含噻吩单元的硅芴共聚物的合成及其蓝色电致发光性能

将少量(摩尔分数为1%—3％)含噻吩的窄带隙单体和宽带隙硅芴单体进行共聚, 合成了聚{9,9-二己基-3,6-硅芴-co-[2,5-二(2-甲基苯撑-4-基)-噻吩]}和聚{9,9-二己基-3,6-硅芴-co-[2,5-二(2-苯撑-4-基)-噻吩]}两类硅芴共聚物, 通过紫外-可见吸收光谱、光致发光光谱, 并制作聚合物发光二极管器件测试电致发光光谱等手段, 系统表征了两类硅芴共聚物材料的性能. 实验结果表明, 噻吩的加入形成了新的蓝色发光中心, 并且实现了从硅芴链段到含噻吩发光中心的有效能量转移. 通过增加发光中心结构的空间位阻来减小其共轭程度, 可以使聚合物的PL和EL光谱发生较大蓝移. 最终得到了效率为0.46%和色坐标(CIE)为(0.19, 0.16)的蓝光LED器件.     

含苯并硒二唑聚咔唑/芴类共轭聚电解质及其前驱体的合成与性能研究

采用Suzuki偶合反应合成了一系列新型的咔唑、芴和2,1,3-苯并硒二唑的共聚物——聚[3,6-(N-(2-乙基己基))咔唑-2,1,3-苯并硒二唑-9,9-双(N,N-二甲基胺丙基)芴](PCzN-BSeD)及其相应的聚电解质衍生物——聚[3,6-(N-(2-乙基己基))咔唑-2,1,3-苯并硒二唑-9,9-(双(3′-(N,N-二甲基)-N-乙基铵)丙基)芴]二溴(PCzNBr-BSeD).在聚咔唑和芴中引入不同比例的2,1,3-苯并硒二唑(BSeD)单元,引起了由咔唑和芴链段向窄带隙苯并硒二唑(BSeD)单元有效的能量转移.通过对聚合物电致发光性能的研究,发现用聚(3,4-亚乙基二氧基噻吩)(PEDOT)或聚(3,4-亚乙基二氧基噻吩)/聚乙烯咔唑(PEDOT/PVK)作为空穴传输层时,器件的性能相差不大,表明咔唑的引入较明显的改善了聚合物的空穴注入性能.而且几乎所有的聚合物用高功函数铝作阴极的器件和用钡/铝作阴极的器件具有相近的发光性能,表明这类聚合物具有良好的电子注入性能.     

绿色单峰发光聚(9,9-二烯丙基芴)的合成及其发光机制

为了得到绿色单峰发光的聚合物材料, 我们设计并合成了9位取代的二烯丙基芴单体, 在NiCl₂的催化下, 合成了可溶的聚芴衍生物, 聚(9,9-二烯丙基芴)(PAF). 较短的烯丙基链既可以增加聚芴的溶解度, 双键的存在又有利于聚芴发生分子间聚集而得到绿光发射的有机电致发光器件(OLED). PAF在溶液和薄膜状态下的荧光峰分别位于403和456 nm的蓝光区域, 而其器件ITO/PEDOT:PSS/PAF/LiF/Al(其中, ITO为氧化铟锡, PEDOT为聚(3,4-乙撑二氧噻吩), PSS为聚苯乙烯磺酸盐)的电致发光峰却红移至绿光区域(532 nm), 得到绿色单峰发光. 紫外吸收光谱、荧光发射光谱、红外光谱以及原子力显微镜(AFM)图像的结果证明, 造成PAF电致发绿光的机制为聚合物分子间聚集.     

9,9-二-(3-(9-苯咔唑基))-2,7-芘基芴的光电性质

芴类化合物作为有机电致发光材料近年来引起了人们的广泛关注, 其具有高亮度和高工作效率等性能. 本论文采用量子化学方法研究了一种新型的芴类发光材料, 9,9-二-(3-(9-苯咔唑基))-2,7-芘基芴的光电性质. 具体研究内容包括基态和激发态几何结构、前线分子轨道、能隙、电离能、电子亲和势、重组能以及吸收光谱和发射光谱等. 理论计算结果表明, 9,9-二-(3-(9-苯咔唑基))-2,7-芘基芴发射光谱为450.6 nm, 其在电致发光器件应用上是一种具有开发前景和实用价值的蓝光发光材料.     

