A facile method for fabrication of titanium-doped hybrid materials with high refractive index

This paper presents a facile route to prepare a series of high refractive index and homogeneous hybrid resins with titanium in the backbone by a non-hydrolytic sol-gel process. The confirmation of the condensation reaction and the formation of Si-O-Ti hetero-metal bonds in the hybrid resins were conducted by FT-IR spectroscopy, FT-Raman spectroscopy and liquid state 29 Si-NMR spectroscopy. In addition, the molecular weight and molecular size of the hybrid resin were characterized by MALDI-TOF MS and small-angle X-ray scattering (SAXS), respectively. These results show that the content of Si-O-Ti bridges, condensation degree of precursors and molecular weight and size of these hybrid resins increase depending on the TPT content from 0 to 30%. Moreover, the refractive index of the hybrid resin varied from 1.57 to 1.62 with increasing TPT content and the hybrid resin was thermally cured by hydrosilylation in the presence of a Pt catalyst to fabricate a transparent TSR hybrid film. These experimental results demonstrated that the physical and chemical properties of these hybrid films, such as visible transparency, surface roughness and surface energy, dielectric constant, thermal stability and glass transition temperature were investigated as a function of the chemical composition. This paper presents a facile route to prepare a series of high refractive index and homogeneous hybrid resins with titanium in the backbone by a non-hydrolytic sol-gel process.