[Photo-induced electron transfer effects of poly(2-methoxy-5-octyloxy)-p-phenylene vinylene/Y2O3:Eu3+ nano-composites].

The photoelectric nano-composites of poly(2-methoxy-5-octyloxy)-p-phenylene vinylene/Y2O3:Eu3+ (PMOCOPV/Y2O3:Eu3+) were prepared by dehydrochlorination in-situ polymerization. The result of Fourier transform infrared spectroscopy indicates that PMOCOPV is coated on the surface of Y2O3:Eu3+. Compared with PMOCOPV, the absorption of PMOCOPV/Y2O3:Eu3+ is strengthened, and a red shift of the absorption peak can be clearly observed in the UV-Vis spectrum. Photoluminescence spectroscopy indicates that the maximum emission wavelength of the PMOCOPV/Y2O3:Eu3+ is red-shifted and the intensity of photoluminescence increases in comparison with PMOCOPV. PMOCOPV/Y2O3:Eu3+ shows fluorescence increasing, which involved the inter-molecular photo-induced charge transfer process. The optical band gap of PMOCOPV/Y2O3:Eu3+ decreases. The third-order optical nonlinear susceptibility of PMOCOPV/Y2O3:Eu3+ nano-composites was measured by degenerate four wave mixing. The results show that the third-order nonlinear optical responses of PMOCOPV/Y2O3:Eu3+ nano-composites are enhanced in comparison with PMOCOPV, which can be attributed to inter-molecular photo-induced electron transfer and delocalized pi electron coupling between PMOCOPV and Y2O3:Eu3+.

[Synthesis of PANI/TiO3 nanorods composites by reverse micelle template and their properties].

PANI/TiO2 nano-composites with different amount of nanometer TiOz were synthesized by using reverse micelle formed from cationic surfactant cetyltrimethyl ammonium bromide (CTAB) as the template. The structure and properties of PANI/TiO2 nano-composites were investigated by FTIR, UV-Vis, TG, TEM and photoluminescence spectroscopy. The self-assembly mechanism of PANI/TiO2 nanorods composites in reversed micelle was discussed briefly. The results indicate that the synthesized nano-composites are PANI/TiO2 nanorods with an average diameter and length around 30-40 nm and 400 nm respectively. The infrared spectrum shows that a strong interaction exists between PANI and TiO2 nano-particles. The thermal stability of PANI/TiO2 nanorods improves with the contents of TiO2 increasing. The absorption of PANI/TiO2 nano-composites was found to be very intense in the range of violet and visible light by UV-Vis spectrum. The fluorescence of PANI/TiO2 nanorods was excited at 416 nm, and the intensity of fluorescence was strengthened greatly with increasing TiO2 concentration. The mechanism of the strengthened fluorescence quantum efficiency and fluorescence intensity of PANI/TiO2 was investigated through the charge transfer and exciton dissociation in PANI/TiO2 nanorods composites.