[Zurück]

U. Lavrencic-Stangar, M. Puchberger, N. Hüsing:
"Meso-Ordered Silica Films Formed by Sugar-Based Surfactants";
in: "Materials Research Society Symposium Proceedings Volume 726", C. Sanchez, R. Laine, S. Yang, C. Brinker (Hrg.); Materials Research Society, Warrendale, Pennsylvania, 2002, S. 111 - 116.

Sugar-based amphiphilic molecules are used as templates in the sol-gel processing of thin silica films. The films are prepared relying on solvent evaporation-induced self-assembly during dip-coating in a humidity controlled chamber. Different surfactants, such as the commercially available alkyl glycosides (e.g. n-octyl ß-D-glucopyranoside and n-dodecyl ß-D-maltopyranoside), are compared with respect to their ability to cooperatively self-assemble in alcoholic silicate solutions. The larger polar headgroup (maltose) decreases the critical packing parameter and thus beneficially influences the formation of a favorable hexagonal phase over the lamellar phase, which is formed with the glucose-based surfactant. The inorganic-organic composite films show a strong influence on the humidity during their synthesis. For non-structured films, ordering could be achieved by exposing the as-deposited films to a high humidity for several hours. The final material is characterized by X-ray diffraction, nitrogen sorption and solid state NMR techniques.