Effect of process parameters on the electropolymerization potential and rate of formation of polypyrrole on stainless steel

Polypyrrole coatings were formed on stainless steel working electrodes in aqueous oxalic acid solution. The rate of formation of polypyrrole coatings on stainless steel increased proportionately with the current density but increased slightly with increased pyrrole concentration. Increasing oxalic acid concentration also had no significant change in the polymerization rate. The electropolymerization potential of pyrrole decreased significantly from 1.5 to 0.8 V versus SCE when the working electrode was polished. The polymerization potential, E_p, of pyrrole, increased however, with increased current density and decreased exponentially with the initial monomer and electrolyte concentration, respectively. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 2433–2440, 1997     

聚吡咯/活性炭复合电极对不同离子电吸附性研究

将小阴离子掺杂聚吡咯/活性炭(PPy/AC)复合电极与常规炭电极组装成非对称离子交换膜电容脱盐(MCDI)单元,研究了其对不同荷电量、水合半径离子的吸附性能差异。结果显示:当复合电极分别作为脱盐单元的正极或负极时,其电容吸附过程的离子尺寸依赖效应差异显著,这应该与复合电极氧化还原过程的孔径尺寸变化有关。     

Tuning the optical properties of poly(o-phenylenediamine-co-pyrrole) via template mediated copolymerization

Tailoring of conjugated monomers via copolymerization is a facile method to obtain tunable spectral, morphological and optical properties. To investigate the effect of copolymerization of pyrrole with o-phenylenediamine on the optoelectronic properties of the synthesized copolymers, the present work reports the synthesis of copolymers of o-phenylenediamine with pyrrole with varying mol ratios via chemical polymerization in methylene blue (MB) medium. Copolymerization was confirmed by Fourier transform infrared spectroscopy and ultraviolet-visible studies. Ultraviolet-visible spectroscopy revealed variation in the optical properties with the change in the monomer ratio. Fluorescence studies showed that the copolymer containing 80% poly(o-phenylenediamine) revealed highest quantum yield among all the copolymers. The emission color could therefore be tuned by careful selection of narrow band co-monomers, which could help in designing tunable fluorescence emitting materials for potential application in OLED devices.     

Mammalian-Cell-Driven Polymerisation of Pyrrole

A model cancer cell line was used to initiate polymerisation of pyrrole to form the conducting material polypyrrole. The polymerisation was shown to occur through the action of cytosolic exudates rather than that of the membrane redox sites that normally control the oxidation state of iron as ferricyanide or ferrocyanide. The data demonstrate for the first time that mammalian cells can be used to initiate synthesis of conducting polymers and suggest a possible route to detection of cell damage and/or transcellular processes through in situ and amplifiable signal generation.     

导电性塑料的研究进展

本文介绍了导电性塑料的发现、分类、品种、应用、研究重点和发展前景。对导电性高聚物的一般合成方法如链聚合法和分步聚合法、特殊的合成方法如光化学聚合进行了总结，并对共轭高聚物的导电机理作了简单的评述。     

Reduction of hexavalent chromium at a polypyrrole-coated aluminium electrode: Synergistic interactions

Adherent polypyrrole films were electropolymerized from a tosylic acid solution onto an aluminium substrate and used for the reduction of Cr(VI). The reduction of Cr(VI) to the trivalent state was found to proceed by pseudo-first-order kinetics with an activation energy barrier of 15.13 kJ mol^–1. This catalyst could be regenerated by reducing the composite at a sufficiently negative potential, in the absence of Cr(VI). However, it was found that the catalyst functioned also through a self-sustained regeneration mechanism. In this mechanism, Cr(VI) was reduced by PPy⁰ to generate PPy⁺, but the PPy⁺ was subsequently reduced to PPy⁰ by oxidation of the aluminium substrate, thus regeneration of the catalytic PPy⁰ surface giving rise to a synergistic action between the polypyrrole and the aluminium substrate.     

含钕硅钼钨杂多酸盐电催化性能的研究

报道了含钕硅钼杂多酸盐在水溶液中及其修饰到聚吡咯膜里的电化学性质,并对Ｈ２Ｏ２还原反应的催化作用进行了研究,提出了可能的机理。     

聚吡咯氧化石墨烯修饰的神经微电极阵列

利用电化学方法,在多通道神经微电极阵列芯片上制备聚吡咯氧化石墨烯薄膜材料,并对该材料的电化学行为进行了分析。对神经微电极阵列芯片采用计时电压法探究,确定了定向修饰聚吡咯氧化石墨烯薄膜的最佳电沉积条件。微电极阵列芯片为多通道实时检测神经细胞的电生理和电化学信号提供了一种新的器件,但其检测灵敏度、信噪比需进一步的提高。将聚吡咯氧化石墨烯的平面微电极阻抗值降低了92.1%,且提高了对多巴胺循环伏安响应的灵敏度,对神经电生理信号和电化学信号的检测具有重要意义。     

导电性聚吡咯/聚乳酸复合膜的制备及性能

通过乳液聚合法制备导电性聚吡咯/聚乳酸(PPy/PLA)复合膜。扫描电镜观察表明,复合膜中的聚吡咯粒子形成连续的小域分散在可生物降解的聚乳酸骨架中,红外光谱检测显示有PPy和PLA的典型吸收峰。使用自制的多通道直流电刺激系统对复合膜进行测试,结果表明,复合膜电导率衰减缓慢,导电性稳定,在560h～1146h电流持续保持在28μA～35μA之间。扫描电镜显示原代培养的成骨细胞能在导电性PPy/PLA复合膜上很好地粘附和铺展,说明复合膜具有良好的细胞相容性。     

Fabrication and characterization of silica/polypyrrole nanocomposites using silica sulfuric acid as templates

The sunflower‐like silica core‐polypyrrole (PPy) shell nanocomposites were prepared by using silica sulfuric acid as templates. The silica sulfuric acid was obtained by treating directly the silica nanoparticles with chlorosulfonic acid. The sulfonic groups (? SO₃H) on the surface of silica sulfuric acid not only offered the active sites for formation of polypyrrole particles but also acted as dopant agents in PPy. The nanostructures of sunflower‐like silica/PPy nanocomposites and hollow PPy capsules were investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The molecular structure and content of PPy were determined by Fourier transform infrared (FTIR) and thermal gravimetric analysis (TGA), respectively. The highest conductivity of nanocomposites is 2.4 S/cm. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012