Mapping of motional heterogeneity in organic-Inorganic nanocomposite gels

Abstract

Organic-inorganic nanocomposite gels comprising poly(ethyleneoxide) chains grafted between silica particles have been studied by electron paramagnetic and nuclear magnetic resonances. Motional heterogeneity has been investigated as a function of gelation and drying by paramagnetic probes dissolved in the organic phase or grafted onto the inorganic nodes. The organic phase exhibits marked variations in dynamic behavior with the liquid-like mobility of the polymer chains strongly hindered at the silica nodes. The conclusions of the EPR study are confirmed by liquid- and solid-state carbon-13 NMR measurements. © 1996 John Wiley & Sons, Inc.