Preparation of silica films by means of sol-gel process catalyzed by alkali

Catalyzed by NaF and NH3·H2O, silica films were prepared with the tetraethyl orthosilicate (TEOS) sol-gel. The effects of the category, concentration and addition amount of catalyst, as well as of the reaction temperature on the kinetics of hydrolization, polymerization and gelatinization of TEOS were investigated, and the surface morphology of the prepared silica films observed. It was found that the gelatinization time could be considerably shortened and a cellular silica film was formed by adding the catalyst and increasing reaction temperature.