Structure and optical properties of the photosensitive hybrid Ti-contained polymer materials for photonics

Titanium-containing interpenetrating polymer networks (Ti-IPNs) based on the cross-linked polyurethane, poly (hydroxyethyl methacrylate) and poly (titanium oxide) have been synthesized. First poly (titanium oxide) was synthesized by sol-gel method in the presence of 2-hydroxyethyl methacrylate at different molar ratio of Ti (OPri)(4)/H2O. The results obtained by method of optical spectrophotometry shows that the light transmission coefficients (T, %) of titanium-containing interpenetrating polymer networks samples was 90.7-91.0% at lambda = 650 nm. According to EPR data, UV irradiation in the air at room temperature of Ti-IPN samples is accompanied by appearance of signal of paramagnetic centers with broad isotropic signal at g(1) = 2.010 and also noticeably splitted signal at g(2) = 2.003 and g(3) = 1.967. First and second of them can be ascribed to the oxygen-containing "hole scavenger", while the third one is associated with the Ti3+ paramagnetic ions. The low rate of the electron hole pair recombination at room temperature in the air demonstrates efficient separation of the charged particles in the hybrid material. X-ray diffraction analysis indicates that Ti-IPN sample have an amorphous structure. UV-induced charge separation and subsequent charge recombination in Ti-IPNs cause the changes in short-range order in the arrangement of polymer macrochains.