聚(2-甲氧基-5-辛氧基)对苯乙炔/TiO2纳米复合材料的光物理性能研究

通过原位强碱诱导下的脱氯化氢缩合聚合法制备了一系列不同纳米TiO2含量的聚(2-甲氧基-5-辛氧基)对苯乙炔/纳米二氧化钛(PMOCOPV/TiO2)光电复合材料。红外光谱和拉曼光谱证实了在纳米TiO2表面的包覆层为PMOCOPV。紫外-可见吸收光谱表明随着TiO2含量的增加PMOCOPV/TiO2纳米复合材料的吸收强度提高。高分辨透射电镜观察发现PMOCOPV/TiO2是具有核-壳结构的纳米复合粒子,直径约30 nm,其中PMOCOPV包覆层的厚度约为8~10 nm。荧光光谱研究表明,PMOCOPV/TiO2纳米复合材料的最大发射波长随着TiO2含量的增加发生红移,荧光寿命约为1 ns,且随着TiO2含量的增加荧光强度和荧光寿命得到显著提高,并通过PMOCOPV/TiO2纳米复合材料中的激子离化和电荷传输过程以及复合材料中的电势能级探讨了PMOCOPV/TiO2的荧光量子效率和荧光强度增加的机理。

Photophysical Properties of Poly (2-Methoxy-5-Octyloxy)-p-Phenylene Vinylene/TiO2 Nano-Composites

The photoelectric composites of poly(2-methoxy-5-octyloxy)-p-phenylene vinylene/nanometer TiO2(PMOCOPV/TiO2) with different nanometer TiO2 amount were synthesized through dehydrochlorination in-situ polymerization.The results of Fourier transform infrared spectroscopy and Raman spectroscopy indicated that the surface of nanometer TiO2 was coated with PMOCOPV.UV-Vis spectrum showed that the absorption of PMOCOPV/TiO2 nano-composites was strengthened in the range of violet and visible light with the contents of TiO2 increasing.The composite dimensions were observed by highly resolution transmission electron microscope,PMOCOPV/TiO2 nano-composites dispersed uniformly and possessed core-shell structure,the diameter of PMOCOPV/TiO2 was measured to be about 30 nm,and the thickness of the PMOCOPV coating was about 8-10 nm.Photoluminescence spectroscopy indicated that the maximum emission wavelength of the PMOCOPV/TiO2 was red-shifted with increasing TiO2 concentration.The fluorescence lifetime of PMOCOPV/TiO2 was about 1 ns.The intensity and lifetime of fluorescence was increased remarkably with the contents of TiO2 increasing.The mechanism of the strengthened fluorescence quantum efficiency and fluorescence intensity of PMOCOPV/TiO2 was investigated through the charge transfer,exciton dissociation and potential energy in PMOCOPV/TiO2 nanocomposites.