Preparation and characterization of structurally stable hexagonal and cubic mesoporous silica thin films

Transparent mesostructured silica-surfactant composite films were prepared by spin coating on silicon wafers at room temperature. A cumulative heating procedure that evaporates excess solvents and decomposes surfactants produced structurally stable mesoporous silica films. The X-ray diffraction patterns of the films indicate that both hexagonal and cubic mesoporous silica films can be formed by varying the surfactant to silicon mole ratio. The hexagonal and cubic ordered structures of the calcined mesoporous silica films were confirmed by TEM. Compared with hexagonal mesoporous silica films, the cubic mesoporous silica films had lower refractive index and higher BET surface area.