9,9-二辛基芴的电化学聚合

在三氟化硼乙醚(BFEE)中, 9,9-二辛基芴可以直接阳极氧化制备高质量聚(9,9-二辛基芴)膜, 其电导率为1×10^－2 S/cm. 9,9-二辛基芴在BFEE中的起始氧化电位为1.25 V vs. SCE, 低于单体在0.1 mol/L Bu₄NBF₄的乙腈溶液体系中的起始氧化电位(1.52 V vs. SCE). BFEE中获得的聚(9,9-二辛基芴)膜具有良好的电化学性质. 聚合物部分溶于氯仿、四氢呋喃、二甲基亚砜等极性溶剂. FTIR和¹H NMR表明聚合反应主要发生在2,7位. 荧光光谱表明聚合物是一种良好的蓝色荧光物质.     

胺烷基侧链取代三苯胺类红光聚合物的合成及性能研究

通过Suzuki偶合反应合成了一系列胺烷基侧链取代的基于三苯胺和芴的共轭聚合物聚[4-(N,N-二甲基胺丙氧基)苯-4,4′-二苯胺-9,9-二辛基芴-4,7-二噻吩-2-基-2,1,3-苯并噻二唑](PFTD), 并对其化学结构和光电性能进行了表征. 末端胺基的存在提高了此类聚合物作为发光层应用于聚合物电致发光器件的性能(采用高功函数的金属铝作为阴极时). 结构为ITO/PVK/PFTD-5(DBT摩尔分数为5%时的聚合物)/Al的器件最大电致发射峰位于647 nm, 最大外量子效率达到了1.24%.     

含有萘并噻二唑的红光电致发光聚合物的合成和性能研究

以2,7-二溴-9,9-双(N,N-二甲基丙胺基)芴与4,7-双(5-溴-2-噻吩)-2,1,3-萘并噻二唑为共聚单体, 通过Suzuki偶合反应合成按不同比例共聚的一系列共轭聚合物, 并对它们的电致发光性能进行了研究. 结果表明, 所有的聚合物均在高功函数金属铝作阴极的器件中具有较高的发光效率, 最大电致发光外量子效率为1.3%, 好于目前广泛应用的低功函数金属(如钡, 钙等)作阴极的发光效率.     

基于螺(芴-9,9'-氧杂葸)和芴的共聚物蓝光材料的合成与表征

通过控制缩合反应物中溴取代基的位置,得到了3种基于螺(芴-9,9'-氧杂蒽)的单体.利用Suzuki 偶联反应得到3种蓝光聚合物CSSFX,USSFX和DSSFX.聚合物USSFX和DSSFX具有较高的玻璃化转变温度和热分解温度.3种聚合物表现出较低并且相近的最高占有轨道能级(-5.80 eV至-5.93 eV)和最低未占有轨道能级(-2.80 eV至-3.01 eV).螺(芴-9,9'-氧杂蒽)单元的引入可降低聚合物DSSFX的最低未占有轨道能级到-3.01 eV,同时降低聚合物USSFX的最高占有轨道能级到-5.93 eV,聚合物USSFX较低的最高占有轨道能级使其具有较好的空穴注入性能.不同气氛下的高温退火实验表明,聚合物USSFX即使在空气中长时间高温退火以后,仍能保持稳定的蓝光发射.不同拓扑结构螺(芴-9,9'-氧杂蒽)单元的引入,可以有效调节蓝光聚合物的综合发光性能.     

