Direct Preparation of High Surface Area Mesoporous SiC-Based Ceramic by Pyrolysis of a Self-Assembled Polycarbosilane-<i>block</i>-Polystyrene Diblock Copolymer

Abstract

Direct pyrolysis of a self-assembled inorganic−organic block copolymer can be a promising route for fabricating the ordered ceramic nanostructures based on the achievements of organic−organic block copolymers. Here we report the synthesis of a novel polycarbosilane-block-polystyrene diblock copolymer by ring-opening living anionic polymerization in a THF and n-hexane solvent system at −48 °C. The resulting block copolymer revealed phase-separation behavior in the nanoscale to form a self-assembled nanostructure that was converted to a mesoporous ceramic phase after heating at 800 °C. The pyrolyzed ceramic product exhibited well-ordered mesoporous SiC-based ceramic structures with a high BET surface area of 1325 m2 g−1 and an average mesopore size of 7.8 nm containing a large amount of micropores.