[Zurück]


Zeitschriftenartikel:

N. Hüsing, D. Brandhuber, P. Kaiser:
"Glycol-modified organosilanes in the synthesis of inorganic-organic silsesquioxane and silica monoliths";
Journal of Sol-Gel Science and Technology, 40 (2006), 2 - 3; S. 131 - 139.



Kurzfassung englisch:
Highly porous inorganic-organic hybrid monoliths with mesopores in a macroporous network have been prepared from tris-(2-hydroxyethoxy)methylsilane (MeGMS), tris-(2-hydroxyethoxy)phenylsilane (PhGMS), 1,2-bis[tris-(2-hydroxyethoxy)silyl]ethane (bEtGMS) and 1,4-bis[tris-(2-hydroxyethoxy)silyl]benzene (bPhGMS) with or without the presence of tetrakis(2-hydroxyethoxy) silane (EGMS) and a structure-directing agent (P123). These glycol-modified organosilanes do not only offer the possibility to access monolithic gels with a high degree of substitutionwith organic groups (up to 100% of the Si-atoms) under very mild pH conditions, but also to form hierarchically organized gels exhibiting meso- as well as macropores. The amount of organosilane has been varied from 0 to 100% with respect to EGMS. The wet gels have been dried by supercritical extraction with carbon dioxide. In the present work, the sol-gel behaviour of these glycolmodified organosilanes is discussed with special emphasis on gels prepared in the presence of a block copolymeric surfactant acting as phase separation agent. The consequences on the formation of the meso- and macrostructure due to the presence of the glycol and the organic groups are presented. The structural features of the gels are investigated by various analytical techniques such as small angle X-ray scattering, nitrogen sorption, and scanning electron microscopy.

Schlagworte:
Sol-gel ; Silsesquioxane ; Mesostructure ; Templating

Erstellt aus der Publikationsdatenbank der Technischen Universitšt Wien.