This award is made in the Organic Dynamics Program is support of Dr. J. Kerry Thomas' continuing research on radiation-induced reactions in organized and constrained media. Reactive intermediates will be generated by photochemical or radiation excitation of pyrene or other adsorbed species trapped in zeolites, silica, or a host of polymers such as polystyrene, polyethylene, polymethyl methacrylate, polyacrylonitrile, polyvinyl chloride and polyvinyl alcohol. Depending on the system selected, electrons (e-), holes (h+), cations, cation-radicals, anions, and/or free radicals will be generated, and their reactivity, motion, and energy-transfer properties monitored by their fluorescence, phosphorescence, and absorption spectra. These techniques will reveal unique trapping sites for ions in solid media and will monitor migration of energy and charge in excited polymers, to soluble probe molecules. The behavior of reactive intermediates in constrained media is relevant to heterogeneous catalysis in the case of zeolites and silica, and to understanding the mechanism of light and radiation- induced degradation of polymers. The action of high-energy radiation on polymers relates to the use of polymers in microelectronics and the use of radiation processing in nanolithography.
