Date of Graduation
Statler College of Engineering and Mineral Resources
Chemical and Biomedical Engineering
C. D. Stinespring.
Buckled graphene produced by the halogen based etching of 6H-SiC provides a new route for the functionalization of the graphene surface. This surface provides an important new stepping off point in the development of molecular electronics and sensors. While the graphene surface is relatively inert, the fluorinated defect sites inherent in the buckled graphene surface yield an excellent location for chemical reactions such as nucleophilic substitution. This thesis shows the utility of the fluorinated defect sites through the well characterized diazonium reaction.;Buckled graphene films were prepared on silicon carbide substrates using inductively coupled plasma and reactive ion etching, and annealed at 1000° C to coalesce the BG. The films were reacted with benzene, nitrobenzene, acetonitrile, or a nitrophenyl diazonium salt solution. The diazonium salt was chosen due to its known reaction with graphene produced by other methods. Consequently, reaction of the diazonium with buckled graphene would provide a basis for comparing the reactivity of the surface with these other forums of graphene. The interactions of buckled graphene with the other species were investigated as they represent either constituent parts of the diazonium salt or the solvent. The reacted surfaces were analyzed by X-ray photoelectron spectroscopy, which reveals changes in the surface chemical state due to the functionalization of the buckled graphene by each species.;Each reaction yielded significant pi-pi bonding, while the diazonium salt reaction produced additional covalently bonded phenyl groups on the buckled graphene surface. The covalent reaction site was shown to be the surface fluorinated defect site. This observation illustrates the utility of the buckled graphene surface in the functionalization of graphene. Moreover, it provides additional confirmation of the nature of the buckled graphene surface.
Nelson, Timothy C., "Functionalization of Buckled Graphene" (2011). Graduate Theses, Dissertations, and Problem Reports. 2223.