Analysis of surface modified colloidal silicas

Conference · Sun Jan 01 04:00:00 EST 1989

OSTI ID:5852598

Badley, R. D.; Ford, W. T.; McEnroe, F. J.; Assink, R. A.

Colloidal silica was prepared by hydrolysis of tetraethyl orthosilicate in water, ammonia, and ethanol, and its surface was modified with mercaptopropyl, aminopropyl, and octadecyl groups. The parent and modified silicas were analyzed by /sup 13/C and /sup 29/Si NMR, elemental analysis, and thermogravimetric analysis (TGA). CP-MAS /sup 13/C NMR failed to detect most of the mobile carbons, but direct polarization MAS NMR gave quantitative carbon analyses which agreed with elemental analyses. Direct polarization MAS /sup 29/Si NMR showed that esterification of colloidal silica with octadecanol at 190/degree/C did not cause additional crosslinking in the silica. But reaction with octadecyltrimethoxysilane did give a slight increase in siloxane linkages due to the surface reaction. TGA results show that the octadecylsiloxane linkage is thermally more stable than the octadecyloxysiloxane linkage. 5 refs., 3 figs., 3 tabs.

• Research Organization: Sandia National Labs., Albuquerque, NM (USA)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 5852598
• Report Number(s): SAND-89-0287C; CONF-8906187-1; ON: DE89015849
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
440300 -- Miscellaneous Instruments-- (-1989)
47 OTHER INSTRUMENTATION
ALCOHOLS
CHALCOGENIDES
CHEMICAL ANALYSIS
CHEMICAL REACTIONS
COLLOIDS
DECANOLS
DECOMPOSITION
DISPERSIONS
HYDROLYSIS
HYDROXY COMPOUNDS
LYSIS
NMR SPECTRA
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
POLARIZATION
QUANTITATIVE CHEMICAL ANALYSIS
SILICON COMPOUNDS
SILICON OXIDES
SOLVOLYSIS
SPECTRA
SURFACE PROPERTIES
SYNTHESIS