A New Process for Silica Coating

Silica film was deposited on the surface of soda lime silicate glass by immersing it in hydrofluosilicic acid solution supersaturated with silica gel at low temperature. The composition and the structure of these films were evaluated using ESCA, IRRS, fluoric acid etching test, and sodium leaching test, and they were compared with those of various silica films prepared by other methods. The results showed that these films made at low temperature had a dense structure and a great alkali barrier effect. By heat‐treatment, the structure of this film became denser, getting close to that of fused silica. It was also found that the degree of supersaturation and the solution temperature had a great influence on the deposition rate.