem. Commun., 2003. (5): 572-573.

112. Anthony, J. L., Aki, S. N. V. K., Maginn, E. J., and Brennecke, J. F., Feasibility of using ionic liquids for carbon dioxide capture. Int. J. Env. Tech. Manag., 2003.: in press.

113. Anthony, J. L., Gu, Z. Y., Blanchard, L. A., Maginn, E. J., and Brennecke, J. F., Gas solubility in ionic liquids. Abstracts of Papers of the American Chemical Society, 2001. 221: 276-IEC.

114. Scovazzo, P., Visser, A. E., Davis, J. H., Rogers, R. D., Noble, R. D., and Koval, C., Supported ionic liquid membranes and facilitated ionic liquid membranes. Abstracts of Papers of the American Chemical Society, 2001. 221: 28-IEC.

291 115. Culbertson, B. H., Baltus, R. E., Dai, S., Luo, H., and DePaoli, D. Examination of the potential of room temperature ionic liquids for carbon dioxide removal from flue gases. in AIChE Annual Meeting. 2003. San Francisco, CA.

116. Clever, H. L. and Battino, R., The solubility of gases in liquids, in Techniques of Chemistry Volume VIII: Solutions and Solubilities - Part 1, M. R. J. Dack, Editor. 1975, John Wiley & Sons, Inc.: New York. p. 380- 441.

117. Wilhelm, E., Solubility of gases in liquids: a critical review. Pure & Appl. Chem., 1985. 57(2): 303-322.

118. Kohn, J. P., Heterogeneous phase and volumetric behavior of the methane-N- heptane system at low temperature. AIChE J., 1961. 7: 514-518.

119. Scurto, A. M., High-Pressure Phase and Chemical Equilibria of β-diketone Ligands and Chelates with Carbon Dioxide, Ph.D. Thesis. Department of Chemical Engineering, University of Notre Dame, Notre Dame, IN, 2002.

120. Krummen, M., Gruber, D., and Gmehling, J., Measurement of activity coefficients at infinite dilution in solvent mixtures using the dilutor technique. Ind. Eng. Chem. Res., 2000. 39(6): 2114-2123.

121. Prausnitz, J. M., Lichtenthaler, R. N., and de Azevedo, E. G., Molecular Thermodynamics of Fluid-Phase Equilibria. 3rd ed. 1999, Upper Saddle River, NJ: Prentice Hall.

122. Hildebrand, J. H. and Scott, R. L., Regular solutions. 1962, Englewood Cliffs, NJ: Prentice Hall.

123. Hilgers, C. and Wasserscheid, P., Quality aspects and other questions related to commercial ionic liquid production, in Ionic Liquids in Synthsis, P. Wasserscheid and T. Welton, Editors. 2003, Wiley-VHC Verlag: Weinhein. p. 21-32.

124. Gordon, C. M., Holbrey, J. D., Kennedy, A. R., and Seddon, K. R., Ionic liquid crystals: hexafluorophosphate salts. J. Mater. Chem., 1998. 8(12): 2627-2636.

125. Verkman, A. S., Development and biological applications of chloride- sensitive fluorescent indicators. Am. J. Physiol., 1990. 259(3): C375-C388.

126. Verkman, A. S., Sellers, M. C., Chao, A. C., Leung, T., and Ketcham, R., Synthesis and characterization of improved chloride-sensitive fluorescent indicators for biological applications. Anal. Biochem., 1989. 178(2): 355- 361.

292

127. Cammarata, L., Kazarian, S. G., Salter, P. A., and Welton, T., Molecular states of water in room temperature ionic liquids. Phys. Chem. Chem. Phys., 2001. 3(23): 5192-5200.

128. Behar, D., Neta, P., and Schultheisz, C., Reaction kinetics in ionic liquids as studied by pulse radiolysis: Redox reactions in the solvents methyltributylammonium bis(trifluoromethylsulfonyl)imide and N- butylpyridinium tetrafluoroborate. J. Phys. Chem. A, 2002. 106(13): 3139- 3147.

