Molecular growth pathways in silica sol-gel polymerization

Technical Report · Sun Jan 01 04:00:00 EST 1989

DOI:https://doi.org/10.2172/6236739· OSTI ID:6236739

Ramamurthi, S. D.

An analytical protocol involving gas chromatography (GC), gas chromatography-mass spectrometry (GCMS), and /sup 29/Si//sup 1/H/ NMR spectroscopy, was developed to determine the structures of the polysilicate intermediates formed during silica sol-gel polymerization. This protocol allowed the structural identification of mono- through hexasilicate species (1less than or equal to /times/ less than or equal to6 in (Si/sub x/O/sub y/) (OCH/sub 3/)/sub a/) formed during partial hydrolysis and condensation of tetramethylorthosilicate. The analytical protocol employing capillary gas chromatography was applied to monitor the stoichiometry, structures, and abundances of low molecular weight polysilcates (1less than or equal to /times/ less than or equal to6 in (Si/sub x/O/sub y/)(OCH/sub 3/)/sub a/) formed during partial hydrolysis of methanolic tetramethylorthosilicate under acidic (HCl) and basic (KOH) conditions. The same procedure was applied to study the redistributions of methanolic hexamethyldisilicate and octamethyltrisilicate under similar reaction conditions. The polysilicate molecular weight distributions (expressed in terms of mole percent of total silicon present) were determined as a function of the degree of polymerization. 69 refs., 33 figs., 16 tabs.

• Research Organization: Indian Inst. of Tech., Kanpur (India)
• DOE Contract Number: AC02-76ER01198
• OSTI ID: 6236739
• Report Number(s): DOE/ER/01198-T36; ON: DE89011224
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
CERAMICS
CHALCOGENIDES
CHEMICAL ANALYSIS
CHEMICAL PREPARATION
CHEMICAL REACTIONS
CHROMATOGRAPHY
DECOMPOSITION
GAS CHROMATOGRAPHY
GLASS
HYDROLYSIS
LYSIS
MINERALS
MOLECULAR STRUCTURE
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
POLYMERIZATION
QUANTITATIVE CHEMICAL ANALYSIS
SEPARATION PROCESSES
SILICA
SILICATES
SILICON COMPOUNDS
SILICON OXIDES
SOL-GEL PROCESS
SOLVOLYSIS
SYNTHESIS