Size and shape dependence of organo-interconnected silsesquioxanes through hydrolysis-condensation reaction conditions: Nanotubes, spheres and films

Abstract

A tris-silylated urea-based compound, 1,3,5- tris(triethoxysilylpropylureido)benzene has been synthesized. Hybrids materials with different shapes (films, spheres and tubes) are obtained upon base-catalyzed hydrolytic condensation of this compound. A self-templating process is demonstrated using electron microscopy (SEM and TEM) and X-ray diffraction (SAXS and WAXS) techniques. We show the formation of nanometer size hollow tubes according to the size of the self-templating crystalline pre-cursor. The possibility for this self-templating to occur is due to a favored dissolution of the self-assembled molecules of the precursor in a preferential direction parallel to the cross-section of the crystals. © 2007 WILEY-VCH Verlag GmbH & Co. KGaA.