A novel glycol silicate and its interaction with surfactant for the synthesis of mesoporous silicate

Abstract

A novel ethylene glycol ester of orthosilicic acid opens up new possibilities in the synthesis of mesoporous materials. As a consequence of its water solubility it can be dissolved in the aqueous phase of a pre-existing surfactant (meso-) phase without phase separation.

After hydrolysis the ethylene glycol formed affects the hydrophobic interaction of the surfactant only a little. Therefore our novel inorganic precursor in surfactant templated synthesis has the advantage to common precursors that it polymerises in the water phase of a surfactant solution without precipitation and hence large monoliths of desired shape and size can be formed. By means of small angle neutron scattering experiments we investigated the sol to gel transition of this novel precursor. The formation of a fractal structure in our systems with and without added cationic surfactant is shown from the scattering profile.

The influence of the precursor on the surfactant aggregates is also discussed. Measurements after gelation demonstrate the unchanged presence of surfactant aggregates. Furthermore, we were able to maintain a liquid crystalline surfactant phase after gelation without precipitation or phase separation.