羧酸型聚芴/二氧化钛杂化材料的制备及其荧光猝灭行为

Preparation and Fluorescence Quenching Behavior of Carboxylated Polyfluorene/Titanium Dioxide Hybrid Materials

通过Suzuki偶合反应合成了聚[9,9-二辛基芴-9,9-双(丙酸基)芴](PF8COOH),并采用溶胶-凝胶法制备了羧酸型聚芴/二氧化钛(Ti O2)杂化材料。通过核磁共振氢谱(1H NMR)、凝胶渗透色谱(GPC)、紫外-可见吸收光谱(UV-Vis)、X射线衍射(XRD)和荧光发射光谱对聚合物及其杂化材料进行了表征,并研究了杂化材料的荧光猝灭行为。结果表明,所合成的PF8COOH数均分子量为19 600,PF8COOH的紫外-可见吸收和荧光发射光谱较聚(9,9-二辛基芴)(PF8)均发生红移。通过溶胶-凝胶法制得了PF8COOH/Ti O2杂化材料,其中Ti O2主要为金红石型。杂化材料出现明显的荧光猝灭现象,Ti O2含量越大则杂化材料的荧光猝灭现象越明显。羧基的引入可使聚芴与Ti O2之间的相互作用增强,电子更容易从聚芴向Ti O2转移,因而PF8COOH/Ti O2杂化材料的荧光猝灭现象比PF8/Ti O2杂化材料更明显。

Poly[(9,9-bis(3'-propanoate)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PF8COOH) was synthesized by Suzuki coupling, and carboxylated polyfluorene/titanium dioxide ( TiO2 ) hybrid materials were prepared through sol-gel method. The polymer and its hybrid materials were charac-terized by 1H NMR, gel permeation chromatography (GPC), ultraviolet-visible spectroscopy (UV-Vis) , X-ray diffraction ( XRD) , and photoluminescence spectra. The fluorescence quenching be-havior of the hybrid materials was investigated. The results indicate that the number-average molecu-lar weight of PF8 COOH is 19 600 , the UV-Vis absorption and the photoluminescence spectra of PF8COOH show a red shift relative to poly(9,9-dioctylfluorene)(PF8). PF8COOH/TiO2 hybrid materials are prepared through sol-gel method. TiO2 mainly has rutile crystal structure in the hybrid materials. Fluorescence quenching phenomenon can be obviously observed in the hybrid materials, and the greater TiO2 content is, the more obvious the fluorescence quenching phenomenon in the hy-brid materials is. Moreover, the interaction between polyfluorene and TiO2 can be enhanced as car-boxyl being introduced and electrons can transfer from polyfluorene to TiO2 more easily, thus the flu-orescence quenching phenomenon of PF8COOH/TiO2 hybrid materials is more obvious than that of PF8/TiO2 hybrid materials.