聚合物辅助再沉淀法制备有机1-（2-吡啶偶氮）-2-苯酚材料

发布时间：2018-05-13 14:24

本文选题：再沉淀法 + 嵌段共聚物　；参考：《湘潭大学》2010年硕士论文

【摘要】： 近年来,纳/微米材料的合成及其性质研究引起了研究者们的广泛兴趣。与无机和高分子纳/微米材料不同,有机小分子的结构多样性、功能性以及易裁剪性,使得有机功能小分子纳/微米材料的研究越来越受到重视。在文献报道的有机纳/微米材料的合成方法中,再沉淀法因其简易的特点得到了广泛的应用。本论文采用嵌段共聚物PDMA-b-PNIPAM辅助再沉淀法制备了有机1-(2-吡啶偶氮)-2-萘酚(PAN)纳/微米材料,系统研究了共聚物浓度、PAN浓度等因素对材料形貌以及尺寸的影响,并对其生长过程进行了探讨。 (1)嵌段共聚物的合成。以S-乙基-S’-(2-甲基-2-丙酸丙炔酯基)三硫代碳酸酯(PEMP)为链转移剂,偶氮二异丁腈(AIBN)为引发剂,采用可逆加成断裂链转移(RAFT)聚合反应合成了一系列不同分子量的聚N,N-二甲基丙烯酰胺均聚物(PDMA)及聚N,N-二甲基丙烯酰胺聚N-异丙基丙烯酰胺嵌段共聚物(PDMA-b-PNIPAM)。采用GPC对所合成聚合物的分子量及分子量分布进行了分析,GPC分析结果显示链转移剂PEMP对RAFT聚合过程的可控性较好。同时采用动态光散射(DLS)对嵌段共聚物的胶束化行为进行了研究,DLS测试结果表明随着聚合物溶液浓度的增加,其临界胶束温度(CMT)降低且胶束粒径减小。 (2)有机PAN纳/微米材料的制备。利用温敏型嵌段共聚物PDMA-b- PNIPAM辅助再沉淀法制备了有机PAN纳/微米材料,系统研究共聚物浓度、PAN浓度等因素对纳/微米材料形貌以及尺寸的影响。采用扫描电子显微镜(SEM)对产物的形貌进行了表征,结果表明通过调控聚合物浓度或者PAN浓度,可以得到不同形貌(纤维状、棒状、束状)的纳/微米材料;红外光谱(FTIR)结果证明所得到的纳/微米材料为纯PAN而没有夹杂聚合物分子。利用紫外-可见光光谱(UV-Vis)及荧光光谱对PAN纳/微米材料的光物理性能及其生长过程进行了跟踪研究。UV-Vis测试结果表明,相对于PAN溶液的吸收峰,PAN纳/微米材料的吸收峰发生了红移现象,为J-聚集体;并且随着时间的延长,其吸收峰的强度逐渐减弱,长波拖尾现象加剧。荧光光谱则表明,PAN纳/微米材料的发射强度要比其原料稀溶液的发射强度有明显的增强,即聚集诱导的荧光增强现象(AIEE),并且在长波方向出现了新的发射峰;同时还发现,其荧光发射强度随着时间的延长而逐渐增强。
[Abstract]:In recent years, the synthesis and properties of nano / micron materials have attracted wide interest. Different from inorganic and macromolecular nano / micron materials, the structural diversity, functionality and tailoring of organic small molecules make the research of organic functional nano / micron materials receive more and more attention. The reprecipitation method has been widely used in the synthesis of organic nano / micron materials reported in the literature because of its simple characteristics. In this paper, the nanocomposite / micron material of organic 1-t2-pyridylazo -2-naphthol (pan) was prepared by block copolymer PDMA-b-PNIPAM assisted reprecipitation method. The effects of the concentration of copolymers, such as concentration of pan, on the morphology and size of the materials were systematically studied. The growth process was also discussed. Synthesis of block copolymers. The chain transfer agent (PEMP) and azodiisobutyronitrile (AIBN) were studied. A series of polyN- (N-dimethylacrylamide) homopolymers (PDMAs) with different molecular weights and poly (N-dimethylacrylamide) -N-isopropylacrylamide block copolymers (PDMA-b-PNIPAM-) were synthesized by reversible addition chain transfer polymerization (RAFT). The molecular weight and molecular weight distribution of the synthesized polymers were analyzed by GPC. The results showed that the chain transfer agent PEMP had good controllability for the polymerization process of RAFT. At the same time, the micellization behavior of block copolymers was studied by dynamic light scattering (DLSs). The results of DLS showed that the critical micelle temperature (CMT) and micelle size decreased with the increase of polymer solution concentration. Preparation of organic PAN nanomaterials. Organic PAN nanowires were prepared by a thermo-sensitive block copolymer PDMA-b- PNIPAM assisted reprecipitation method. The effects of copolymer concentration and pan concentration on the morphology and size of nanocrystalline / micron materials were systematically studied. Scanning electron microscopy (SEM) was used to characterize the morphology of the product. The results showed that different morphology (fibrous, rod and bundle) nanomaterials could be obtained by controlling the concentration of polymer or PAN. The results of FTIR show that the nanocrystalline / micron materials are pure PAN without inclusion of polymer molecules. The photophysical properties and growth process of PAN nanocrystalline materials were studied by UV-Visand fluorescence spectra. Compared with the absorption peak of PAN solution, the absorption peak of pan / micron material shows a red shift phenomenon, which is a J-aggregate, and the intensity of the absorption peak decreases gradually and the long-wave trailing phenomenon intensifies with the prolongation of time. The fluorescence spectra show that the emission intensity of pan / micron material is much stronger than that of its raw material dilute solution, that is, the agglomeration induced fluorescence enhancement phenomenon is AIEEN, and a new emission peak appears in the direction of long wave, at the same time, it is also found that the emission intensity of pan nanocrystalline / micron material is higher than that of its raw material dilute solution. The fluorescence emission intensity increases with time.
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2010
【分类号】：O631.3

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