Siloxane and Silane-Functionalized Polynorbornenes As Membranes for Passive Carbon Dioxide Separation
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University of Tennessee, Knoxville TRACE: Tennessee Research and Creative Exchange Masters Theses Graduate School 12-2015 Siloxane and Silane-functionalized Polynorbornenes as Membranes for Passive Carbon Dioxide Separation Eunice Koheun Hong University of Tennessee - Knoxville, [email protected] Follow this and additional works at: https://trace.tennessee.edu/utk_gradthes Part of the Environmental Chemistry Commons, Organic Chemistry Commons, and the Polymer Chemistry Commons Recommended Citation Hong, Eunice Koheun, "Siloxane and Silane-functionalized Polynorbornenes as Membranes for Passive Carbon Dioxide Separation. " Master's Thesis, University of Tennessee, 2015. https://trace.tennessee.edu/utk_gradthes/3585 This Thesis is brought to you for free and open access by the Graduate School at TRACE: Tennessee Research and Creative Exchange. It has been accepted for inclusion in Masters Theses by an authorized administrator of TRACE: Tennessee Research and Creative Exchange. For more information, please contact [email protected]. To the Graduate Council: I am submitting herewith a thesis written by Eunice Koheun Hong entitled "Siloxane and Silane- functionalized Polynorbornenes as Membranes for Passive Carbon Dioxide Separation." I have examined the final electronic copy of this thesis for form and content and recommend that it be accepted in partial fulfillment of the equirr ements for the degree of Master of Science, with a major in Chemistry. Brian K. Long, Major Professor We have read this thesis and recommend its acceptance: Alexei P. Sokolov, Ampofo K. Darko Accepted for the Council: Carolyn R. Hodges Vice Provost and Dean of the Graduate School (Original signatures are on file with official studentecor r ds.) Siloxane and Silane-functionalized Polynorbornenes as Membranes for Passive Carbon Dioxide Separation A Thesis Presented for the Master of Science Degree The University of Tennessee, Knoxville Eunice Koheun Hong December 2015 Copyright © 2015 by Eunice Koheun Hong All rights reserved. ii ACKNOWLEDGEMENTS To Brian, For giving me the opportunity to try something new and for allowing me to be part of the gang. To my lab cohorts, For making me laugh amidst the chaos and for helping me be better than I was. To T, For keeping me sane and for simply being the best. iii ABSTRACT In 2012, carbon dioxide (CO2) [carbon dioxide] accounted for approximately 82% 1 [percent] of all U.S greenhouse gas emissions. These excessive CO2 levels have been attributed to climate changes that have a range of negative effects on human health and welfare.1 In an effort to decrease these emissions, polymeric membranes consisting of silane- and siloxane-functionalized norbornene units have been targeted as a potential solution for the passive separation of CO2 from other non-greenhouse gases. These substituted norbornene-based polymers were synthesized via vinyl-addition polymerization. Through a series of catalyst trials, commercially available palladium and nickel catalysts were compared along with trans-[Ni(C6F5)2(SbPh3)2] [trans- bis(pentafluorophenyl)bis(triphenylstibine)nickel] to determine the catalytic activity for various silane- and siloxane-functionalized norbornene derivatives. It was observed that trans-[Ni(C6F5)2(SbPh3)2] overall had the highest activity for these types of monomers. Subsequently, free-standing films were formed from these functionalized norbornene- based polymers by utilization of a “dry/wet-phase inversion” technique. Through a collaboration with Oak Ridge National Laboratory, these novel membranes were analyzed and subsequently evaluated using Robeson Plots as a gauge of efficiency and real-world viability. iv TABLE OF CONTENTS Chapter 1: Introduction to Gas Separation Membranes................................................. 1 1.1: Introduction to carbon dioxide emissions and Clean Power Plan.............. 1 1.2: Current Industry Methods......................................................................... 2 1.3: Evaluation of Membrane Performance...................................................... 4 1.4: Issues in Existing Carbon Dioxide Purification Membranes.................. ... 7 1.5: Conclusion................................................................................................. 9 Chapter 2: Synthesis of Siloxane and Silane-functionalized Polynorbornenes......... 10 2.1: Introduction to Norbornene Vinyl-addition Polymerization.................... 10 2.2: Previous Research with Siloxane and Silane-functionalized Polynorbornenes.........................................................................................12 2.3: Traditional Vinyl-addition Polymerization Catalysts............................... 