Preparation of ordered mesoporous SiC from preceramic polymer templated by nanoporous silica

Highly ordered mesoporous SiC materials were prepared by infiltrating viscous liquid preceramic polymer, allylhydridopolycarbosilane, into two types of surface modified nanoporous silica templates: mesoporous silica SBA-15 and mesocellular siliceous foam. The silica templates were subsequently etched off after pyrolysis at 1000 degrees C under nitrogen atmosphere with the resultant formation of ordered mesoporous structures. The mesoporous SiC materials, synthesized from both types of templates possessed high Brunauer-Emmett-Teller (BET) surface areas in the range of 250-260 m(2)/g with pore sizes of 3.4-3.6 nm. The ordered structures of mesoporous SiC were exact inverse replicas of their respective silica templates, as characterized by small angle X-ray diffraction (XRD), transmission electron microscope (TEM) images, and the adsorption-desorption isotherm of nitrogen.