【作者】 宋亮；

【导师】 朱新远；

【作者基本信息】 上海交通大学 ， 材料学， 2010， 硕士

【摘要】 共轭聚合物由于具有良好的光电性能,目前已成为高分子科学研究领域的前沿方向。各种不同发光波长、不同结构的共轭聚合物正在被源源不断地开发出来。其中,超支化共轭聚合物合成简单,其独特的高度支化和球状结构能够抑制分子聚集体和激基缔合物的产生,因此引起了人们的关注。本论文经充分调研文献后,结合课题组在超支化聚合物和超分子化学方面的研究基础,设计并合成了一类含亚胺键的超支化共轭聚合物,也称超支化共轭聚甲亚胺,并对该类超支化共轭聚合物的光学性能和功能进行了较为系统地探索,本文主要研究内容分为以下两个部分:(1)提出了利用末端-主链间相互作用调节超支化共轭聚合物光学性能的新策略:采用3, 3-对二氨基联苯与对苯二甲醛的A2+B4缩聚反应体系成功合成了具有一定溶解性的超支化共轭聚甲亚胺。超支化聚甲亚胺具有高度支化的三维空间结构,其大量末端氨基易与主链中的亚胺键形成很强的分子间相互作用,从而对其光学性质产生了非常大的影响。改变反应单体的摩尔配比,可以调节超支化聚甲亚胺末端端基的种类和数目,因此改变了聚合物末端-主链间相互作用和相应的光学性质。此外,通过加入掺杂物,如加入质子酸将末端氨基和亚胺键质子化,加入金属离子与亚胺键上氮原子螯合,加入环糊精将末端端基包覆在其空腔内形成“绝缘层”等手段,改变了超支化聚甲亚胺末端-主链间相互作用,实现了对其光学性质的调控。(2)利用所合成的超支化共轭聚甲亚胺作为纳米反应器,成功制备了尺寸小且均一、分散性好的CdS纳米量子点。亚胺键上的氮原子含有未成键的孤对电子,能够将Cd2+很好地稳定在超支化聚甲亚胺(HPPAM)空腔内的位点上,然后通过加入S2-,原位生成CdS量子点,得到了CdS/HPPAM纳米复合物。透射电镜、动态光散射、荧光光谱、红外光谱等分析结果表明,我们的确得到了CdS/HPPAM纳米复合物。延长陈化时间,CdS/HPPAM纳米复合物荧光强度几乎没有发生变化,说明超支化聚合物的致密包覆防止了量子点的聚集,从而避免了荧光淬灭。更多还原

【Abstract】 Conjugated polymers have received considerable attention in both academic research and industrial applications because of their fantastic photoelectric properties. A variety of conjugated polymers with different light-emitting wavelengths and structures are being developed. Due to the simple preparation process together with the unique highly branched and globular structure which helps to suppress the aggregation and excimer, hyperbranched structure has been introduced into the conjugated polymers.In the present work, a new kind of hyperbranched conjugated polymers based on imine bond, which is also known as polyazomethine, has been designed and synthesized. Furthermore, two aspects including optical properties and functionalities of this kind of polymers have been studied. The dissertation is consisted of two parts as follows:(1) A kind of hyperbranched conjugated polyazomethine has been successfully prepared by the polycondensation of 3, 3’-diaminobenzidine with terephthalaldehyde. Because of the highly branched architecture, the terminal amino groups and the imine linkages in the backbone can easily form intra- or inter-molecular interactions, which affect the optical properties greatly. Based on this point, a simple approach to tune optical properties of the hyperbranched conjugated polymers has been developed via only adjusting the terminal-backbone interactions. Not only varying monomers feeding ratio to change the species and quantity of end-groups of hyperbranched polymer, but also adding some dopants, such as adopting acid to protonate the terminal amino groups and imine bonds in the main chain, adopting metal ions to coordinate the nitrogen atom of imine bonds, or adopting cyclodextrin to encapsulate the terminal groups which act as an insulating layer, can alter the terminal-backbone interactions. Correspondingly, the optical properties of hyperbranched conjugated polymers have been controlled.(2) The hyperbranched conjugated polyazomethine (HPPAM) has been used as a nanoreactor to prepare CdS quantum dots with small size and good dispersion. Since the nitrogen atom in the imine bond contains lone-pair electron, it can coordinate Cd2+ stably in the hyperbranched cavity. After adding S2-, the CdS can be synthesized in-situ. The CdS/HPPAM nanocomposites have been confirmed by Transmission Electron Microscope (TEM), Dynamic Light Scattering (DLS), Fourier Transform Infrared Spectroscopy (FTIR), Fluorescence (FL) tests. Furthermore, the effect of aging time on the fluorescence intensity of CdS/HP-PAM nanocomposites has also been studied. The results show that due to the encapsulation of hyperbranched polymer, the fluorescence intensity is almost unchanged, indicating no fluorescence quenching with the aging time increasing.更多还原