Alkyl-glycoside surfactants in the synthesis of mesoporous silica films

Alkyl glycosides were used as templating surfactants in the sol–gel processing of thin silica films. The sols were made from a prehydrolyzed silicate solution with the addition of a glucoside or a maltoside surfactant. The sol–gel–xerogel transitions and the silica–sugar interactions were studied by IR ATR spectroscopy. The siloxane condensation rate in the silica/glycoside sol was considerably reduced compared to a pure silica system due to hydrogen bonding interactions between the silanols and the sugar head groups. Thin films were deposited on silicon wafers and characterized by IR transmission, X-ray diffraction and TEM analysis. The size of the sugar head group had a large influence on the type of the mesophases formed. The use of the glucoside surfactant only resulted in temperature unstable lamellar phases, whereas the maltosides at low concentrations assembled in curved mesophases that were stable to template removal by extraction or calcination.