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91.
A novel oligothiophene derivative containing the triphenylamine moiety with high glass transition temperature (Tg; 135 °C), 5,5′‐{bis[4‐di(4‐thiophenyl)amino]phenyl}‐2,2′‐bithiophene (TTPA‐dimer) was synthesized by the dimerization of tris[4‐(2‐thienyl)phenyl]amine (TTPA) with a palladium catalysis. Some types of electroluminescent (EL) devices that use the amorphous material for a hole‐ and an electron‐transporting with an emitting layer were fabricated. These devices emitted a bright green‐yellowish light (λemi; around 510 nm) with a small full width at half maximum (FWHM) rather than that of Alq3. The single layer EL device showed a maximum luminance of 221 cd/m2 at 8 V (0.06 lm/W at 100 cd/m2). On the other hand, the double layer (TTPA‐dimer/Alq3) EL device that used Alq3 as the electron transport material was increased up to 10830 cd/m2 at 12 V (0.89 lm/W at 300 cd/m2) and with a lower turn‐on voltage (3.2 V at 0.1 cd/m2) than other types of EL devices. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
92.
93.
By means of a vacuum time-lag method, gas transport properties of apolyimide based on 2, 2- bis (3, 4- decarboxyphenyl ) hexafluoropropane dianhydride (6FDA )and meta- phenylenediamine (mPDA ) have been measured as a function of upstream pres-sure and temperature. The results show that no gas-induced plasticization occurs for thispolyimide in the upstream pressure range from 1 atm to 20atm. The temperature depen-dence of P and D can be described by the Arrhenius equations. The activation energiesof permeation and diffusion were obtained for the gas/polymer pair studied and correlatedwith the size of penetrant gas. 相似文献
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95.
油溶性偶氮染料的合成及其性能研究 总被引:16,自引:0,他引:16
随着染料在现代科技中的广泛应用,染料的油溶性也日益受到人们的重视.如:非线性光学材料、激光盘光学信息存贮材料中使用的染料、彩色成像中的油溶性影像染料等,对染料在有机溶剂中的溶解度都有很高的要求.偶氮染料是有机染料中的主要类型,但目前对其分子结构与油溶性关系的研究甚少.本文合成了一类黄色偶氮染料(见表1),并对其色光、油溶性等性能进行了测试,发现取代基相对于偶氮基的位置,是影响偶氮染料油溶性的主要因素. 相似文献
96.
97.
以LiOH·H2O,Al2O3和Co3O4为原料,微波加热合成Li离子电池正极材料LiAlxCo(1-x)O2.通过XRD测试表征了不同Al加入量时合成产物的晶体结构,确定当x≤0.4时,产物为单一相层状结构.计算了不同x时LiAlxCo(1-x)O2的晶胞参数,随着x的增大,a值减小,c值增大.对合成LiAlxCo(1-x)O2样品进行DSC—TGA测试,结果表明,当x不同时,合成样品的热稳定性不同.SEM测试表明,合成晶体粒度较均匀,粒径在5μm左右.电化学测试表明,LiAl0.2Co0.8O2的电化学性能最好,首次循环放电容量为127mAh/g,多次循环容量损失率小于LiCoO2. 相似文献
98.
A new family of eight poly(urethane-amide-imide) (PUAI) block copolymers with the same hard block and different soft blocks were synthesized in two steps from a dianhydride monomer containing amide functions (4,4′-methylene-bis(trimellitic anhydride-N-phenylamide)) and α,ω-dihydroxy telechelic oligomers which varied in both chemical structure (polyethers: PEG, PTMG, PPG; polyester: PCL) and molar weight (MW ≅ 600 or 1000 g/mol). The PUAI were obtained in high yields (ranging from 81 to 98 wt%) and with reduced viscosities which varied from 0.36 to 0.84 dL/g (for C = 1 mg/mL in DMF at 25 °C). Their characterization by FTIR and 1H NMR fully confirmed their chemical structure. Their solubility was typically limited to a few wt/vol% even in strong apolar diprotic solvents like DMF and NMP. This particular feature showed the very strong physical cross-linking of their very stiff hard block and enabled to cast membranes capable of withstanding exposure to many common organic solvents. Systematic permeability experiments showed that the PUAI membranes could be used to separate the azeotropic mixture EtOH (20 wt%)/ETBE very easily, with interesting prospects for the purification of ETBE (a fuel octane enhancer used instead of lead derivatives in the European Community). An analysis in terms of structure-property relationships pointed out that the soft block molar weight and polarity were two key parameters for the optimization of selective permeability. The best compromise was obtained with the soft block PEG1000. The corresponding polymer led to performances so far outstanding for polyamideimides with a very high flux of more than 1.1 kg/h m2 for a normalized thickness of 5 μm at 50 °C and a selectivity α = 22.7 in the high range for this kind of separation. 相似文献
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100.
Immobilized copper(Ⅱ) in organic-inorganic hybrid materials catalyzed Ar-N coupling of arylboronic acids with imidazoles has been developed. Arylboronic acids reacted with imidazoles smoothly in the presence of a 3-(2-aminoethylamino)propyl functionalized silica gel immobilized copper(Ⅱ) catalyst (10 mol%) in methanol without any additives and bases. The reactions generated the corresponding cross-coupling products in good yields. Furthermore, silica-supported copper can be recovered and recycled by a simple filtration procedure and used for five consecutive trials without decreases in activity. 相似文献