Organosilicon gels containing silicon-silicon bonds, precursors to novel silicon oxycarbide compositions

Reaction pathways during the thermal conversion of polysiloxane precursors into oxycarbide ceramics

“…≡Si-CH 3 + ≡Si-H → ≡Si-CH 2 -Si≡ + H 2 (8) ≡Si-CH 3 + ≡Si-CH 3 → ≡Si-CH 2 -CH 2 -Si≡ + H 2 (9) Based only on these reactions, one would expect more methane from T gel which contains enough CH 3 -Si groups. However, this did not happen.…”

“…2,[7][8][9][10] There is, however, considerable disagreement over the reaction temperature range and types of reaction sequences taking place. These discrepancies in the published literature has led to the present work.…”

Electromagnetic wave absorbing properties of glucose‐derived carbon‐rich SiOC ceramics annealed at different temperatures

“…Diffraction peaks located at 2θ of 21.6° and 35.2° correspond to the amorphous SiO 2 and SiC phase, respectively, which reveal the crystallization degree of SiO 2 and SiC increase with the increase in temperature and the content of glucose. [21][22][23][24][25] Therefore, the glucose-SiOC nanocomposites can gradually crystallize with the increase in heating temperature and the content of glucose. The crystallization degree of SiC gradually increases with the increase in heat-treatment temperature and the amount of glucose owing to the phase separation as shown in Equation (1).…”

Preparation and structure of silicon oxycarbide glasses derived from polysiloxane precursors

“…Thus we reported the preparation of precursors cross-linked by Si--Si [8] or Si---CHa---CH2--Si bridges [9], leading after pyrolysis to silicon oxycarbide phases with low O/Si ratios. For example, starting from vinydichlorosilane, ViHSiC12, a cross-linked oligovinylsiloxane (COVS precursor) was obtained in two steps: hydrolysis/condensation of ViHSiC12 led to a mixture of cyclic oligovinylsiloxanes.…”