- Mesoporous films with cubic and hexagonal (MCM-48, 41, respectively) symmetries were synthesized at the oil–water interface. The silica precursors were segregated between oil and water phases. The film's formation was studied with small angle X-ray scattering, Brewster angle microscopy, light microscopy techniques and atomic force microscopy. A phase map depicting the aging and heating times required for the cubic phase formation was constructed. Differences in roughness between the silica–oil and silica–water interfaces were analyzed with AFM. It is speculated that the differences are indicative of the mechanism of film formation and growth.