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用现场显微红外光谱电化学技术研究了聚电解质中TCNQ在电化学还原过程中二价阴离子在Li^+离子之间形成的离子对。离子对效应随阳离子浓度增加而增大。观察到一个文献中未曾报道的谱带位于2130cm^-1附近。 相似文献
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共轭聚电解质综合了传统共轭聚合物的光电性质和聚电解质的水溶性特点,使其在新一代化学生物荧光传感器中获得多种应用。本文总结了近五年来报道的共轭聚电解质(聚芴、聚噻吩、聚苯撑乙烯、聚苯撑乙炔等)用于检测生物分子的研究进展,并对共轭聚电解质的应用前景进行了展望。 相似文献
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聚电解质溶液中2.6-ANS探针的荧光谱研究 总被引:1,自引:0,他引:1
本文合成了2.6—ANS荧光探针分子,并在含有不同外加盐的NaPSS溶液中测定了探针的荧光发射光谱。结果表明:探针的荧光强度随Cs增大而增大,而探针光谱的最大发射波长和半波宽度随Cs增大而减小。当Cs达到一定值时,荧光谱参数与Cs关系曲线出现转折点,此时聚离了链以“类胶束”状态存在。 相似文献
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原位聚合制备的离子液体/聚合物电解质的研究 总被引:3,自引:2,他引:3
采用原位聚合制备出新型的BMIPF6/PMMA聚合物电解质透明弹性膜. 研究结果表明, BMIPF6/PMMA聚合物电解质体系在305 ℃时仍具有较好的热稳定性, 其安全性能优于含有机溶剂的传统非水电解质体系. 随着离子液体含量的增加, 其玻璃化转变温度逐渐减小, 离子电导率升高; 且离子电导率与温度的关系服从VTF方程. 其中, 当BMIPF6的质量分数为50%时, 该聚合物电解质的室温离子电导率高达0.15 mS/cm. 相似文献
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水溶性共轭聚电解质主要是指含离子型官能团侧链的共轭聚合物,可在水或其它极性有机溶剂中能够溶解。这类化合物把传统共轭聚合物的光电性质和聚电解质的水溶性特点结合在一起,显示出的一些独特性质,可在新一代光电器件制作和化学生物荧光传感器中获得多样的应用。本文总结了近10年来报道的水溶性共轭聚电解质的结构特点和合成方法,以及对不同化学或物理条件下光物理性质的研究,归纳了它们在新一代光电器件制作和荧光传感中的应用,并在此基础上提出了水溶性共轭聚电解质研究中尚待解决的问题,并展望了水溶性共轭聚电解质的应用前景。 相似文献
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Edward S. Yeung 《中国化学会会志》1999,46(3):351-360
Advances in sensitive optical measurement schemes have led to the detection and the physical and chemical characterization of single biological cells and individual molecules. These technological achievements are much more than the ultimate milestone in low-level monitoring. Potential applications include DNA sequencing at high speeds, probing microscale environments, monitoring environmental pollution, studying the variability of molecular conformations, detecting disease infection at an early stage, and devising molecular-scale imaging probes. 相似文献
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通过对固定在表面的TMR标记凝血酶核酸适体进行单分子荧光成像, 在单分子水平上研究了凝血酶核酸适体的折叠. 在有K+存在的条件下, 核酸适体分子与K+结合后发生折叠, 形成G四分体结构, 使得TMR靠近富含鸟嘌呤的G四分体, 并与鸟嘌呤发生电子转移, 从而导致TMR荧光强度降低. 根据TMR的单分子荧光强度观察到不同K+浓度下核酸适体在折叠和无规卷曲两种状态下的分布. 结果表明, 可利用电子转移引起的荧光强度变化在单分子水平上研究核酸适体构象变化, 这一新方法的建立是对常用的单分子荧光共振能量转移(FRET)法的重要补充. 相似文献
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We investigate the effects of a polyelectrolyte chain's configurational fluctuations on the counterion condensation theoretically. Starting with a straight‐line configuration where the polyelectrolyte chain is totally stretched, the configurational fluctuations are developed by relaxing the stretch. The amount of relaxation appears as a control parameter for configurational fluctuations in this model. The electrostatic potential generated by the fluctuating polyion is obtained through a perturbation calculation around the straight‐line configuration. Adopting the obtained electrostatic potential and using a two‐phase model calculation, the fraction of condensed counterions in the system is calculated. Effects of the Manning parameter and the fluctuations are discussed. In particular, it is shown that configurational fluctuations lead more counterions to be condensed. These observations can be understood in a transparent way in the model.
