Silicon-Oxycarbide Gels and Glasses

点击翻译按钮获取中文摘要

Synthesis of silicon oxycarbide gels and glasses is achieved through the hydrolysis/condensation of alkyl-substituted alkoxysilanes. It forms a gel whose subsequent heat-treatment in an inert atmosphere creates an x-ray amorphous glass that contains both Si-O and Si-C bonds. The glass is often black due to the additional presence of a highly dispersed form of polyaromatic, pyrolytic, and/or amorphous carbon. A primary objective of this project is to characterize, in detail, the ternary Si-O-C system, and especially to determine the molecular structure of the excess carbon, its relationship to the oxycarbide network, and its effect on the thermochemical stability of the glass. NMR, Raman spectroscopy, and TEM will be used to characterize the glasses. %%%% Oxycarbide glasses exhibit enhanced properties. Characterization of the glass structure is essential for future exploitation of these unique glasses. This program is expected to yield valuable information and possibly to provide a basis for developing new reinforced composite materials, by sol-gel methods.