Synthesis and Characterization of Novel Non-Oxide Sol-Gel Derived Mesoporous Amorphous Si-C-N Membranes

Abstract

A novel sol-gel-derived preceramic polymer, namely poly(organosilyl)carbodiimide, was synthesized for fabrication of thermally stable amorphous Si-C-N membranes. The gelation process as well as the viscosity of the poly(organosilyl)carbodiimide was adjusted for spin coating by reacting a mixture of alkyl and dialkyl chlorosilane monomers with bis(trimethylsilyl)carbodiimide. The polymeric precursor film was successfully fabricated on a porous substrate by solvent-free spin coating, subsequently converted into a mesoporous amorphous Si-C-N thin film by pyrolysis at 1000°C in Ar. SEM observation as well as N₂ sorption isotherm analysis exhibited the formation of meso-pore channels within the amorphous thin layer. These results indicate that the novel poly(organosilyl)carbodiimide developed in this study is suitable for fabricating meso-porous amorphous membranes in the ternary Si-C-N system and with high thermal and chemical stability.