Silicon oxycarbide glasses

The application of sol-gel techniques to glass synthesis has significantly advanced the development and characterization of silicon oxycarbide glasses. In this approach, alkyl-substituted silicon alkoxides, which are molecular precursors containing oxygen and carbon functionalities on the Si, can be hydrolyzed and condensed without decomposition or loss of the carbon functional group. A low-temperature heat-treatment (<1000 °C) of the gel creates a glassy silicate material whose molecular structure consists of an oxygen/carbon anionic network. Also, there is always a blackening of the material due to elemental carbon, which forms during pyrolysis and densification of the gel.