芴与噻吩发光共聚物的合成及其电致发光性能

采用Suzuki偶合方法合成出了一系列新型的 9,9 二辛基芴 (DOF)和噻吩 (Th)的共聚物 .其中 ,DOF与Th的投料比 (摩尔比 )分别为 95∶5 (PTF5 )、90∶1 0 (PTF1 0 )、85∶1 5 (PTF1 5 )、70∶3 0 (PTF3 0 )、5 0∶5 0 (PTF5 0 ) .所有的聚合物均可溶于常用的有机溶剂 ,如THF,CHCl3等 ,其分子量在 60 0 0～ 5 3 0 0 0之间 .当在聚芴主链中引入噻吩后 ,其发光波长发生了红移 ,最大发光波长由PTF5时的 490nm红移到PTF5 0时的 5 41nm .随着聚芴主链中噻吩含量的增加 ,最大电致发光和光致发光效率都逐渐降低 由这些聚合物所制得的器件 ,最大电致发光效率为PTF5和PTF1 0的 0 45 %.由此表明 ,在聚芴主链中引入少量的低带隙单体噻吩可以调节聚芴的发光颜色及发光效率     

电致蓝光芴取代聚芴的合成与光谱稳定性

为了筛选高效稳定的聚合物电致蓝光材料, 设计合成了三苯胺和芴取代的二芳基芴单体, 并通过Suzuki缩聚合成了交替共聚物TPAFF-co-F和TPAFF-co-P. 将二辛基芴引入聚芴的9位可以增加其溶解度, 同时具有屏蔽主链和减少主链芴9位被氧化的作用, 三苯胺基团将有利于提高空穴在阳极界面的注入能力. 200 ℃下空气中退火24 h实验表明, 在相同条件下, 绿光指数(Igreen/Iblue)顺序为聚(9,9-二辛基芴)(1.07)>TPAFF-co-F(0.65)>TPAFF-co-P (0.47), 证明了烷基芴引入减少了主链氧化的几率. 还制作了发光二极管器件, 其结构为ITO/PEDOT:PSS(40 nm)/TPAFF-co-F或TPAFF-co-P(80 nm)/Ba(4 nm)/Al(120 nm). 在高电流密度下它们保持了良好的光谱稳定性, 在547 mA·cm-2电流密度下, TPAFF-co-F的CIE(国际发光照明委员会)坐标为(0.22, 0.24), TPAFF-co-P的CIE坐标为(0.24, 0.26), 后者的电流效率为0.712 cd·A-1.     

Modification of poly(styrene-alt-maleic anhydride) with 1,3,4-oxadiazole units for electroluminescent devices

New copolymers of poly(styrene-alt-maleic anhydride) (PSMA) modified with 2-(4-aminophenyl)-5-(biphenyl-4-yl)-1,3,4-oxadiazole and hexylamine were prepared. The copolymers, characterized by UV-vis and FT IR spectroscopy, reached 1.22 mol % of the oxadiazole units relative to anhydride groups at the maximum (PSMA-4). Electric and optical properties of the copolymers were studied. The currents obtained depend strongly on the content of oxadiazole units in the copolymers. Currents measured in PSMA-4 were more than two orders of magnitude higher than those measured in the copolymers without oxadiazole. Using polymer blends made of poly(9,9-dihexadecylfluorene-2,7-diyl) and PSMA-4, blue light-emitting devices were fabricated and their photoluminescence and electroluminescence spectra were measured.     

一种基于三苯胺类共轭聚合物荧光信号开启的汞离子检测方法

通过Suzuki反应合成出主链中含9,9-二(4-二苯胺基苯基)-3,6-芴的蓝光共轭聚合物—聚[2,7-(9,9-二辛基芴)-co-3,6-(9,9-二三苯胺基芴)] (36PFT).36PFT可特异地与I-相互作用,并淬灭36PFT的荧光.当I-的浓度为0.24 mmol/L时,36PFT的荧光淬灭程度可达95％,...     

