An efficient route to mesoporous silica films with perpendicular nanochannels

Mesoporous silica films with cylindrical pores oriented normal to the substrate are prepared by selective deposition of silica within the poly(hydroxy styrene) domains of poly(alpha-methyl styrene-b-hydroxy styrene) template films using supercritical carbon dioxide as a delivery medium. Atomic force microscopy, electron microscopy, and grazing incidence small angle X-ray scattering (see figure) studies confirm the vertical alignment of the cylindrical pores.