Modifying the walls of mesoporous silicas prepared by supramolecular-templating

The present review is not exhaustive and rather endeavors to illustrate ways to improve the wall stability of ordered mesostructured silicas in presence of water. In situ X-ray diffraction of the phase transformations of hybrid (surfactant containing) silicas show how synthesis temperature, pH and duration control wall chemistry (thickness, condensation and hydrolysis). Ex situ studies of calcined (surfactant free, empty mesopores) silicas show how wall stability (in boiling water, under steam) is affected by synthesis conditions and/or post-synthesis treatments. (C) 2002 Elsevier Science Ltd. All rights reserved.