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Cross-Condensation Reactions in an Organically Modified Silica Sol-Gel

Published online by Cambridge University Press:  21 February 2011

S. Prabakar
Affiliation:
UNM/NSF Center for Micro-Engineered Ceramics, University of New Mexico, Albuquerque, NM 87106
R. A. Assink
Affiliation:
Sandia National Laboratories, Albuquerque, NM 87185.
N. K. Raman
Affiliation:
UNM/NSF Center for Micro-Engineered Ceramics, University of New Mexico, Albuquerque, NM 87106
C. J. Brinker
Affiliation:
UNM/NSF Center for Micro-Engineered Ceramics, University of New Mexico, Albuquerque, NM 87106 Sandia National Laboratories, Albuquerque, NM 87185.
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Abstract

High resolution 29Si NMR has been used to study the extent of cross condensation taking place in a hybrid organic/inorganic sol-gel system. Tetraethoxysilane (TEOS) and methyltriethoxysilane (MTEOS) sol-gels were chosen for this purpose. The sols were prepared by acid catalyzed hydrolysis of TEOS and MTEOS with a H2O/Si ratio of 0.3. 29Si NMR shows signals due to both self-condensation and cross-condensation between TEOS and MTEOS. Resonance assignments were made by comparing the positions and intensities of peaks in the spectra of single and multicomponent systems. It was found that, within experimental error, the self- and cross-condensation rates are equal and that extensive molecular level mixing takes place during the early stages of the reaction.

Type
Research Article
Copyright
Copyright © Materials Research Society 1998

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References

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