Theses and Dissertations Collection

While the fundamental properties and potential applications of GUITAR (pseudo-Graphite from the University of Idaho Thermalized Asphalt Reaction) have been explored over the past decade, the underlying structural features responsible for its unique electrochemical behavior have yet to be determined. Given the nanocrystalline grain size, the basal/edge orientation, and the wavy surface topography, the most likely structural components responsible for GUITAR's unique basal plane are grain boundary defects. Grain boundaries are found at the interface between different graphene crystallite domains and are typically composed of 5, 7, and 8 membered rings. Grain boundary defects are predicted to have enhanced reactivity towards functionalization due to increased molecular strain. This is significant because a typical graphite basal plane is chemically inert, and a vast majority of functionalization reactions are selective for edge planes and step defects. The ability to modify the surface functional groups on an electrode allows you to tune the physical, chemical, and electrochemical properties to better serve a wide array of applications. This dissertation will describe three major studies involving the modification of GUITAR’s surface functional groups. The first study involves the electrochemical amination and subsequent carbodiimide coupling of 2,5-dihydroxybenzoic acid to the basal plane of GUITAR (chapter 2). The next study utilizes mild anodic oxidation to saturate the basal plane of GUITAR with oxygen-containing functional groups (Ox-GUITAR), resulting in superhydrophilic properties and strong resistance to fouling (chapter 3). The final study involves the application of Ox-GUITAR as a high stability sensor for free chlorine (chapter 4). These studies display how the surface functionalization of GUITAR can tailor the physical and electrochemical properties toward a wide range of applications.