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Processing 2D Nanomaterials: Study of Colloidal and Chemical Stability of Boron Nitride and Ti3c2tx Nanosheets

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Processing 2D Nanomaterials: Study of Colloidal and Chemical Stability of Boron Nitride and Ti3c2tx Nanosheets PROCESSING 2D NANOMATERIALS: STUDY OF COLLOIDAL AND CHEMICAL STABILITY OF BORON NITRIDE AND TI3C2TX NANOSHEETS A Dissertation by TOUSEEF HABIB Submitted to the Office of Graduate and Professional Studies of Texas A&M University in partial fulfillment of the requirements of the degree of DOCTOR OF PHILOSOPHY Chair of Committee, Micah J. Green Committee Members, Jodie L. Lutkenhaus Miladin Radovic Mustafa Akbulut Head of Department, M. Nazmul Karim May 2019 Major Subject: Chemical Engineering Copyright 2019 Touseef Habib ABSTRACT Two-dimensional (2D) nanomaterials have been hotly investigated since the identification of graphene in 2004. With so much research focus it has been difficult to translate promising laboratory results to commercial success. The main reason for this is the processing of such nanomaterials. Processing at a nanoscale is challenging because the materials at that scale either aggregate to their parent structure or chemically degrade, rendering them useless. In this work, liquid processing advancement of two novel nanosheets are presented; boron nitride nanosheets (BNNSs) and Ti3C2Tx MXenes. BNNSs are difficult to process at the nanoscale because they tend to aggregate. We have demonstrated the viability of co-solvents in processing BNNSs to obtain high yields while still maintaining a high quality BNNSs. Ti3C2Tx MXenes on the other hand are easier to process but they oxidize. The chemical degradation was examined various media and suggestions made to store Ti3C2Tx MXenes in solid media to decrease the rate of oxidation. Additionally, we demonstrated a never-before-seen property of Ti3C2Tx MXenes: their propensity to rapidly heat under radio frequency fields. We explored how polymer/ Ti3C2Tx composite film architecture and composition affect both conductivity and RF responsiveness. This new property can be exploited for various RF-based applications where localized heating is desired. ii ACKNOWLEDGEMENTS Majority of the credit for this PhD goes to my parents, they always pushed me to go further and never settle. With their unconditional love, support, and belief in me (even when I did not) inspired me to carry on with my studies. To my brothers, thank you for the initial push and for the constant support over the last five years; you both always kept my spirits up. I am grateful to my research group members, past and present. Fahmida Irin, Dorsa Parviz, Yueyi Xu, and Brandon Sweeney. They welcomed me in the group with open arms. To Smit Shah, Xiofei Zhao, Nutan Patil, Muhammad Anas, and Wanmei Sun; thank you for your contributions, I could not have finished my work without your help and backing. I also want to thank Thomas Achee and Eliza Price, the wondergrads who labored for me in the laboratory and helped me get my experiments done. I also want to acknowledge Pritishma Lakhe, Martin Pospisil, Kai Morikawa, Joseph Gerringer, Saerom Yu, Morgan Plummer, and the rest of the Green group for their input and contributions. To Dr. Miladin Radovic and Dr. Jodie Lutkenhaus, thank you. As committee members and collaborators, your ideas and feedback has helped me immensely. Thank you Dr. Mustafa Akbulut, I appreciated you input during the committee meetings. I also want to acknowledge Hyosung An, Evan Prehn, and the other members of the Radovic and Lutkenhaus research groups; it was exciting collaborating with you guys. I am eternally grateful to my advisor Dr. Micah Green. Despite being burdened with the grueling schedule of academia, he always made time for his students. He was instrumental in my growth as a professional and as a researcher. Always leading by example, he set a high standard for what it means to be a scientist and a family man. I want to thank Allah, The Creator of all. None of this would be possible without him. “O my Lord, increase me in knowledge” Quran, 20:114. iii CONTRIBUTORS AND FUNDING SOURCES This work was supervised by a committee consisting of Professor Micah Green (advisor), Jodie Lutkenhaus, and Mustafa Akbulut from the Department of Chemical Engineering and Professor Miladin Radovic from the Department of Material Science. Some data from Chapter 2 were provided by Professor Rajesh Khare from Texas Tech University’s Department of Chemical Engineering. All other work was completed by the student independently. My research was supported by Artie McFerrin Department of Chemical Engineering with their graduate student assistantship. Funding for this work was provided by the National Science Foundation under CAREER award CMMI-1253085 as well as a 2014 DuPont Young Faculty Award. Additional funding was provided by the U.S. National Science Foundation (Grant CMMI- 1760859) and TAMU Energy institute. iv TABLE OF CONTENTS Page ABSTRACT ................................................................................................................................................ ii ACKNOWLEDGEMENTS ..................................................................................................................... iii CONTRIBUTORS AND FUNDING SOURCES ................................................................................ iv TABLE OF CONTENTS .......................................................................................................................... v LIST OF FIGURES ................................................................................................................................. vii LIST OF TABLES .................................................................................................................................... xi CHAPTER 1 – INTRODUCTION .......................................................................................................... 1 Boron nitride nanosheets (BNNSs) ............................................................................................. 1 Synthesis & Processing ........................................................................................................... 2 Applications ............................................................................................................................. 5 Challenges ............................................................................................................................... 9 Ti3C2Tx MXene nanosheets ......................................................................................................... 9 Synthesis & Processing ......................................................................................................... 10 Applications ........................................................................................................................... 12 Challenges ............................................................................................................................. 20 CHAPTER 2 – COSOLVENTS AS LIQUID SURFACTANTS FOR BORON NITRIDE NANOSHEET (BNNS) DISPERSIONS .............................................................................................. 22 Summary ................................................................................................................................... 22 Introduction ............................................................................................................................... 22 Materials & Methods ................................................................................................................. 24 Results & Discussion ................................................................................................................ 28 Conclusion ................................................................................................................................. 41 CHAPTER 3 – OXIDATION STABILITY OF TI3C2TX MXENE NANOSHEETS IN SOLVENTS AND COMPOSITE FILMS ............................................................................................ 42 v Summary ................................................................................................................................... 42 Introduction ............................................................................................................................... 42 Materials & Methods ................................................................................................................. 44 Results & Discussion ................................................................................................................ 47 Conclusion ................................................................................................................................. 61 CHAPTER 4 – TI3C2TX MXENE/POLYMER COMPOSITES HEAT IN RESPONSE TO RADIO FREQUENCY (RF) FIELDS ........................................................................................... 62 Summary ................................................................................................................................... 62 Introduction ............................................................................................................................... 62 Materials & Methods ................................................................................................................. 63 Results & discussion ................................................................................................................. 66 Conclusion ................................................................................................................................. 77 CHAPTER 5 – CONCLUSION ............................................................................................................
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