Silicon-29 nuclear magnetic resonance study of hydroxyl sites on dehydrated silica gel surfaces, using silylation as a probe
A detailed /sup 29/Si NMR analysis is presented on the silylation of a series of heat-treated silica gels by hexamethyldisilizane (HMDS) with the aim of elucidating details of the surface hydroxyl population of the unsilylated samples. It is found that the complete removal of all silanol groups from silica is probably approached only at temperatures higher than those normally employed in silica treatment (i.e., higher than 1000/sup 0/C) and that some molecular water may remain on the surfaces of samples normally considered ''dried'' (e.g., evacuated at 200/sup 0/C). The population and reactivity patterns of surface hydroxyls are considered in terms of reasonable surface and dehydration models.
- Research Organization:
- Colorado State Univ., Fort Collins
- DOE Contract Number:
- AS20-81LC10652
- OSTI ID:
- 6971981
- Journal Information:
- J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 87:26; ISSN JPCHA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
400201* -- Chemical & Physicochemical Properties
ADSORBENTS
AROMATICS
BULK DENSITY
CHALCOGENIDES
CHEMICAL REACTION YIELD
CHEMICAL REACTIONS
DATA
DEHYDRATION
DENSITY
EXPERIMENTAL DATA
HIGH TEMPERATURE
HYDRIDES
HYDROCARBONS
HYDROGEN COMPOUNDS
INFORMATION
MEDIUM TEMPERATURE
MINERALS
MOLECULAR STRUCTURE
NMR SPECTRA
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC SILICON COMPOUNDS
ORGANIC SOLVENTS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
QUANTITY RATIO
SILANES
SILICA
SILICA GEL
SILICON COMPOUNDS
SILICON OXIDES
SOLVENTS
SPECTRA
STRUCTURAL CHEMICAL ANALYSIS
TEMPERATURE DEPENDENCE
TOLUENE
YIELDS