13 2.4: trans-[Ni(C6F5)2(SbPh3)2] ......................................................................... 14 2.5: Results and Discussion………………….....…………………………......15 2.6: Conclusion................................................................................................. 25 Chapter 3: Fabrication and Testing of Free-Standing Membranes ....................... ... 27 3.1: Formation of Membranes...........................................................................27 3.2: Membrane Analysis......................... ..........................................................28 3.3: Results and Discussion............................................................................. 30 v 3.4: Conclusion............................................................................................ .... 35 Chapter 4: General Conclusions.................................................................................37 References................................................................................................................. 40 Appendix....................................................................................................................43 Vita .............................................................................................................................53 vi LIST OF TABLES Table 1.1. CO2 Capture Technologies and Applications............................................... 4 Table 2.1. Catalyst Systems..........................................................................................16 Table 2.2. Endo:Exo Isomers.......................................................................................18 Table 2.3. Polymers......................................................................................................19 Table 3.1 Free-standing films CO2 permeability and selectivity values for P3-P8......................................................................................................33 Table A1. NB-PDMS Permeability and Selectivity Values..........................................46 Table A2. Spin-coated copolymers P1 and P2..............................................................47 vii LIST OF FIGURES Figure 1.1. Robeson Plots for a) CO2/CH4 and b) CO2/N2..................................................6 Figure 1.2. Post-polymerization functionalization of PIM-1's cyano group and their effects on CO2/N2 permeability/selectivity.........................................................8 Figure 2.1. Polymerization Methods of Norbornene..........................................................10 Figure 2.2. Common Metal Catalysts for Norbornene Polymerization...............................14 Figure 2.3. Percent Yields of P1-P3 in chlorobenzene and DCM.......................................21 Figure 2.4. Percent Yields of P1-P3 with Catalyst F...........................................................22 Figure 2.5. Percent Yields of P3-P5 in chlorobenzene and DCM.......................................24 Figure 2.6. Percent Yields of P3 and P6 in chlorobenzene and DCM.................................25 Figure 3.1. High-Vacuum Gas Permeation Instrument.......................................................29 Figure 3.2. Initial Results for Free-Standing Films P5-P11................................................33 Figure A.1. PDMS Polymer and NB-PDMS......................................................................46 Figure A.2. Initial Results for NB-PDMS Controls and Spin-coated Films of P12 and P13................................................................................................48 viii LIST OF ABBREVIATIONS AND SYMBOLS α.........................................alpha Å........................................angstrom AgBF4................................silver tetrafluoroborate AgSbF6..............................silver hexafluoroantimonate BrC6F5...............................bromopentafluorobenzene CO2....................................carbon dioxide DCM………......................dichloromethane (methylene chloride), solvent EtOH..................................ethanol, solvent Et2O...................................diethylether, solvent [NiBr2(dme)].....................nickel(II)bromide, dimethoxyethane adduct EPA...................................Environmental Protection Agency MeOH...............................methanol, solvent NB-TMS..........................5-trimethylsilylnorbornene N2......................................nitrogen PIM...................................polymer of intrinsic microporosity PDMS...............................polydimethylsiloxane SbPh3................................triphenylantimonate THF..................................tetrahydrofuran, solvent ix CHAPTER 1 Introduction to Gas Separation Membranes 1.1 Introduction to Carbon Dioxide Emissions and the Clean Power