Fluorene copolymers containing bithiophene/2,5‐ or 2,6‐pyridine units: A study of their optical,electrochemical, and electroluminescence properties

Two alternating copolymers, poly[(2,5‐di(2‐thienyl)‐pyridine‐5,5′‐diyl)‐alt‐(9,9‐dioctylfluorene‐2,7‐diyl)], PFO‐TPy25T, and poly[(2,6‐di(2‐thienyl)‐pyridine‐5,5′‐diyl)‐alt‐(9,9‐dioctylfluorene‐2,7‐diyl)], PFO‐TPy26T, were synthesized by the Pd‐catalyzed Suzuki polymerization method. The pyridine units are present as trimeric monomers in these copolymers and have different connectivities to their two neighboring thiophenes, para‐ and meta‐linkages. We investigated the variations in the optical and electrochemical properties of the copolymers that arise from these different connectivities. The two polymers exhibit 5% weight loss above 410 °C and high glass transition temperatures (T_g: 113 °C for PFO‐TPy25T, 142 °C for PFO‐TPy26T). The UV–vis absorption maximum peaks of PFO‐TPy25T and PFO‐TPy26T in the solid state were found to be 449 and 398 nm respectively, with photoluminescence maximum peaks in the solid state of 573 and 490 nm respectively. Using cyclic voltammetry, we determined their energy band gaps: 3.08 eV for PFO‐TPy25T and 3.49 eV for PFO‐TPy25T. The cyclic voltammetry study of these polymers revealed that there are some differences. The electroluminescence (EL) properties of the copolymers were measured for the device configuration of ITO/PEDOT/polymers/Ca/Al. The device fabricated with the polymer containing 2,5‐pyridine exhibits pale orange emission, whereas the device fabricated with the polymer containing 2,6‐pyridine exhibits pale blue emission. The EL device fabricated with PFO‐TPy25T has a higher brightness (2010 cd/m²) and external quantum efficiency (0.1%) than the PFO‐TPy26T device (260 cd/m², 0.008%), because it has a smaller energy barrier to the injection of charges from PEDOT and Ca into the HOMO and LUMO levels. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4611–4620, 2006     

Self-encapsulation of poly-2,7-fluorenes in a dendrimer matrix.

The synthesis and characterization of complex dendritic, rigid rod poly-2,7-fluorene homopolymers and copolymers via a macromonomer approach is reported. Several 2,7-dibromofluorene monomers containing benzyl ether dendrons (generations 1, 2, and 3) in the 9,9'-position of the fluorene ring were prepared and employed in condensation polymerizations to yield both homopolymers and copolymers with diethylhexylfluorene. Fluorescence measurements of the materials reveal extensive conjugation along the polymer backbone. The determination of the solid-state PL spectra and quantum efficiencies showed that there is an apparent optimum size of the dendritic side groups with the [G-2]-derivatives showing high reactivity with associated site isolation of the conjugated chain. AFM analysis and DSC results confirmed that the hybrid polymers and copolymers did not show any sign of a microphase-separated morphology. First EL-results demonstrated that the homopolymers have higher turn-on voltages then the corresponding copolymers.     

芴酮对聚醚侧链聚芴体系的影响: 合成, 表征及光物理性质的研究

利用Yamamoto聚合反应, 通过调节单体2,7-二溴9,9'-二-(三乙氧基甲基)芴和2,7-二溴芴酮的比例, 合成了侧链为极性聚醚链, 芴酮含量逐渐增加的聚芴系列. 通过聚合物溶液及固态薄膜的紫外荧光谱图, 深入研究芴酮作为能量受体的能量转移过程及其对聚合物光物理性质的影响. 结果表明: 稀溶液中体系呈现聚芴本征态的荧光发射, 能量转移对溶液浓度具有依赖性; 固态薄膜中能量转移效率随芴酮含量的增加而快速增长, 退火后这种现象更加明显.     

