Soft templated mesoporous SiC from polycarbosilane grafted onto triblock copolymers

Abstract

Mesoporous silicon carbide (SiC) presenting very large specific surface area was elaborated following an original soft-templating approach based on polymeric precursors. The polystyrene units of a poly(styrene-block-butadiene-block-styrene) triblock copolymer are used as a templating agent, while a polycarbosilane preceramic polymer is employed as SiC precursor. Thanks to the self-organization of polycarbosilane around PS blocks in liquid medium, and to the subsequent elimination of the copolymer during the polycarbosilane conversion into SiC, a mesoporous SiC can be formed. High specific surface areas of more than 400m2g−1 are measured on the final SiC, opening the doors to the viable production of SiC of controlled porosity.