Vapor phase synthesis of mesoporous silica thin films with a 3D pore structure

Ordered mesoporous silica thin films were prepared using non-ionic alkyl poly(oxyethylene) surfactants (Brij56: C18EO10) by a vapor phase method. First, a Brij56/H2SO4 composite was deposited on a silicon substrate by spin-coating. The Brij56 film was treated with a tetraethoxysilane (TEOS) and hydrochloric acid (HCl) vapors in a closed vessel. The TEOS and HCl vapors were infiltrated into the film, resulted in a formation of the silica network. Results of a grazing angle of incidence small angle X-ray scattering (GISAXS) show that the films have an ordered structure with an Fmmm symmetry. From an Field emission scanning electron microscope (FESEM) observations, the film has a 3D pore structure.