Morphological Studies on CNT Reinforced SiC/SiOC Composites

Abstract

Carbon nanotubes (CNTs) have been grown on commercially available silicon carbide (SiC) fabric by the catalytic chemical vapour deposition (CCVD) technique. These CNT coated SiC fabrics were used to develop Silicon Carbide–Carbon Nanotube–Silicon oxy Carbide matrix composites (SiC/CNTs/SiOC) by sol gel technique. Silicon oxy Carbide refers to carbon containing silicates wherein oxygen and carbon atoms share bonds with silicon in the amorphous network structure. In this approach, alkyl-substituted silicon alkoxides, which are molecular precursors containing oxygen and carbon functionalities on the silicon, are hydrolyzed and condensed in the presence of sucrose, which provides excess of carbon to bond into the silicon alkoxide network during hydrolysis. A low-temperature (1000 °C) heat-treatment of the gel creates a glassy silicate material whose molecular structure consists of an oxygen/carbon anionic network. The microstructures of these hybrid materials and their composites have been studied using scanning electron microscope (SEM), transmission electron microscope (TEM) and Raman spectroscope.