导电高分子材料的研究与应用现状

主要介绍了聚乙炔、聚吡咯、聚噻吩、聚苯胺、聚对笨乙烯撑这几类导电高分子在近年来的研究进展。综述了提高导电高分子的电导率。改善其溶解性及可加工性的方法，以及导电高分子在电子器件、电池、电磁屏蔽材料、导电橡胶、透明导电膜等方面的实际应用和将来的研究方向。     

PPy/APS-SiO2纳米导电复合材料的合成与表征

用化学氧化聚合复合方法合成聚吡咯／二氧化硅(PPy／SiO2)纳米复合材料。首先用不同百分含量的氨丙基三乙氧基硅烷(APS)处理SiO2，然后以水为反应介质，通过化学聚合方法合成PPy／APS—SiO2纳米复合材料，并利用红外光谱、热失重、X射线光电子能谱(XPS)、透射电镜和四探针等手段进行表征。结果表明，用APS处理过的SiO2合成的复合材料PPy含量增加，且通过XPS看出PPy／APS—SiO2表面富有PPy，而PPy／SiO2表面富有SiO2。其中用1％APS—SiO2合成的复合材料电导率最高，为38．46S／cm。     

纳米银-聚吡咯导电复合薄膜的制备

为研究制备纳米银-聚吡咯(Ag-PPy)导电复合薄膜的最佳聚合工艺,分别采用静置、超声和磁力搅拌三种聚合工艺制备了纳米银-聚吡咯导电复合薄膜。用四探针法测量了复合薄膜的表面电阻值,用三维视频显微镜(3-DVM)观测其表面形貌并测定了膜层的厚度,用X射线衍射仪(XRD)分析了膜层物质的晶型。结果表明:采用频率为25kHz、功率为70 W的超声工艺制备的Ag-PPy导电复合薄膜的综合性能最好,在该条件下得到的复合薄膜表面平整,纳米银粒子在聚吡咯中分布连续且均匀,表面电阻值可达到0.68kΩ,复合物粒子在基体上沉积的厚度为56.28μm,沉积速率为8.67mg·cm-2·h-1。     

Low Temperature Hall Effect Investigation of Conducting Polymer-Carbon Nanotubes Composite Network

Polypyrrole (PPy) and polypyrrole-carboxylic functionalized multi wall carbon nanotube composites (PPy/f-MWCNT) were synthesized by in situ chemical oxidative polymerization of pyrrole on the carbon nanotubes (CNTs). The structure of the resulting complex nanotubes was characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The effects of f-MWCNT concentration on the electrical properties of the resulting composites were studied at temperatures between 100 K and 300 K. The Hall mobility and Hall coefficient of PPy and PPy/f-MWCNT composite samples with different concentrations of f-MWCNT were measured using the van der Pauw technique. The mobility decreased slightly with increasing temperature, while the conductivity was dominated by the gradually increasing carrier density.     

Conductivity and atmospheric aging studies of polypyrrole-coated cotton fabrics

Polypyrrole (PPy) is one of the preferred alternatives among the intrinsically conductive polymers (ICPs). In this study, PPy-coated cotton (PPy-CT) fabrics were synthesized by two step in situ chemical polymerization. The reaction parameters, such as monomer concentration and temperature, were studied in detail. The surface resistivity of PPy-CT fabrics ranged ∼ 15–5000 Ω⁻². To assess long-term usage potential, the atmospheric aging of conductivity characteristics of treated fabrics was monitored over a period of 6 months. It was found that the synthesis temperature had a significant impact on conductivity and atmospheric aging of PPy-CT fabrics. Furthermore, various sulfonic acid sodium salts added as external doping agents during polymerization also had a positive effect. The scanning electron microscopy revealed smoother morphology of sulfonic acid salt doped PPy coatings. The overall study addresses the durability aspect of PPy-CT fabrics in potential applications areas. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Core–shell polypyrrole nanoparticles obtained by atmospheric pressure plasma polymerization

Polypyrrole hollow nanoparticles were prepared by atmospheric pressure plasma polymerization. The structure of the nanoparticles was studied using Fourier transform infrared and X‐ray photoelectron spectroscopies, thermogravimetric analysis, scanning and transmission electron microscopies and atomic force microscopy. In contrast to low‐pressure plasma polymerization of pyrrole, which can produce films and solid nanoparticles, we obtained two types of hollow nanoparticles: a fraction with single spherical core and another with a core composed of small bubbles. Thermal characterization allowed us to determine that the nanoparticles are composed of highly crosslinked polymer. A mechanism that explains the formation of both types of hollow nanoparticles as well as solid nanoparticles is proposed. Chemical characterization shows that, in addition to the expected chemical structures due to pyrrole polymerization, the high energy of the plasma at atmospheric pressure produces intense dehydrogenation and oxidation processes. The fluorescence spectrum of the nanoparticles, however, shows a peak at 482 nm indicating that some degree of π‐conjugation is present in the material. © 2014 Society of Chemical Industry     

Spontaneous and Electrochemical Reduction of Silver by Polypyrrole Deposits

Abstract

Polypyrrole (ppy) coatings doped with p-toluene sulfonate sodium on stainless steel mesh (SSM) have been electrosynthesized in aqueous solution. The removal of Ag⁺ ions from acidic solutions was investigated through spontaneous reduction (SR) and electrochemical reduction (ER) procedures using reduced composite ppy-SSM. Higher removal efficiencies and current efficiencies were obtained by ER process for ppy-SSM rather than SR process for ppy-SSM and ER process for SSM under comparable conditions. Due to its high efficiency and simplicity, ER was supposed to be an alternative advantageous method for the recovery of low-level silver concentration in industrial wastewater. Cyclic voltammetry was carried out to characterize the electrochemical behavior of ppy-SSM in acid solutions containing Ag⁺. Metallic silver deposited on ppy-SSM has been evidenced by scanning electron microscopy (SEM) analysis.     

CuBr2‐induced charge screening on photoactive nanocolloidal polypyrrole:poly(styrene sulfonate) composite multilayer thin‐film counter electrodes for high‐efficiency dye‐sensitized solar cells

Nanocolloidal polypyrrole (PPy):poly(styrene sulfonate) (PSS) particles were synthesized by chemical oxidative polymerization using 15 wt% of PSS. The highly processable polymer composite (PPy:PSS) was spin‐coated at 4000 rpm on fluorine‐doped tin oxide glass and subsequently employed as a counter electrode (CE) for dye‐sensitized solar cells (DSCs). PPy:PSS multilayer (one, three, five) CEs were treated with CuBr₂ salt, which enhances the efficiency of the DSCs. Optical studies reveal that a bulkier counterion hinders interchain interactions of PPy which on salt treatment shows a moderate redshift in absorption maxima. Salt‐treated PPy:PSS films exhibit lower charge transfer resistance, higher surface roughness and better catalytic performance for the reduction of I₃^?, when compared with untreated films. The improved catalytic performance of salt‐treated PPy:PSS multilayer films is attributed to charge screening and conformational change of PPy, along with the removal of excess PSS. Under standard AM 1.5 sunlight illumination, salt treatment is shown to boost the efficiency of multilayer PPy:PSS composite film‐based DSCs, leading to enhanced power conversion efficiency of 6.18, 6.33 and 6.37% for one, three and five layers, respectively. These values are significantly higher (ca 50%) than those for corresponding devices without CuBr₂ salt treatment (3.48, 2.90 and 2.01%, respectively). © 2016 Society of Chemical Industry     

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。