SiO2-iron oxide composites obtained by sol-gel method

Composite SiO2-iron oxide materials were prepared by three experimental pro cedures. In the first case (1), the iron oxides were precipitated during th e sol-gel process. In the second case (2), the SiO2 matrix was initially ob tained, and the iron oxides were formed by thermal treatment after impregna tion of a soluble Fe2+ salt in the previously processed matrix. In the thir d method (3), ferrite powders, prepared by wet chemical method, were embedd ed into a SiO2 based sol-gel matrix. Two type of precursors (tetraethoxysil ane (TEOS) or methyltriethoxysilane (MTEOS) were used as SiO2 sources. Vari ous properties versus both type of precursor and on the method of preparati on were noticed. Materials with high porosity and nano-sized iron oxide con tent could be prepared using the mentioned above methods.