Effects of applied potentials on permselectivity of ions through polypyrrole/porous-polypropylene composite membrane

A composite membrane was prepared by the combination of polypyrrole with a porous-polypropylene film, and its permselectivity was investigated. The permeability and selectivity of various sodium salts through the membrane were changed with an applied potential. The permeation of anions at the positive potentials was due to the migration through the positive sites of the polypyrrole layer, as well as the diffusion from the difference of concentration and potential. The contribution of the migration effect to the anion permeation was very large. The main factors dominating the permeation character of different anion species were the size and valence of the anions. The composite membrane worked effectively as a functional separation membrane to control the ionic permeability by potential application. © 1998 John Wiley & Sons, Inc. J. Appl. Polym. Sci. 70: 647–653, 1998     

Thin polypyrrole films prepared by chemical oxidative polymerization

Polypyrrole (PPY) films with a thickness of 3–4 μm were obtained by chemical oxidation of pyrrole (PY) at the interface of chloroform and water with an oxidant (NH₄)₂S₂O₈. The films were compact and could be removed with a solid plate. The quality and compositions of these films varied with the molar ratios of the monomer and oxidant of the reaction systems. Overoxidation of polypyrrole was observed and confirmed by the characterizations via infrared spectra and elemental analysis of the films. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 2169–2172, 1998     

Optimization of electrically conductive films: Poly(3-methylthiophene) or polypyrrole in Kapton

A method to generate conductive films composed of small amounts of conductive polymer absorbed into the surface of polyimide films has been optimized. Both pyrrole (PY) and 3-methylthiophene (3MT) were evaluated as precursors for the conductive phase. Predictive models were empirically derived for each precursor to describe the effects of polymerization variables on the conductivity of the films. The variables studied were found to be highly synergistic. An optimum set of conditions was found for each conductive polymer that produces the highest conductivity. Using p-3MT as the conductive phase, films with conductivity as high as 5.7 Ω⁻¹ cm⁻¹ can be produced, an improvement of four orders of magnitude over previously reported results with Kapton as a base polymer. The highest conductivity achieved using p-PY as the conductive phase was 0.041 Ω⁻¹ cm⁻¹, still a two order of magnitude improvement over previously reported results. Mean mechanical properties of the 3MT-treated films were not significantly lower than that for untreated Kapton. The conductivities of p-3MT/Kapton films tested over time under ambient temperature in air persist fairly well for 300 days. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 63: 821–834, 1997     

High-quality conductive polypyrrole within a secondary crosslinked interpenetrating polymer network

A high-quality conductive polypyrrole was prepared within a secondary crosslinked interpenetrating polymer network by chemical oxidative polymerization, whose conductivity is high up to 0.25 S/cm only with 0.9% polypyrrole. The “microfiber” structure of polypyrrole was characterized by scanning electron microscopy, polarizing microscopy, and small angle X-ray diffraction. The formation of the microfiber was strongly dependent on the structure of the matrix. This might provide a new method for the preparation of conductive microfibers. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 1–4, 1997     

Sulfonated polyurethane anionomer-polypyrrole molecular composite

Preparation of a molecular-level composite of sulfonated polyurethane ionomer and polypyrrole (PUA-PPy) was performed by electrochemical polymerization of pyrrole in aqueous solution of polyurethane anionomer and was confirmed by compositional and Fourier transform infrared analysis. The effects of anionomer concentration and of electrochemical reduction process were followed, and it was forecasted that the composite could behave as a cation exchanger. Some results of thermal analysis were also presented. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 591–595, 1997     

Synthesis of conducting PPy/pTHF copolymers

Living polytetrahydrofuran (pTHF) was terminated with the potassium salt of pyrrole to yield polymers with pyrrole end groups. Copolymerization of THF and pyrrole with short and long pTHF segments was achieved by constant potential electrolysis. Syntheses of the block copolymers were performed using tetrabutylammonium tetrafluoroborate, sodium perchlorate, and sodium p‐toluenesulfonate as the supporting electrolytes. Characterization of the block copolymers were based on scanning electron microscopy, differential scanning calorimetry, thermal gravimetry analysis, cyclic voltammetry, and FTIR studies. No significant effect of the chain length on the properties of the copolymers was observed; however, use of different dopants resulted in different thermal and electrochemical behaviors, surface morphologies, and conductivities. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 713–720, 1999     

Electrochemical study of the uranium exchange by polypyrrole‐based resins

Electrochemical control of the binding of uranium ions by redox active polypyrrole resins was studied. The experimental conditions for this binding were optimized with respect to the uranium ions to be fixed, the resin, and the solution. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 3473–3484, 1999     

原位聚合法制备纳米氧化铬-聚吡咯复合材料

用沉淀法制备了纳米氧化铬（Cr2O3）粉体，对纳米Cr2O3粉体进行表面改性，使其均匀分散到吡咯单体中，采用原位聚合法制备了纳米Cr2O3／聚吡咯（PPy）复合材料。对合成的材料用X射线衍射（XRD）、傅立叶变换红外光谱（FT-IR）和透射电镜（TEM）等方法进行了表征。结果表明：PPy成功包覆在Cr203表面，形成了纳米Cr2O3／PPy复合材料。     

导电高分子纳米复合材料研究进展

介绍了导电高分子纳米复合材料的特点,综述了导电高分子纳米复合材料的最新研究进展,展望了导电高分子纳米复合材料的发展前景。     

Complexation of poly(pyrrole-EDTA like) film modified electrodes: Application to metal cations electroanalysis

Complexing polymer-coated electrodes have been synthesized by oxidative electropolymerization of N,N′-ethylenebis[N-[(3-(pyrrole-1-yl)propyl) carbamoyl) methyl]-glycine] (L). There were used for the electrochemical detection of Cu(II), Pb(II) and Cd(II) ions by means of the chemical preconcentration-anodic stripping technique. For thick polymeric binding materials and long accumulation times, competitive experiments showed that the polyL film modified electrodes are selective towards Cu(II) ions and particularly insensitive to the presence of Cd(II). In contrast, imprinted polymer-coated electrodes prepared by electropolymerization of the Cd(II) complex of L allowed an efficient complexation and sensing of Cd(II) cations. The selectivity of the molecular electrode materials can thus be subtly modulated upon playing on the accumulation time and on the pre-structuration of the complexing polymers.