| 摘要 |
Glassy articles are prepared by subjecting to hydrolysis and policondensation a solution or suspension of a suitable precursor, mainly comprising a silicon alkoxide, and by drying the obtained gel in a pressure chamber, the gel solvent having been substituted by a non-protic solvent, mainly acetone, under nitrogen flowing, at temperature and pressure conditions lower than the gel solvent critical values. The dried gel is then densified by a thermal treatment.
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