MOLECULAR DESIGN OF ALKOXIDE PRECURSORS FOR THE SYNTHESIS OF HYBRID ORGANIC INORGANIC GELS

Design, synthesis and characterization of hybrid transition metal oxide gels in which organic polymers are part of the gel network are reported and illustrated with zirconium oxide based materials. Zirconium-oxo-poly(AAEM) copolymers have been synthesized by chemical modification at the molecular level of zirconium propoxide with an organically functionalized chelating ligand (acetoacetoxyethylmethacrylate). Both polymerization reactions have been managed simultaneously, leading to hybrid organic-inorganic bushy polymers intimately interpenetrated at the nanosize scale. Zirconium oxo core is made with oxo-alkoxo AAEM modified species where zirconium is likely in sevenfold coordination. The zirconium oxo species are chemically bonded to polymeric methacrylate chains via the beta-diketo complexing function. The complexation ratio (AAEM/Zr) has been varied from 0.25 to 0.75. It appears to be the key parameter which controls the structure and the texture of these hybrid materials.