Preparation Of Silicon Carbide Nanofibrils From Vapor Grown Carbon Nanotubes

Abstract

ABSTRACTSiC nanofibrils are of interest for their potential applications, particularly for the development of nanostructured ceramic (or metal) matrix composites. Methods of production of SiC nanofibrils in bulk quantity are essential for realization of these applications. We have prepared SiC nanofibrils with average diameters of 15 nm by direct reaction of carbon nanotubes with vapor phase SiO. The carbon nanotubes were prepared catalytically by decomposition of hydrocarbons in our commercial process; they are characterized by having uniform diameter of ∼10 nm and multiple graphitic carbon layers arranged concentrically around the tube axis. Total conversion of the carbon nanotubes to SiC nanofibrils was easily achieved; the resulting SiC nanofibrils were highly crystallized β-SiC, essentially free of SiC particles. The reaction between carbon nanotubes and SiO vapor was a pseudo-topotactic transformation since the macroscopic textures of the starting carbon nanotubes remained almost unchanged in the product. This synthetic approach utilizes high quality carbon nanotubes of high uniformity which are available on a commercial scale; thus applications of SiC nanofibrils in matrix composites on a commercial scale can be envisioned.