TIO2-BASED POROUS MATERIALS OBTAINED FROM GELS, IN DIFFERENT EXPERIMENTAL CONDITIONS

The gels which are precursors of TiO2 porous materials are prepared by the controlled hydrolysis-condensation of titanium isopropoxide by po lymeric method. In the present work, a study of the influence of diffe rent experimental conditions (water/alkoxide ratio, solvent/alkoxide r atio and temperature) on the structure and texture of the polymeric ge ls obtained with the same type of alkoxide has been investigated. The structural and textural modifications for the unsupported materials ha ve been detected using DTA/TGA, XRD, specific surface area and pore si ze computerized measurements. The optical properties of the supported materials deposited on silicon wafers have been investigated using ell ipsometric method. Supported and unsupported porous materials with dif ferent structure and texture have been obtained depending on different experimental and thermal treatment conditions.