129. Skrzypczak, A. and Neta, P., Diffusion-controlled electron-transfer reactions in ionic liquids. J. Phys. Chem. A, 2003. 107(39): 7800-7803.

130. Moore, D. D., Experimental Studies of Gas Adsorption on Microporous Materials, M.S. Thesis. Department of Chemical Engineering, University of Notre Dame, Notre Dame, IN, 2000.

131. Macedonia, M. D., Moore, D. D., Maginn, E. J., and Olken, M. M., Adsorption studies of methane, ethane, and argon in the zeolite mordenite: Molecular simulations and experiments. Langmuir, 2000. 16(8): 3823-3834.

132. Span, R. and Wagner, W., A new equation of state for carbon dioxide covering the fluid region from the triple-point temperature to 1100 K at pressures up to 800 MPa. J. Phys. Chem. Ref. Data, 1996. 25(6): 1509-1596.

133. Schmidt, R. and Wagner, W., A new form of the equation of state for pure substances and its application to oxygen. Fluid Phase Equilib., 1985. 19(3): 175-200.

134. Span, R., Lemmon, E. W., Jacobsen, R. T., and Wagner, W., A reference quality equation of state for nitrogen. Int. J. Thermophys., 1998. 19(4): 1121- 1132.

135. Tegeler, C., Span, R., and Wagner, W., A new equation of state for argon covering the fluid region for temperatures from the melting line to 700 K at pressures up to 1000 MPa. J. Phys. Chem. Ref. Data, 1999. 28(3): 779-850.

136. Cooper, H. W. and Goldfrank, J. C., B-W-R constants and new correlations. Hydrocarbon Proc., 1967. 46(12): 141-146.

137. Oyre, R. V., Prediction and correlation of phase equilibria and thermal properties with the BWR equation of state. Ind. Eng. Chem. Proc. Dev., 1969. 8(4): 579.

293 138. Law, G. and Watson, P. R., Surface tension measurements of N- alkylimidazolium ionic liquids. Langmuir, 2001. 17(20): 6138-6141.

139. Hardacre, C. Halide determination in ionic liquids. in 226th ACS National Meeting. 2003. New York, NY.

140. Crosthwaite, J. M., Ropel, L. J., Anthony, J. L., Aki, S. N. V. K., Maginn, E. J., and Brennecke, J. F., Phase equilibria with gases and liquids of 1-n-butyl- 3-methylimidazolium trifluoromethanesulfonylimide, in ACS Symposium Series, R. D. Rogers and K. R. Seddon, Editors. 2003, submitted.

141. Kazarian, S. G., Briscoe, B. J., and Welton, T., Combining ionic liquids and supercritical fluids: in situ ATR- IR study of CO2 dissolved in two ionic liquids at high pressures. Chem. Commun., 2000. (20): 2047-2048.

142. Crowhurst, L., Mawdsley, P. R., Perez-Arlandis, J. M., Salter, P. A., and Welton, T., Solvent-solute interactions in ionic liquids. Phys. Chem. Chem. Phys., 2003. 5: 2790-2794.

143. Weast, R. C., Astle, M. J., and Beyer, W. H., eds. CRC Handbook of Chemistry and Physics. 64th ed. 1984, CRC Press, Inc.: Boca Raton, FL.

144. Stogryn, D. E. and Stogryn, A. P., Molecular multipole moments. Mol. Phys., 1966. 11: 371-393.

145. Hirschfelder, J. O., Curtiss, C. F., and Bird, R. B., Molecular theory of gases and liquids. Vol. 12. 1954, New York: Wiley.

146. Wilhelm, E. and Battino, R., Thermodynamic functions of the solubilities of gases in liquids at 25oC. Chem. Rev., 1973. 73(1): 1-9.

147. Goldman, S., The determination and statistical mechanical interpretation of the solubility of water in benzene, carbon tetrachloride, and cyclohexane. Can. J. Chem., 1974. 88: 1668.

148. Gmehling, J., Menke, J., and Schiller, M., Activity coefficients at infinite dilution. Vol. 9. 1994, Frankfurt: DECHEMA.