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Single molecule catalysis is very powerful in revealing catalytic mechanism at the single molecule level. But fluorescentmolecule is always necessary to take part into the catalysis directly in previous research. In order to study the single molecule electro-catalysis of non-fluorescentmolecule (SMECNFM) on nanocatalyst, we couple the SMECNFM with a single molecule fluorescence reaction. A certain number of fluorescent molecules will be generated and detected when the SMECNFM happens. Through this method, we can detect the electro-oxidation reaction of one HCOONamolecule. The stability of Pt nanocatalyst supported on active carbon is studied at the singlemolecule level by this method. This paper also provides a general way to make ultra-sensitive sensor, and to study the SMECNFM for the molecules, such as formic acid, hydrogen, oxygen, etc., on single nanoparticle. 相似文献
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由聚电解质自组装多层膜制备微孔薄膜 总被引:1,自引:0,他引:1
带有相反电荷的聚电解质通过静电作用交替沉积可以得到自组装多层膜,由于这种技术可操作性强,用途广泛,近十几年来已有了大量的研究.聚电解质多层膜在一定条件下可以形成纳米孔和微米孔.Fu等研究了聚丙烯酸和聚乙烯基吡啶组成的氢键自组装多层膜在碱溶液中溶去其中的聚丙烯酸后,剩下的聚乙烯基吡啶重构形成微孔薄膜.Mendelsohn等发现将聚丙烯酸和聚烯丙基胺自组装而成的多层膜浸入pH=2.4左右的溶液中可制备微孔薄膜.但这些方法并不能使强聚电解质多层膜形成多孔结构。 相似文献
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用聚电解质渗透汽化膜进行乙醇脱水 总被引:4,自引:1,他引:4
渗透汽化 (PV)膜过程由于可用于有机 /有机及有机 /水的恒沸或近沸混合物的分离而成为近年来膜技术研究开发的热点[1,2 ] .德国 GFT公司所制的富马酸交联 PVA脱水膜[3] 对温度为 80℃的 80 %Et OH料液 ,其分离因子为 350 ,渗透通量为 2 0 0 g/ (m2 ·h) .优秀的分离膜要求渗透通量大 ,同时具有较高的分离因子和良好的稳定性 .因此 ,提高膜的分离性能是渗透汽化技术开发应用的关键 .周继青等 [4 ]研究了 PVA/ PVP互穿网络膜的渗透汽化性能 ,发现膜的渗透通量虽有明显提高 ,但膜的选择性下降 .聚电解质具有优良的亲水性 ,可制得高水通… 相似文献
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We have prepared polyion complex (PIC) hydrogel consisting of poly(3-(methacryloylami no) propyl-trimethylamonium chloride) and poly(sodium p-styrenesulfonate) polyelectrolytes via a two-step polymerization procedure and have investigated specific ion effects on the selfhealing of the PIC hydrogel. Our study demonstrates that the mechanical properties of the PIC hydrogel are strongly dependent on the type of the ions doped in the hydrogel. The ion-specific effects can be used to modulate the self-healing efficiency of the PIC hydrogel. As the doped anions change from kosmotrops to chaotropes, the self-healing efficiency of the PIC hydrogel increases. A more chaotropic anion has a stronger ability to break the ionic bonds formed within the hydrogel, leading to a higher efficiency during the healing. 相似文献