多功能两亲梳状聚合物的合成及包覆荧光量子点

利用溶液聚合和成酰胺反应合成了多功能梳状两亲性共聚物,聚(甲基丙烯酸-co-甲基丙烯酸十八酯)-(乙醇胺-乙二胺叶酸)(PSM-EE-FA).用红外光谱(FTIR),核磁共振(1H-NMR)及凝胶渗透色谱(GPC)表征了该聚合物的结构及分子量分布.实验结果证明合成了该聚合物,其数均分子量(Mn)为28600,多分散性为1.375.用该两亲梳状聚合物包覆油溶性CdSe/ZnS量子点,通过相转移作用,得到水溶性靶向量子点(PSM-EE-FA-QDs).该水溶性量子点溶液具有较好的稳定性.通过紫外-可见(UV-Vis)及荧光发射光谱分析对该量子点的光学性质进行研究.结果表明,PSM-EE-FA-QDs的紫外-可见光谱及荧光发射光谱峰形与原量子点基本一致.由于量子点表面聚合物层的形成,峰位发生少量红移.该量子点水溶液的荧光强度是原量子点氯仿溶液的98%,荧光产率是原量子点氯仿溶液的95%.动态光散射(DLS)及透射电镜(TEM)测试结果表明水溶性量子点分布均匀.合成的水溶性量子点不但光学性能稳定,而且聚合物及水溶性量子点的合成方法较为简便.

SYNTHESIS OF A MULTIFUNCTIONAL COMB-TYPE AMPHIPHILIC POLYMER AND ITS USE FOR ENCAPSULATING LUMINESCENT QUANTUM DOTS

Solution polymerization and amidation reaction were used to synthesize the multifunctional combtype amphiphilic polymer,poly(stearyl methacrylate-co-methylacrylic acid)-(ethanolamine-ethanediamine-folic acid) ( PSM-EE-FA ). A study on structure and configurations was conducted through Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (1H-NMR). The molecular weight distribution was determined by gel-permeation chromatograpy ( GPC ). It was found that the polymer was synthesized successfully,and that the number-average molar mass and the polydispersity index were 28600 and 1. 375 respectively. Through the phase transfer process,the amphiphilic polymer was used to encapsulate hydrophobic CdSe /ZnS core-shell quantum dots ( QDs) in chloroform to get water-soluble,targeting quantum dots ( PSM-EE-FA-QDs). The water-soluble QDs solution was stable. The optical properties of PSM-QDs were determined by ultraviolet-visible (UV-Vis) and fluorescence emission spectrum. As shown in the results,the UV-Vis and fluorescence emission peaks were similar to those of the original hydrophobic QDs. However,because of the formation of the polymer layer on the surface of the QDs,the red-shifts of the peaks were observed. The resulting PSM-EE-FA-QDs retained 98% of the photoluminescence value of the original CdSe /ZnS QDs in chloroform. The quantum yield (QY) of the PSM-EE-FA-QDs was 95% of the original QDs. With the dynamic light scattering (DLS) and transmission electron microscopy ( TEM) results,it was indicated that the water-soluble QDs were well-dispersed within the polymer. In addition to good performance of PSM-EE-FA-QDs,the synthesis of the copolymer and the corresponding water-soluble QDs is relatively simple.