Acta Chimica Sinica ›› 2012, Vol. 70 ›› Issue (23): 2425-2432.DOI: 10.6023/A12090679 Previous Articles     Next Articles



张文凯a, 胡成龙a, 黄赟赟a, 章明秋b, 梁晖a, 陈旭东a   

  1. a 中山大学化学与化工学院 新型聚合物材料设计合成与应用广东省普通高校重点实验室 广州 510275;
    b 中山大学化学与化工学院 聚合物复合材料及功能材料教育部重点实验室 广州 510275
  • 投稿日期:2012-09-18 发布日期:2012-11-02
  • 通讯作者: 梁晖, 陈旭东;
  • 基金资助:
    项目受国家自然科学基金重点(No. 51233008)以及国家自然科学基金(No. 20974124)资助.

Incorporation of Light-emitting Polymer into Large Cage-Type Mesoporous Silica: Toward New Luminescent Nanocomposites

Zhang Wenkaia, Hu Chenglonga, Huang Yunyuna, Zhang Mingqiub, Liang Huia, Chen Xudonga   

  1. a Institute of Polymer Science, DSAPM Lab, OFCM Institute, Sun Yat-Sen University, Guangzhou 510275;
    b Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Sun Yat-sen University, Guangzhou 510275
  • Received:2012-09-18 Published:2012-11-02
  • Supported by:
    Project supported by the State Key Program of National Natural Science Foundation of China (No. 51233008) and the National Natural Science Foundation of China (No. 20974124)

Light-emitting conjugated polymers confined in mesoporous environment create an opportunity for control of the polymer morphology for design of new functional composite materials with suitable qualities. A novel polyfluorene derivative, poly[N-octylcarbazole-co-9,9'-dioctylfluorene-co-1,3,4-oxadiazole] (PCFOz) was synthesized via Pd-catalyzed Sonogashira reaction in a mixture of 3,6-dibromo-9-octylcarbazole, 2,5-bis-(4-bromo-phenyl)-[1,3,4]-oxadiazole and 2,7-diethyne-9,9'-dioctylfluorene with Pd(PPh3)2Cl2 and CuI as the catalyst. The large cage-like mesoporous silica FDU-12 with hexagonal prism morphology was successfully synthesized and modified with TMCS (trimethylchlorosilane). The composite material was prepared by incorporating PCFOz into FDU-12 via one-step liquid-phase self-assembly method, and then fully characterized by mean of X-ray di?raction, nitrogen physisorption porosimetry, scanning electron microscopy (SEM), transmission electron microscope (TEM) and thermogravimetric analysis. The absorption spectra of composites showed a red-shift and narrower band as compared to pristine film, indicating the polymer chains packing in a special style in the cage type pores with a narrower excitonic energy distribution. PL spectra of composite materials suggested that the cages could incorporate more than one chain but less interchain species formed in cages compared with aggregates in film. The fluorescence decay kinetics observed longer exciton lifetimes in the composites resulting from the reduced exciton mobility and strong torsional distortions. Fluorescence signal from composite materials observed by laser scanning confocal microscope showed 20-times-higher than that obtained from pristine polymer film. Temperature dependence of PL spectra of composites was examined by heating the samples from 40 to 450 K, resulting in less than 10% decrease of PL intensity but no spectra variation for nanocomposites, as compared with 52% decrease of PL intensity accompanying with green-band rising for pristine PCFOz. Photostability tests were performed under the radiation of highly focused UV beams, suggesting that the excitons in the PCFOz within the pores of FDU-12 possessed better environmental stability.

Key words: light-emitting polymer, fluorescence, nanocomposites