Organic-Inorganic Hybrid Materials 4: NMR Study of the Poly(imide-silica) Hybrids

Abstract

The microstructure of the poly(imide-silica) hybrid materials 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 Q 2, Q 3 and Q 4 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 restricted by silica than by imide. The spin-lattice relaxation time in rotating frame (T H 1p ) of hybrids indicated that the 1H spin diffusion between imide and siloxane units were on a nanometer scale.