Investigation of organic-inorganic hybrid materials prepared by irradiation

New silica-based hybrid materials have been produced by gamma irradiation of the precursors using a Co-60 source. An inorganic mixture of tetraethylorthosilicate with addition of Zirconium propoxide (PrZr) (x = 0, 5 and 10 mol%) was used together with polydimethylsiloxane (PDMS) silanol terminated. Samples with volume ratios organic/inorganic of 4/1, 3/2, 1/1, 2/3 and 1/4 were prepared. The irradiation dose for gel point was observed to depend on the PDMS/INORG. volume ratio, as expected. That dose increases with decreasing volume ratio. Samples with PDMS/INORG = 2/3 were irradiated to several irradiation doses above that corresponding to the gel point, which becomes higher for higher fraction of PrZr added. The resulting samples are homogeneous, transparent and flexible being able of swelling in a good solvent of the polymer. The microstructure of the samples was investigated by Small Angle Neutron Scattering. Samples were measured as prepared, and immersed in deuterated cyclohexane. Results indicate the presence of oxide dense clusters interconnected by polymer structures. The addition of PrZr in the preparation stage increases the density of the clusters and decreases their size.