149. Safarik, D. J. and Eldridge, R. B., Olefin/paraffin separations by reactive absorption: A review. Ind. Eng. Chem. Res., 1998. 37(7): 2571-2581.

150. McEwen, A. B., Ngo, H. L., LeCompte, K., and Goldman, J. L., Electrochemical properties of imidazolium salt electrolytes for electrochemical capacitor applications. J. Electrochem. Soc., 1999. 146(5): 1687-1695.

294 151. Jureviciute, I., Bruckenstein, S., and Hillman, A. R., Counter-ion specific effects on charge and solvent trapping in poly(vinylferrocene) films. J. Electroanal. Chem., 2000. 488: 73-81.

152. Smith, J. M., Van Ness, H. C., and Abbott, M. M., Introduction to Chemical Engineering Thermodynamics. 5th ed. 1996: McGraw Hill.

153. Glasoe, P. K. and Schultz, S. D., Solubility of H2O and D2O in carbon tetrachloride, toluene, and cyclohexane at various temperatures. J. Chem. Eng. Data, 1972. 17(1): 66-68.

154. Polak, J. and Lu, B. C. Y., Mutual solubilities of hydrocarbons and water at 0 and 25 oC. Can. J. Chem., 1973. 51: 4018-4023.

155. Lo, J. M., Tseng, C. L., and Yang, J. Y., Radiometric method for determining solubility of organic solvents in water. Anal. Chem., 1986. 58(7): 1596-1597.

156. Fossey, L. and Cantwell, F. F., Determination of acidity constants by solvent extraction/flow injection analysis using a dual-membrane phase separator. Anal. Chem., 1985. 57: 922-926.

157. Sorensen, J. M. and Arlt, W., Liquid-Liquid Equilibrium Data Collection, Binary Systems. Chemistry Data Series, ed. D. Behrens and R. Eckermann. Vol. 5. 1979, Frankfurt: DECHEMA.

158. Chatzopoulos, D. and Varma, A., Aqueous-phase adsorption and desorption of toluene in activated carbon fixed-beds - experiments and model. Chem. Eng. Sci., 1995. 50(1): 127-141.

159. Chatzopoulos, D., Varma, A., and Irvine, R. L., Activated carbon adsorption and desorption of toluene in the aqueous-phase. AIChE J., 1993. 39(12): 2027-2041.

160. Isalski, W. H., Separation of Gases. Monographs on Cryogenics. Vol. 5. 1989, New York, NY: Oxford University Press.

161. Kohl, A. L. and Riesenfeld, F. C., Gas Purification. 4th ed. 1985, Houston, TX: Gulf Publishing Company.

162. Seader, J. D., Separation Process Principles. 1998, New York: Wiley.

163. Sirkar, K. K., Membrane separation technologies: Current developments. Chem. Eng. Commun., 1997. 157: 145-184.

164. Cussler, E. L., Diffusion: Mass Transfer in Fluid Systems. 2nd ed. 1997, Cambridge, UK: Cambridge University Press.

295

165. Herzog, H. J. The economics of CO2 separation and capture. in Second Dixy Lee Ray Memorial Symposium. 1999. Washington D.C.

166. Liu, Y. D., Zhang, L. Z., and Watanasiri, S., Representing vapor-liquid equilibrium for an aqueous MEA-CO2 system using the electrolyte nonrandom-two-liquid model. Ind. Eng. Chem. Res., 1999. 38(5): 2080-2090.

167. Supap, T., Idem, R., Veawab, A., Aroonwilas, A., Tontiwachwuthikul, P., Chakma, A., and Kybett, B. D., Kinetics of the oxidative degradation of aqueous monoethanolamine in a flue gas treating unit. Ind. Eng. Chem. Res., 2001. 40(16): 3445-3450.

168. Barnicki, S., Personal communication. 2003.

169. Lee, J. I., Otto, F. D., and Mather, A. E., Solubility of hydrogen sulfide and carbon dioxide in aqueous monoethanolamine solutions. Can. J. Chem. Eng., 1974. 52(6): 803-5.

296