NMR characterization of the chemical homogeneity in sol-gel derived siloxane-silica materials
- Univ. Pierre et Marie Curie/CNRS, Paris (France). Chimie de la Matiere Condensee
{sup 17}O NMR in solution using enriched water as reactant has been used to investigate cohydrolysis of dimethyldiethoxysilane and tetraethoxysilane, as well as methyltriethoxysilane and tetraethoxysilane. Co-condensation reactions were clearly identified in both systems: the amount of oxo bridges between the two kinds of Si units is rather large, and those bridges are stable during aging, which favor a good chemical homogeneity in the final gels. This last point was investigated on the related dried gels by {sup 29}Si Magic Angle Spinning NMR, using Cross-Polarization (CP) technique that allows to probe the local environment of the various Si sites through {sup 29}Si-{sup 1}H dipolar interactions.
- OSTI ID:
- 427688
- Report Number(s):
- CONF-960401--; ISBN 1-55899-338-X
- Country of Publication:
- United States
- Language:
- English
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