In situ preparation and fluorescence quenching properties of polythiophene/ZnO nanocrystals hybrids through atom-transfer radical polymerization and hydrolysis
In situ preparation and fluorescence quenching properties of polythiophene/ZnO nanocrystals hybrids through atom-transfer radical polymerization and hydrolysis
复制标题
原子转移自由基聚合和水解原位制备聚噻吩/ZnO纳米晶杂化物及其荧光猝灭性能
DOI：
10.1016/j.apsusc.2009.11.056
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发表时间：
2010-02-15
影响因子：
6.7
通讯作者：
Zhou, Weihua
中科院分区：
文献类型：
--
作者：
Peng, Xiaoming;Zhang, Lin;Zhou, Weihua
提出了一种原位制备共轭聚合物(CPS)与半导体纳米晶复合材料的新方法。以大分子引发剂poly(2，5-(3-(bromoisopropyl-carbonyl-oxymethylene)(噻吩基)(PTH-BR)为引发剂，采用原子转移自由基聚合法，合成了含侧基引发剂的聚甲基丙烯酸锌接枝共聚物。随后，通过在碱性水溶液中原位水解聚甲基丙烯酸甲酯/氧化锌(PTH-g-PZMA)铸膜层，成功制备了聚噻吩接枝聚甲基丙烯酸酯/氧化锌(PTH-g-PMA/ZnO)杂化异质结纳米复合材料。用质子核磁共振(H-1NMR)、傅里叶变换红外光谱(FTIR)和X射线光电子能谱(XPS)对PTH-BR、PTH-g-PZMA和PTH-g-PMA/ZnO的结构进行了表征。用扫描电子显微镜(SEM)观察了不同水解时间制备的PTH-g-PMA/ZnO薄膜的横截面形貌。扫描电子显微镜照片显示，纳米氧化锌均匀分散在聚合物中，没有任何团聚现象，且随着处理时间的延长，氧化锌纳米晶的形貌由纳米颗粒变为纳米棒。通过紫外-可见(UV-Vis)吸收光谱和荧光光谱研究了纳米复合材料的光学性质。UV-Vis吸收光谱表明，PTH-g-PMA/ZnO杂化材料的吸收带比PTH-BR杂化材料宽，说明纳米晶的存在增加了杂化材料的光学吸收区域。光致发光(PL)谱表明，PTH-g-PMA/ZnO共混物发生了荧光猝灭，在NaOH水溶液中处理2 h得到的PTH-g-PMA/ZnO的荧光强度最大猝灭了85%，这表明聚噻吩链与ZnO之间存在光致电荷转移。这些结果表明，杂化异质结纳米复合材料有望成为光伏应用的候选材料。(C)2009爱思唯尔B.V.保留所有权利。
In this paper, a new approach for in situ preparing nanocomposites of conjugated polymers (CPs) and semiconductor nanocrystals was developed. Polythiophene grafted poly(zinc methacrylate) (PTh-g-PZMA) copolymer was synthesized by atom-transfer radical polymerization (ATRP) of zinc methacrylate (ZMA) initiated from the macroinitiator poly(2,5-(3-(bromoisopropyl-carbonyl-oxymethylene) thiophene)) (PTh-Br) with pendant initiator groups. Subsequently, the polythiophene grafted poly(methacrylate)/ZnO (PTh-g-PMA/ZnO) hybrid heterojunction nanocomposites were successfully prepared by in situ hydrolysis of PTh-g-PZMA casting films in alkaline aqueous solution. The structures of PTh-Br, PTh-g-PZMA and PTh-g-PMA/ZnO were confirmed by the proton nuclear magnetic resonance (H-1 NMR) spectra, Fourier transform infrared (FTIR) spectra and X-ray photoelectron spectroscopy (XPS). The morphologies of PTh-g-PMA/ZnO films prepared for different hydrolysis time were observed in the cross-sections by scanning electron microscope (SEM). The SEM images revealed that ZnO nanocrystals were uniformly dispersed in polymers without any aggregation and the appearances of ZnO nanocrystals changed from nanoparticles to nanorods with the hydrolysis treatment time increasing. The optical properties of these nanocomposites were studied by ultraviolet-visible (UV-vis) absorption and fluorescence spectroscopy. UV-vis absorption spectroscopy showed that the adsorption band of PTh-g-PMA/ZnO hybrids was broader than that of PTh-Br, implying that the existence of ZnO nanocrystals increased the optical absorption region of hybrids. The photoluminescence (PL) spectra of the hybrids showed that fluorescence quenching occurred in PTh-g-PMA/ZnO blends and a maximum of 85% of the fluorescence intensity quenched in the PTh-g-PMA/ZnO obtained from treatment in NaOH aqueous solution for 2 h, which revealed the existence of photo-induced charge transfer between the polythiophene chains and ZnO. These results indicated that the hybrid heterojunction nanocomposites could be promising candidates for photovoltaic applications. (C) 2009 Elsevier B. V. All rights reserved.