Direct deposition of silica films containing organic groups and dyes from silicon alkoxide solutions

A new direct-deposition process for silica thin films was developed using silicon alkoxide solutions. Silica thin films incorporating organic groups, such as methyl (CH₃) and phenyl (C₆H₅) groups, were deposited on substrates from aqueous and ethanol solutions of organyltrialkoxysilane. Silica films without organic groups were also formed using ethanol solution of tetraalkoxysilane with aqueous ammonia. Composition of the deposited silica films were influenced by temperature and pH of the solutions and the starting alkoxides. From aqueous solutions containing organyltrialkoxysilane and organic dyes, such as Disperse Red 1 and Rhodamine B, silica films including the dyes were directly prepared on substrates. The composition of silica-organic hybrid films prepared by the deposition method was successfully controlled by selecting the deposition condition and the starting materials.