Date of Completion
Field of Study
Doctor of Philosophy
Graphene, with its outstanding electrical, mechanical, and thermal properties, has been the focus of much attention since it was the topic of the 2010 Nobel Prize.
Current methods to produce graphene include chemical vapor deposition (CVD) and epitaxial growth, as well as micromechanical, oxidation-reduction, and solvent/surfactant aided exfoliation of graphite. All of these methods, however, have serious limitations. A common theme for all of these procedures is that the insolubility of graphene in virtually all solvents is an obstacle to be overcome. In this dissertation, we present a method for the production of pristine graphene (graphene that has not been chemically modified) that instead relies on the insolubility of graphene. In the interface trapping method, graphene is seen to act as a two dimensional surfactant, where it is trapped at the interface of oil and water, and lowers the interfacial energy of the system.
By utilizing this technique, we are able to produce conductive, transparent films of few layer graphene sheets on hydrophilic substrates. These can then be transferred to virtually any substrate and have the potential to be used in applications such as solar cells and flexible displays. Using the same approach, pristine graphene and graphite may be infused into fabrics to impart conductivity and increased strength for use in smart textiles. By altering the initial method to produce films, graphene stabilized emulsions are formed. If a monomer is used in place of the original inert oil, the emulsions may be used to template the creation of strong, lightweight, conductive composite materials. Furthermore, by varying the monomer used, flexible composite materials may be formed that are conductive and chemically sensing. These may find potential applications in energy storage, filtration, sensing, and construction materials.
Woltornist, Steven J., "Pristine Graphene as a Two-Dimensional Surfactant" (2016). Doctoral Dissertations. 1032.