Direct Deposition of Mesoscopically Assembled Dye-Doped Silica Films from Aqueous Solutions of Silicon Alkoxides

Silica films incorporating organic dyes, such as Rhodamine B and Disperse Red 1, were directly deposited on a substrate from aqueous solutions of phenyltriethoxysilane (PhTES). The organic dyes were homogeneously dispersed and firmly trapped in a silica matrix. The X-ray diffraction patterns indicated that the dye-doped films have a mesoscopically assembled structure. Since the period of the mesostructure, ca. 12 Å, was almost the same as the average distance between the dye molecules, the dye-doped films were suggested to be formed by assembling micelle-like clusters consisting of a monomer of the organic dyes surrounded with the hydrolyzed silica precursors. Thus, the monomers of the dyes were tightly captured in a three-dimensional cage of the silica network. Mesoscopically porous silica films were obtained by calcination of the deposited films.