新型超支化聚(芴-co-吡啶并[3,2-b]吡嗪)共聚物的合成与发光性能

合成了新型三溴代的含有吡啶并[3,2-b]吡嗪的化合物, 通过Suzuki缩聚反应合成了以吡啶并[3,2-b]吡嗪为核, 以9,9-二辛基芴为枝的超支化共聚物. 该共聚物在甲苯和四氢呋喃等有机溶剂中具有较好的溶解性能. 采用共聚物制备了结构为ITO/PEDOT/polymer/Ca/Al的发光器件, 其中基于共聚物PFPQ-2的器件在电流密度为3.8 mA/cm²时得到蓝光发射, 最大外量子效率为1.29%, 最大亮度为1173 cd/m², 色坐标为(0.16, 0.11).     

Aliphatic-aromatic copolycarbonates derived from 2,2,4,4-tetramethyl-1,3-cyclobutanediol

The synthesis of copolycarbonates with high aliphatic contents for possible applications as optical plastics is described. Copolymers of 2,2,4,4-tetramethyl-1,3-cyclobutanediol (TMCBD) with a series of 14 bisphenol derivatives were prepared and characterized. The refractive index of these materials varies from 1.49 for the 2,2-hexafluoropropane substituted copolymer to 1.57 for the 9,9-fluorene substituted copolymer; thus, all of the copolymers exhibit lower refractive indices than the bisphenol A homopolycarbonate. The glass tran-sition temperatures of the copolymers vary from 110 to 210°C; the beta transition tem-peratures vary from -70 to 0°C when measured at 10 Hz by dynamic mechanical analysis. The copolymers exhibited good thermal stability (0–3% weight loss) when heated above the glass transition temperature, and only undergo extensive decomposition (80–90%) at 300–360°C. © 1995 John Wiley & Sons, Inc.     

Light‐emitting copolymers based on fluorene and selenophene—Comparative studies with its sulfur analogue: Poly(fluorene‐co‐thiophene)

A series of soluble conjugated copolymers derived from 9,9‐dioctylfluorene (FO) and selenophene (SeH) was synthesized by a palladium‐catalyzed Suzuki coupling reaction with various feed ratios of SeH to FO less than or equal to 50%. The efficient energy transfer from fluorene segments to narrow band‐gap selenophene sites was observed. In comparison with the very well studied copolymer poly(fluorene‐co‐thiophene), poly(9,9‐dioctylfluorene‐co‐selenophene) (PFO‐SeH) shows redshifted photoluminescence (PL) and electroluminescence (EL) emission. PL spectra of the PFO‐SeH copolymers show a significant redshift along with increasing selenophene content in the copolymers and also with increasing polymer concentration in solution. PL quantum efficiency of the selenophene‐containing PFO copolymer is much lower than that of corresponding PFO‐thiophene (Th) copolymers. All these features of PFO‐SeH copolymers can be explained by the difference in aromaticity of selenophene and thiophene heterocycles and the heavy atom effect of Se in comparison with S‐atoms. The device fabricated with PFO‐SeH15 as the emissive layer exhibited high external quantum efficiency (0.51%) at a luminance of 1570 cd/m². Device performance is limited by electron injection and the strong quenching effect of Se atoms. Devices with PFO‐SeH copolymers blended into PFO homopolymers show significant improvement in device performance. External quantum efficiency as high as 1.7% can be obtained for PFO‐SeH30/PFO blend devices. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 823–836, 2005     

Fluorene-based copolymers for color-stable blue light-emitting diodes

A series of random conjugated copolymers (PFO-HBT) derived from 9,9-dioctylfluorene (DOF) and 2-hexylbenzotriazole (HBT) is prepared by the palladium-catalyzed Suzuki coupling reaction with the feed HBT molar ratio around 1%, 5% and 15%. By copolymerizing 2-hexylbenzotriazole into the backbone of polyfluorene, an efficient colorfast blue light-emitting polymer system is developed. The device with the structure of ITO (indium tin oxide)/PEDOT/PVK/PFO-HBT1/Ba/Al exhibits the highest external quantum efficiency 1.62% with luminance efficiency of 2.69 cd/A, power efficiency of 1.25 lm/W and the CIE coordinates of (0.15, 0.17). The EL spectra are stable at the increased current density and continuous operation without significant change of CIE.