【作者】 刘丹；

【导师】 王忠刚；

【作者基本信息】 大连理工大学 ， 高分子材料， 2010， 博士

【摘要】 稀土聚合物兼具稀土离子独特的发光特性和聚合物易加工成型等优点,在发光显示、信息通讯、太阳能转换等领域具有广泛的应用前景,因此,新型稀土聚合物材料的设计及其性能研究具有重要的理论研究价值和实际意义。本文设计并合成了多种新型聚芳醚酮稀土配合物,系统地研究了材料的结构与性能之间的关系,以期获得综合性能优异并具有实际应用价值的一类新的稀土聚合物功能材料。首先采用溶液亲核缩聚反应合成了三种具有不同烷基取代基且含羧基侧基的聚芳醚酮(PEKs,包括PEK-1、PEK-2和PEK-3),其数均分子量(%)分别为66.4、46.1和45.6 kg／mol。这些聚合物均具有无定型结构,在室温下能够很好地溶解于DMSO、DMF和THF等溶剂中,其玻璃化转变温度(%)均高于210℃,热失重5%时的温度(T5)均高于402℃。分别以制得的PEK-1、PEK-2和PEK-3作为高分子配体,1,10-邻菲罗啉(Phen)为小分子协同配体,并分别以铕(Eu3+)、铽(Tb3+)、镝(Dy3+)、钐(Sm3+)为中心配位离子,制备了一系列具有可见荧光发射的新型稀土配位聚合物(PEK-RE3+-Phens,PEK=PEK-1、PEK-2、PEK-3：RE3+=Eu3+、Tb3+、Dy3+、Sm3+)。稀土离子与聚合物羧基侧基的配位反应使其均匀分布于聚合物基体材料中。PEK-RE3+-Phens表现出较好的溶解性,可溶于DMSO、DMF和NMP等溶剂,且通过旋涂或浇铸的方法可制得均一光滑的薄膜。PEK-RE3+-Phens在紫外光激发下能够分别发射出各自稀土离子的特征荧光,且高分子配体和小分子配体的协同配位使其荧光发射强度远高于相应的配位聚合物(PEK-RE3+s)和小分子配合物(RE3+-Phens)。与PEK-2和PEK-3相比,以具有最多烷基取代基的PEK-1为高分子配体的配合物的荧光强度更大。相对于小分子配合物RE3+-Phens,PEK-RE3+-Phens具有更长的荧光寿命,其中PEK-1-Eu3+-Phen和PEK-1-Tb3+-Phen的荧光寿命分别为1130和960μs。PEK-1-Eu3+-Phen和PEK-1-Tb3+-Phen的粉末、DMF溶液及薄膜样品在365 nm紫外灯激发下均能够分别发射出鲜艳的红光和绿光。利用PEK-1上的活性羧基侧基,通过酰氯化、酰胺化反应,将共轭刚性结构的Phen直接引入到了PEK-1的大分子链上,制备出了酰胺化聚芳醚酮(PPEK),其表现出较好的溶解性和比PEK-1更好的热稳定性。以制得的PPEK为高分子配体,Phen作为协同配体,制得了一类新的发射可见荧光的稀土配位聚合物(PPEK-RE3+-Phens,RE3+=Eu3+、Tb3+、Dy3+、Sm3+)。在该配位聚合物体系中,PPEK通过大分子链上引入的Phen基团的N原子与RE3+发生了配位反应。PPEK-RE3+-Phens具有较好的溶解性和成膜性。PPEK-Eu3+-Phen、PPEK-Tb3+-Phen、PPEK-Dy3+-Phen和PPEK-Sm3+-Phen在紫外光激发下可分别发射出Eu3+、Tb3+、Dy3+和Sm3+的特征荧光。为了提高稀土配位聚合物的荧光强度,在PEK-1-Eu3+-Phen和PEK-1-Tb3+-Phen体系中分别引入镧(La3+)和铈(Ce3+),制得了铕镧共配位聚合物(PEK-1-Eu0.53+Lax3+-Phens)和铽铈共配位聚合物(PEK-1-Tb0.53+Cex3+-Phens)。荧光分析结果证实,La3+和Ce3+的引入可分别显著提高相应配位聚合物的荧光强度。此外,还研究了铕铽共配位聚合物(PEK-1-Eu3+xTb3+l-X-Phens)的荧光性质,并结合CIE1931xy色度图进行了分析。结果表明,通过调节PEK-1-Eux3+Tb1-x3+-Phens体系中Eu3+和Tb3+的含量,能够获得可发射红色和绿色之间包括黄色在内的多种混合色的稀土配位聚合物荧光材料。以铒(Er3+)、钕(Nd3+)和镱(Yb3+)为中心配位离子,PEK-1为高分子配体,并选用8-羟基喹啉(HQ)为协同配体,制备了一系列具有近红外荧光发射的新型稀土配位聚合物(PEK-1-RE3+-HQs,RE3+=Er3+、Nd3+、Yb3+)。在这些配位聚合物体系中,高分子配体PEK-1和小分子配体HQ同时与RE3+发生了配位反应。PEK-1-Er3+-HQ热分解的两个阶段分别对应于HQ喹啉环的断裂和PEK-1大分子链的断裂。PEK-1-RE3+-HQs可溶于DMF、DMAc和DMSO等常用的有机溶剂,且易于成膜。荧光测试结果表明,PEK-1-Er3+-HQ、PEK-1-Nd3+-HQ和PEK-1-Yb3+-HQ在近红外区具有较强的荧光发射,最大发射波长分别位于1527、1060和978 nm处。PEK-1和HQ的协同配位作用可有效地提高这些配位聚合物的发射强度。更多还原

