ISSN 0004-881X

Growth of SiC Whiskers by Carbothermal Reduction of Mesoporous Silica-Carbon Composites Infiltrated With SiC Nuclei

by Kun Wang ¹, Yi-Bing Cheng^1*, Huanting Wang ²

1) Department of Materials Engineering, Monash University, Clayton, Victoria 3800, Australia
2) Department of Chemical Engineering, Monash University, Clayton, Victoria 3800, Australia

Abstract

Mesoporous C-SiO₂ nanocomposite with a low C/SiO₂ molar ratio was infiltrated with polycarbosilane (PCS) which is a preceramic precursor for silicon carbide. Different silicon carbide nanostructures were synthesized by carbothermal reduction of mesoporous C-SiO₂ nanocomposites via different heat treatments. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption-desorption analysis were used to characterize C-SiO₂ nanocomposites and SiC products. SiC was not formed in the mesoporous C-SiO₂ nanocomposites without PCS at 1450 degC. However, when it was infiltrated with PCS to allow a conversion of PCS into SiC nuclei in the mesopores during the heat treatment, highly crystalline SiC nanofibers and nanoparticles were produced.

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