Date of Award
Master of Arts
Dr. Donald R. Schreiber
Dr. John Chateauneuf
Masters Thesis-Open Access
A series of photochemically modified diamond surfaces were prepared. Surface functional groups added included, chlorine, bromine, methoxy, amine, methylamine, dimethylarnine and trimethylammonium chloride. Photochemically chlorinated and brominated diamond surfaces were used as synthetic intermediates. The modified diamond surfaces were characterized by Diffuse Reflectance Infrared Spectroscopy (DRIFT) and X-ray Photoelectron Spectroscopy (XPS).
The study was mainly focused on understanding the kinetic processes and reaction mechanism of modified surfaces. The observed rate constants for surface hydrogen loss and HCl (g) evolution were found to be identical. Similar rate constants were observed for amine substitution and consumption of ammonia.
The study of action spectra indicated that rate of photoreaction for halogenation was dependent on excitation wavelength. Amine substitution reaction was found to be coincident with a charge-transfer complex intermediate.
It was found that the halogenation of hydrogen-substituted diamond proceeds by photo-induced free radical reaction. Amines and alkoxy substitution was found to proceed by a photo-induced electron transfer mechanism.
Farooq, Humera, "Surface Modification of Diamond and Determination of Kinetics and Mechanism of Modification Reactions" (2001). Masters Theses. 4339.