Effect of 3-glycidoxypropyltrimethoxysilane precursor on the properties of ambient pressure dried silica aerogels

• Published in: Journal of sol-gel science and technology Vol. 50; no. 3; pp. 353 - 358
• Main Authors: Shajesh, P., Smitha, S., Aravind, P. R., Warrier, K. G. K.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01-06-2009; Springer; Springer Nature B.V
• Subjects: Ceramics; Chemistry; Chemistry and Materials Science; Collapse; Colloidal gels. Colloidal sols; Colloidal state and disperse state; Composites; Drying; Exact sciences and technology; Gelation; General and physical chemistry; Glass; Inorganic Chemistry; Materials Science; Nanotechnology; Natural Materials; Optical and Electronic Materials; Original Paper; Porosity; Porous materials; Precursors; Pressure; Pressure effects; Silanes; Silica aerogels; Silicon; Silicon dioxide; Surface physical chemistry; Glycidoxypropyltrimethoxysilane; Sol–gel; Aerogel; Ambient pressure; Water; Binary compound; Inclusion; Gelation; Surface analysis; Porous material; Condensation; Precursor; Silica; Hydrolysis; Sol―gel; Adsorption; Pore; Sol gel process; Surface area; Monomer; Silane; Drying
• ISSN: 0928-0707; 1573-4846
• DOI: 10.1007/s10971-009-1926-1

The effect of an organically modified precursor, 3-glycidoxypropyltrimethoxysilane in an ambient pressure process involving aging in silane solution for silica aerogels is presented. The effect of increasing trialkoxysilane/tetraalkoxysilane precursor ratio and the influence of water to Si molar ratio on the gelation and adsorption properties were investigated. An optimum water to Si molar ratio (8) gave the fastest gelation for all precursor ratios indicating a balance between the increase in rate of hydrolysis and a decrease in concentration of the monomers. Surface area analysis proved that in the dried gel, the organic groups are largely present on the pore walls and prevent the condensation of the silanol groups during drying. This in turn prevents pore collapse and further increases the total pore volume. The inclusion of the organically functionalised silane in the process further enhances the ambient pressure drying through this effect.