Preparation of mesoporous silica films on a glass slide: Surfactant template removal by solvent extraction

Mesoporous silica films have been deposited on glass slides by the dip-coating method. Solvent extraction was used to completely remove the structure-directing surfactant with a carefully selected dilute HCl/EtOH solution, which was confirmed by Fourier-Transform infrared spectroscopy (FT-IR), and the films' ordered mesostructure was maintained. The weak bonding between template ions and inorganic species of thin film materials also resulted in the complete extraction of surfactant template with the ethanol solution. Small-angle X-ray diffraction (SAXRD) patterns and transmission electron microscope (TEM) images indicated that as-deposited and extracted films had a periodic hexagonal structure with the channels parallel to the substrate surface. The N₂ adsorption and desorption isotherms also showed that the film was a typical mesoporous material with pore channel size of about 2.4 nm.