Inorganic-organic materials composed of TiO2/SiO2/polydimethylsiloxane with several molar ratios of the precursors in the starting solution have been studied. The thickness of the layers ranges from 1.2 mu m to 400 nm, depending on the burning temperature and on the composition of the layers. The results indicate that the decrease of the concentration of TiO2 does not have a critical impact on the speed of photodegradation, for the molar ratio TiO2/PDMS equal to 0.25/0.5 or higher. When the amount Of SiO2 decreases, the chemical resistance decreases, too. (c) 2005 Elsevier B.V. All rights reserved.