论文部分内容阅读
以4-氯亚甲基苯乙烯和硫脲为原料,获得含有烷基异硫脲盐的苯乙烯类可聚合单体（TSt）,然后将其与N-异丙基丙烯酰胺（NIPAM）共聚合合成温敏性聚合物P（NIPAM-co-TSt）,进一步在弱碱性条件下使得有机异硫脲盐与Pb（AcO）2 3H2O中的铅源反应生成含有PbS纳米粒子的PbS@P（NIPAM-co-TSt）聚合物复合材料.利用红外光谱（FTIR）、核磁（1H NMR）、X射线衍射（XRD）、荧光光谱（FL）等手段对聚合物及复合物进行了各项表征,以确认PbS@P（NIPAM-co-TSt）复合物的合成,并用纳米粒度仪和透射电镜法等对聚合物胶束及复合物颗粒的大小与形貌进行了测定.结果表明PbS@P（NIPAM-co-TSt）纳米聚合物复合物既具有良好的荧光性能,且其荧光特征可随体系的温度和浓度而发生变化、具有LCST（低临界溶解温度）特征.同时发现当聚合物体系中引入了PbS形成复合物后,复合物的粒径较之前聚合物的粒径分布明显减小.我们认为类似的环境敏感型复合物能拓展聚合物的应用领域并在很多地方具有广泛的应用前景.“,”Nowadays,the environmental sensitive polymer complexes play a more and more important role in the field of science study.Herein we demonstrate that the alkylisothiouronium-containing styrene monomer（TSt） was synthesized via 4-vinylbenzyl chloride and thiourea,which could be copolymerized with NIPAM to synthesize the temperature sensitive polymer of P（NIPAM-co-TSt） by radical polymerization.Then,the PbS complexes of PbS@P（NIPAM-co-TSt） were prepared on the basis of the interaction between alkylisothiouronium and Pb（AcO）2 3H2O in the aqueous solution of weakly alkaline.Its chemical structure was characterized by detail.For example,Fourier transformation infrared（FTIR）,nuclear magnetic resonance（1H NMR）,XRD（X-ray diffraction） and fluorescence spectrum to ensure the synthesis of PbS@P（NIPAM-co-TSt） complex.Besides,nanometer granularity apparatus,dynamic light scattering（DLS） and transmission electron microscope（TEM） were employed to survey the size and physiognomy of polymer micelles and complexes.The photoluminescence properties were also studied.It was found that PbS@P（NIPAM-co-TSt） complex exhibits characteristic fluorescence intensity,which was promoted by the PbS nanoparticles.Meanwhile,its fluorescence intensity increased along with the temperature,which very consists with the LCST（lower critical solution temperature） characteristic of PNIPAM.The results indicated that its fluorescene intensity would go up with the addition of the complex’s concentration and the raising of the temperature.The diameter of PbS@P（NIPAM-co-TSt） complex can also be reduced obviously by introducing the PbS nanoparticles to the system.What is more,its diameter had a declining trend when the temperature exceeded the LCST of it and kept stable in the end.Thus,on the one hand,these kinds of complexes possess the properties in both polymers and nanoparticles,such as PbS.On the other hand,we think that such environmental sensitive complexes must have a bright future,and also could make a lot of potential applications as optical materials in a great many areas,such as biological,medical science,cells,chemistry and so on.