Influence of surfactant on the gelation of novel ethylene glycol esters of silicic acid

Abstract

The sol-gel transition of a novel glycol ester of ortho silicic acid is investigated by small angle neutron scattering technique. We measured the changes of scattering intensity as a function of time during gelation and show the formation of a fractal structure.

When we mix our ester with an aqueous surfactant solution no precipitate is formed as observed in common template synthesis of mesoporous materials. Because of the water solubility of our silicate precursor it can be dissolved into the surfactant phase without phase separation. During hydrolysis of the precursor ethylene glycol is produced which does not affect the hydrophobic interaction of the surfactant.

It is shown by contrast variation that surfactant does not affect the fractal dimension of the final silica gel. Measurements after gelation demonstrate the unchanged presence of surfactant micelles.