高分子化8-羟基喹啉锂的合成与静电自组装研究

设计合成了甲基丙烯酸二甲氨基乙酯(DM)含量为9.69%的丙烯酸甲酯共聚物(CPA),将制得的5-氯甲基-8-羟基喹啉(CHQ)挂接到CPA上,得到季铵型高分子化8-羟基喹啉(CPA-HQ)后,与金属离子Li+配位得到CPA-HQ-Li.化合物结构通过红外、紫外和荧光光谱等表征.多层超薄膜用CPA-HQ-Li和聚阴离子电解质(全氟磺酸)通过静电自组装制得.自组装膜的紫外和荧光相对于溶液(溶剂为四氢呋喃)发生了红移,膜的紫外吸收强度随组装膜层数增加线性增大,荧光强度随膜层数增加线性递减.高分子化8-羟基喹啉锂溶液和自组装膜的紫外和荧光光谱与文献报道一致.实验结果表明这种材料可用于有机电致发光器件(OLEDs)的制备.

PREPARATION OF AN 8-HYDROXYQUINOLINE LITHIUM-CONTAINING COPOLYMER AND ITS ELECTROSTATIC LAYER-BY-LAYER SELF-ASSEMBLY

The design of next-generation organic light-emitting diodes(OLEDs)is focused on polymers containing electroluminescent functionality with efficient charge-transport capability.It is desirable to investigate display materials which have excellent fluorescent properties of 8-hydroxyquinoline metal chelates and outstanding processing properties of polymers.An 8-hydroxyquinoline lithium(LiQ)-containing polymer(CPA-HQ-Li)was synthesized by chelating reaction of Li+ and HQ-pendant copolymer(CPA-HQ),in which CPA-HQ was prepared with 5-chloromethyl-8-hydroxyquinoline(CHQ)and a copolymer(CPA)which was synthesized with n-butyl acrylate(BA),2-(dimethylamino)ethyl methacrylate(DM),methyl methacrylate(MMA),2-hydroxyethyl acrylate(HEA)and styrene(ST).As a functional group,DM was added according to 9.69 wt% as original material in the process of synthesizing CPA.Moreover,this positive-charged polymer was suitable for thin film deposition from dilute polymer solutions,the quarternary amonium PDM was used as the cation first adsoption layer to abtain a flexible substrate,the sulfonated fluoropolymer(Nafion 117)was used as the anion hole electon transport,and then,multilayer thin films were obtained by electrostatic self-assembly(ESA).For the characterization of the structures and properties of these polymers and multilayer films,the technologies inclucding 1H-NMR,UV-Vis,FT-IR,photoluminescence(PL)spectra and gel permeation chromatography analysis(GPC)etc.were used.FT-IR analysis displays that the stretching vibration peak located initially at 1638 cm-1 is blue shifted to 1593 cm-1 nearby.It is found from UV-Vis absorbance that the absorption peak corresponding to π→π electron transition of quinoline is still present,but it is red shifted from 248 nm to 258 nm,and the n→π electron transition at 320 nm weakens or disappears.In addition,there is a broad absorption at 371 nm corresponding to the chelating of the polymer containing 8-hydroxyquinoline ligands with metal ion Li+.It is an enantiomorphous symmetrical connection between excitation and emission spectra of CPA-HQ-Li at λ_ exit=366 nm and λ_ emit=482 nm.Both the UV-Vis absorptions and fluorescence spectra of the films show a red shift compared to those examinated in tetrahydrofuran solutions.The UV-Vis absorptions show that the maximum UV absorbances of the composite films increase linearly with the number of film layers,but the fluorescence spectra reveal that the fluorescence intensity decrease linearly with the number of film layers.The results of the present work implies that these kinds of materials could be used for practical applications in OLEDs.