3-(Glycidoxypropyl)-trimethoxysilane-TiO2 hybrid organic-inorganic materials for optical limiting

A guest-host solid state system based on silica-titania hybrid organic-inorganic materials and fullerene derivatives has been developed for optical limiting applications. The hybrid host matrix has been prepared by sol-gel processing of 3-(glycidoxypropyl)-trimethoxysilane (GPTMS). Titanium butoxide or TiCl4 have been used in two different syntheses as the catalysts of the epoxy ring opening in GPTMS and the polyethylene oxide formation. The microstructure of the hybrid matrix has been studied by Fourier transform infrared spectroscopy. UV-VIS spectra and optical limiting measurements of the doped materials have shown that in the TiCl4 derived matrix clustering of fulleropyrrolidine (FP) molecules is avoided and optical limiting comparable to solution samples is achieved. In the titanium butoxide derived matrix, instead, the aggregation of FP degraded the optical limiting properties. The laser damage threshold in the TiCl4 synthesized matrix has been also found to be larger than in the titanium butoxide derived material.