羧酸型聚芴/二氧化钛杂化材料的制备及其荧光猝灭行为

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(TiO₂)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/TiO₂杂化材料,其中TiO₂主要为金红石型。杂化材料出现明显的荧光猝灭现象,TiO₂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TiO₂之间的相互作用增强,电子更容易从聚芴向TiO₂转移,因而PF8COOH/TiO₂杂化材料的荧光猝灭现象比PF8/TiO₂杂化材料更明显。

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

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 characterized by ¹H NMR, gel permeation chromatography (GPC), ultraviolet-visible spectroscopy (UV-Vis), X-ray diffraction (XRD), and photoluminescence spectra. The fluorescence quenching behavior of the hybrid materials was investigated. The results indicate that the number-average molecular weight of PF8COOH 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 hybrid materials is. Moreover, the interaction between polyfluorene and TiO₂ can be enhanced as carboxyl being introduced and electrons can transfer from polyfluorene to TiO₂ more easily, thus the fluorescence quenching phenomenon of PF8COOH/TiO₂ hybrid materials is more obvious than that of PF8/TiO₂ hybrid materials.