Mesoporous silica thin films produced by calcination in oxygen plasma

A self-assembling amphiphilic triblock copolymer was utilized as template or structure-directing agent to apply mesoporous silica thin films on silicon by spin casting of an aqueous acidic sol–gel solution. Hexagonally packed mesoporous structures could be prepared, as indicated by X-ray diffraction analysis. Calcination in oxygen plasma was investigated as a possible method to hollow the pores. The resulting coatings were compared to those obtained through thermo- and photocalcination (selective ultraviolet irradiation), which is also a method recently developed in our group. Once the conditions were optimized, the oxygen plasma treatment proved to be a valid method to remove the organic template. Nevertheless, this methodology is comparatively more aggressive than photocalcination, resulting in flawed coatings.