Sol-gel kinetics: /sup 29/Si NMR (nuclear magnetic resonance) and a statistical reaction model
The early time behavior of an acid catlayzed Si(OCH/sub 3/)/sub 4/ (TMOS) sol-gel was studied by high resolution /sup 29/Si nuclear magnetic resonance (NMR). Both the water producing and the alcohol producing condensation reactions were found to contribute significantly to the overall condensation rate. A general theoretical kinetic formalism which specifically treats the temporal evolution of the various chemical function groups about a specific slilcon atom was developed. The experimentally observed functional group distribution was in agreement with the distribution predicted by a simplified statistical reaction model. The mathematical framework for the study of chemical speciation at the next-to-nearest functional group level was developed. This framework was used to assign several fine structure resonances, and to show that the formation of various dimeric species is also largely statistical in nature. 17 refs., 6 figs.
- Research Organization:
- Sandia National Labs., Albuquerque, NM (USA)
- DOE Contract Number:
- AC04-76DP00789
- OSTI ID:
- 5220633
- Report Number(s):
- SAND-87-2574C; CONF-880408-11; ON: DE88008809
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360601* -- Other Materials-- Preparation & Manufacture
CATALYSIS
CERAMICS
CHALCOGENIDES
CHEMICAL PREPARATION
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHROMIUM COMPOUNDS
COLLOIDS
DECOMPOSITION
DISPERSIONS
EVEN-ODD NUCLEI
GELATION
GELS
HYDROCHLORIC ACID
HYDROGEN COMPOUNDS
HYDROLYSIS
INORGANIC ACIDS
ISOTOPES
KINETICS
LIGHT NUCLEI
LYSIS
MAGNETIC RESONANCE
NMR SPECTRA
NUCLEAR MAGNETIC RESONANCE
NUCLEI
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
REACTION KINETICS
RESONANCE
SILICON 29
SILICON COMPOUNDS
SILICON ISOTOPES
SILICON OXIDES
SOL-GEL PROCESS
SOLS
SOLVOLYSIS
SPECTRA
STABLE ISOTOPES
SYNTHESIS
TRANSITION ELEMENT COMPOUNDS