Preparation of Transparent Silica-Surfactant Nanocomposite Films with Controlled Microstructures

Novel silica-alkyltrimethylammonium (with the alkyl groups of decyl, dodecyl, tetradecyl, hexadecyl, and octadecyl) bromide nanocomposite films were synthesized by coating the precursor solutions containing prehydrolyzed tetramethoxysilane and alkyltrimethylammonium bromide. The composites are thought to be composed of aggregates of alkyltrimethylammonium bromides and thin silica layers. The d values of the products varied depending on the relative ratios of tetramethoxysilane and surfactants, suggesting that the microstructures of the products can be controlled by simply changing the compositions. Since the present composites are obtained as transparent films, they have potential applicability as a new class of functional materials, especially for photofunctional purposes.