Sol-gel processing of carbidic glasses

摘要

Carbon incorporation into the silicate networkresults in the formation of rigid carbidic glasses with improvedphysical, mechanical and thermal properties. This generated greatinterest in the development of these heteroatom structuredmaterials through different processing routes. In the presentstudies, sol-gel processing has been used to prepare silicon basedglasses, especially oxycarbides through organic-inorganic hybridgels by hydrolysis-condensation reactions in silicon alkoxides, 1,4-butanediol and furfuryl alcohol with an aim to introduce Si-Clinkages in the precursors at sol level. The incorporation of theselinkages has been studied using IR and NMR spectroscopy. Thesebonds, so introduced, are maintained throughout the processing,especially during pyrolysis to high temperatures. In FFA-TEOSsystem, copolymerization with optimized mol ratio of the tworesults in resinous mass. This precursor on pyrolysis to 1000deg Cresults in Si-O-C type amorphous solid black mass. XRD studieson the materials heated to 1400 deg C exhibit presence ofcrystalline Si-C and cristobalites in amorphous Si-O-C mass. Inorganic-inorganic gel system, the pyrolysed mass exhiexhibit goodresistance against oxidation at 1000 deg C.