Sol-gel processing of spirosilicates

摘要: Abstract The sol-gel transition of tetra-coordinated spirosilicate via hydrolysis and condensation under acidic basic conditions is examined to elucidate the effect catalyst, reaction time temperature on properties obtained gel. main advantage this process low employed, producing a solid network with high specific surface area. FTIR spectroscopy TGA analysis were used characterize formation siloxane bonds (Si–O–Si). It found that can be hydrolyzed both acid base catalyzed conditions. rate silicates shown at minimum in 0.001M HCl, which iso-electric point silica. prepared xerogel has low-density an amorphous material area 596 m 2 /g. Besides catalyst media, type precursor also strong influence gel formation. An aminospirosilicate, six-membered ring, containing methyl amino groups as substituents, was chosen for study. resulting determined by fact obtain Si–O–Si bonds, higher concentration solvent are more favorable, due length branching alkyl portion.