Preparation and Characterization of the Transparent Hybrids of Silicone Epoxy Resin and Titanium Dioxide Nanoparticles via Sol-Gel Reactions

In order to prepare transparent hybrid films of high refractive index, nanoparticles of TiO2 were prepared and dispersed in a silicone epoxy (SE) resin synthesized from diphenyl silane diol and [2-(3,4-epoxycyclohexyl)ethyl] trimethoxysilane by so gel reactions. It was found that amorphous TiO2 nanoparticles of about 5 nm modified with hexahydro-4-methyl phthalic anhydride [HMPA] were dispersed in the SE resin without agglomerations. The refractive index of the hybrids increased linearly with increasing the TiO2 contents. The hybrid containing 30 wt% of the TiO2 particles showed, light transmittance of 94% at 450 nm and refractive index of 1.63. The fine dispersion of the TiO2 nanoparticles was attributable to the sol gel reactions between the SE resin and TiO2 nanoparticles and the modification of the TiO2 particles with HMPA.