POLYHIPEs MORPHOLOGY, SURFACE MODIFICATION AND TRANSPORT PROPERTIES by BORAN ZHAO Submitted in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Dissertation Advisers: Dr. Donald L. Feke and Dr. Ica Manas-Zloczower Department of Chemical and Biomolecular Engineering CASE WESTERN RESERVE UNIVERSITY January 2019 CASE WESTERN RESERVE UNIVERSITY SCHOOL OF GRADUATE STUDIES We hereby approve the thesis/dissertation of Boran Zhao candidate for the degree of Doctor of Philosophy *. Committee Chair Donald L. Feke Committee Members Ica Manas-Zloczower Jay Adin Mann Jr. Uziel Landau David Schiraldi Date of Defense September 18th, 2018 *We also certify that written approval has been obtained for any proprietary material contained therein. DEDICATION To faith in truth, who carries me in seeking answers; To faith in consciousness, who drives me in the right directions; To my beloved family, who are the source of my happiness; To myself, for not yielding in pressure and not being satisfied in absorbing knowledge. i TABLE OF CONTENTS Dedication ............................................................................................................................ i Table of Contents ................................................................................................................ ii List of Tables ................................................................................................................... viii List of Figures .................................................................................................................... ix Acknowledgments............................................................................................................ xxi Abstract ................................................................................................................................1 Chapter 1 Introduction ..................................................................................................3 1.1 The Significance of Porous Materials .............................................................3 1.2 Porous Materials Classification and Processing Methods ...............................4 1.2.1 Metal porous materials .....................................................................4 1.2.2 Porous ceramics ...............................................................................5 1.2.3 Polymeric porous materials..............................................................5 1.3 Dissertation Outline .........................................................................................9 Chapter 2 Emulsion Preparation and the Corresponding Effects on Poly(HIPE) Foam Morphological and Mechanical Properties ..........................................11 2.1 Synopsis ........................................................................................................11 2.2 Introduction ...................................................................................................11 2.2.1 Droplet breakup mechanism ..........................................................13 2.2.2 Emulsification methods .................................................................17 2.2.3 General emulsion stability .............................................................18 2.2.4 Causes for emulsion instability ......................................................18 ii 2.2.5 High internal phase emulsions .......................................................20 2.2.6 Curing of high internal phase emulsions .......................................24 2.2.7 Interfacial tension kinetics .............................................................26 2.3 Experimental ..................................................................................................29 2.3.1 Materials ........................................................................................29 2.3.2 Mixing procedures: tuning HIPE morphology ..............................29 2.3.3 Interfacial tension kinetics using Wilhelmy Plate method ............32 2.3.4 HIPE and polyHIPE morphology analysis ....................................33 2.3.5 Chemorheology study ....................................................................34 2.3.6 Mechanical properties ....................................................................35 2.3.7 Thermal stability analysis ..............................................................35 2.4 Results and Discussion ..................................................................................35 2.4.1 The effect of propeller mixer setup on emulsion morphology ........................................................................................................35 2.4.2 The effect of syringe mixer setup on emulsion morphology .........41 2.4.3 Emulsion morphology under centrifugal force ..............................50 2.4.4 Interfacial tension (IFT) dynamics .................................................58 2.5 Conclusions ...................................................................................................62 Chapter 3 Morphological and Surface Effects on PolyHIPE Foam Transport Properties: Permeability and Spontaneous Imbibition .......................................................63 3.1 Synopsis .........................................................................................................63 3.2 Introduction ...................................................................................................64 iii 3.2.1 Flow in porous media.....................................................................64 3.2.2 Substrate roughness effect .............................................................67 3.2.3 Roughness effect on micro channels ..............................................68 3.2.4 Wetting ...........................................................................................69 3.2.5 Fluid transport in polyHIPE foams ................................................73 3.3 Experimental .................................................................................................75 3.3.1 Materials ........................................................................................75 3.3.2 Emulsion preparation .....................................................................76 3.3.3 Foam morphology ..........................................................................76 3.3.4 Relative foam density ....................................................................79 3.3.5 Foam mechanical properties ..........................................................79 3.3.6 Permeability measurement .............................................................80 3.3.7 Spontaneous imbibition measurement ...........................................82 3.3.8 Surfactant coating ..........................................................................83 3.4 Results and Discussion ..................................................................................84 3.4.1 Variation of foam morphology ......................................................84 3.4.2 Foams mechanical properties .........................................................85 3.4.3 Darcy’s flow through polyHIPE foams .........................................88 3.4.4 Spontaneous imbibition in polyHIPEs ...........................................90 3.4.5 Silicon oil imbibition .....................................................................92 3.4.6 Partial wetting-water imbibition in surfactant coated foams .........97 3.5 Conclusions .................................................................................................107 iv Chapter 4 Surface Modification of Polyhipe Foams ................................................108 4.1 Synopsis ......................................................................................................108 4.2 Introduction .................................................................................................108 4.3 Experimental ...............................................................................................110 4.3.1 Foam preparation .........................................................................110 4.3.2 Cellulose nanocrystals (CNC) preparation ..................................110 4.3.3 CNC dispersion preparation .........................................................111 4.3.4 Graphene oxide (GO) preparation ...............................................111 4.3.5 Coating process ............................................................................112 4.3.5.1PolyHIPE foam coated with CNC ....................................112 4.3.5.2PolyHIPE foam coated with GO and achieving electrical conductivity ......................................................112 4.4 Results and Discussion ...............................................................................113 4.4.1 CNC-coated polyHIPE nanocomposite .......................................113 4.4.2 Conductive polyHIPE via GO coating .........................................120 4.5 Conclusions .................................................................................................133 Chapter 5 PolyHIPE Foams as Oil Sorbent: Volume Expansion, W/O Emulsion Selectivity and Volumetric Capacity ...............................................................135 5.1 Synopsis ......................................................................................................135 5.2 Introduction .................................................................................................136