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Abstract
The microstructure of the polyvinylimidazole-silica hybrids (PVI-SiO2) containing various proportions of silica was examined by high resolution solid-state 29Si and 13C nuclear magnetic resonance spectroscopy. The 29Si-1H cross-polarization (CP) process revealed that the Q3 and Q4 species had different CP efficiency. Moreover, the time constant for the energy exchange between 1H and 29Si spin systems (T SiH) for the siloxane units was less dependent on the silica content, and that was in the range of 2.0 to 4.0 ms. The spin-lattice relaxation time in rotating frame (T H 1p) of hybrids suggested that the 1H spin-diffusion between imidazole and siloxane units were on a nanometer scale estimated by spin-diffusion path length.