General Predictive Syntheses of Cubic, Hexagonal, and Lamellar Silica and Titania Mesostructured Thin Films

Abstract

Well-ordered mesostructured silica and titania films were prepared using poly(ethylene oxide)−poly(propylene oxide)−poly(ethylene oxide) triblock copolymer species (Pluronic P123) as the structure-directing agents. By varying the volume ratio between the copolymer and inorganic components of the precursor solution, silica and titania thin films with cubic, 2D hexagonal, and lamellar mesostructures were prepared. The regions over which the three phases were obtained correspond well with those of the water−block copolymer binary phase diagram when considered in terms of the volume fraction of copolymer incorporated. In particular, a cubic mesostructure with crystalline TiO 2 (anatase) in the walls, stable to 400 °C, was synthesized.