【Abstract】 Rare earth coordination polymers possess both unique luminescence properties of rare earth ions and excellent processability of polymer materials, which endow them potential applications in many fields such as light-emitting display, optics communications, solar-energy conversion systems, and so on. Therefore, the study on synthesis and properties of new rare earth coordination polymers is of theoretical and practical significance. In this work, using polyaryletherketones as macromolecular ligands, a series of novel rare earth complexes with excellent fluorescence properties were designed and synthesized. The relationship between the structures and properties of these materials were discussed systematically in order to obtain new rare earth functional polymeric materials with promising applications.Three carboxyl-containing polyaryletherketones with different alkyl substitutents (PEKs=PEK-1, PEK-2, PEK-3) were prepared via solution nucleophilic polycondensation reaction. The number-average molecular weights (Mn) of PEK-1, PEK-2 and PEK-3 were 66.4,46.1 and 45.6 kg/mol, respectively. PEKs all displayed the amorphous structures, and could easily dissolve in solvents such as DMSO, DMF, THF at the room tempreture. The glass transition temperatures (Tg) and 5% thermal decomposition temperatures (T5) were over 210 and 402℃, respectively.Using PEK-1, PEK-2 and PEK-3 as macromolecular ligand, respectively, and 1,10-phenanthroline (Phen) as synergistic ligand, a series of novel rare earth coordination polymers (PEK-RE3+-Phens, PEK=PEK-1, PEK-2, PEK-3, RE3+=Eu3+, Tb3+, Dy3+, Sm3+) with visible fluorescence emission were prepared. The rare earth ions could disperse homogeneously in the polymer matrix due to the formation of coordination bonds between rare earth ions and the carboxyl groups on the polymer backbone. PEK-RE3+-Phens showed good solubility and could dissolve in DMF, DMAc, NMP, and the uniform and smooth thin films could be obtained easily by spin-coating or solution-casting method. PEK-RE3+-Phens exhibited the characteristic fluorescence of the corresponding rare earth ions under UV excitation. Furthermore, PEK-RE3+-Phens showed the much higher intensities than the corresponding PEK-RE3+s and RE3+-Phens complexes, attributed to the synergistic effects of macromolecular ligand and small molecular ligand. Compared with PEK-2 and PEK-3, PEK-1 owned the most alkyl substituents, which was responsible for the higher fluorescence intensities of PEK-1-RE3+-Phens than those of PEK-2-RE3+-Phens and PEK-3-RE3+-Phens. PEK-RE3+-Phens showed the longer fluorescence lifetimes than RE3+-Phens. The fluorescence lifetimes of PEK-1-Eu3+-Phen and PEK-1-Tb3+-Phen were as long as 1130 and 960μs, respectively. The powder, DMF solution and film samples of PEK-1-Eu3+-Phen and PEK-1-Tb3+-Phen could emit bright red and green light under the UV lamp of 365 nm, respectively.By the chloroformylation and amidation reactions, Phen with conjugate and rigid structure was attached onto the PEK-1 backbone to yield 1,10-phenanthroline-functionalized polyaryletherketone (PPEK), which showed good solubility and owned the higher thermal stability than PEK-1. Subsequently, using PPEK as macromolecular ligand and Phen as synergistic ligand, a series of novel rare earth coordination polymers (PPEK-RE3+-Phens, RE3+= Eu3+, Tb3+, Sm3+, Dy3+) with visible fluorescence emission were prepared. PPEK participated in the cooridnation reaction with rare earth ions by the nitrogen atoms of Phen groups attached on PEK-1 chain. PPEK-RE3+-Phens exhibited good solubility and film-formation. PPEK-Eu3+-Phen, PPEK-Tb3+-Phen, PPEK-Dy3+-Phen and PPEK-Sm3+-Phen could emit the characteristic fluorescence of the corresponding rare earth ions under UV excitation.In order to enhance the fluorescece intensities of the rare earth coordination polymers, La3+and Ce3+were introduced into the PEK-1-Eu3+-Phen and PEK-1-Tb3+-Phen systems, respectively, and PEK-1-Eu3+0.5La3+x-Phens and PEK-1-Tb3+0.5Ce3+x-Phens were prepared. The fluorescence analysis confirmed that the introduction of La3+and Ce3+could obviously improve the emission intensities of PEK-1-Eu3+-Phen and PEK-1-Tb3+-Phen, respectively. In addition, PEK-1-Eu3+xTb3+1-x-Phens were prepared and the fluorescence properties were investigated by their fluorescence spectra, as well as the CIE1931xy chromaticity diagram. The results showed that, the rare earth coordination polymers emitting various combinations of red and green color, including yellow color, could be obtained through adjusting the contents of Eu3+and Tb3+in the PEK-1-Eu3+xTb3+1-x-Phen systems.Using Er3+, Nd3+or Yb3+as the central ions, PEK-1 as macromolecular ligand and 8-hydroxyquinoline (HQ) as synergistic ligand, a series of novel rare earth coordination polymers (PEK-1-RE3+-HQs, RE3+= Er3+, Nd3+, Yb3+) with near-infrared fluorescence emission were prepared, in which rare earth ions were coordinated simultaneously with PEK-1 and HQ. The two steps of thermal decomposition of PEK-1-Er3+-HQ were attributed to the cleavage of quinoline ring of HQ and macromolecular chains of PEK-I, respectively. PEK-1-RE3+-HQs could dissolve in the common solvents, such as DMF, DMAc and DMSO, and showed good film-forming capability. PEK-1-Er3+-HQ, PEK-1-Nd3+-HQ and PEK-1-Yb3+-HQ could emit intense fluorescence in the near-infrared region, and the strongest emission peaks located at 1527,1060 and 978 nm, respectively. The synergistic effects of PEK-1 and HQ could enhance obviously the emission intensities of these coordination polymers.更多还原