Raman and UV–vis spectroscopic study of polyaniline membranes containing a bulky cationic additive

Electrically conducting soluble polyaniline (PANI), containing different amounts of a bulky lipophilic cationic additive, tridodecylmethylammonium chloride (TDMACl), was studied by Raman (λ_exc=780 nm) and UV–vis spectroscopy. PANI was made simultaneously electrically conducting and soluble with bis[4-(1,1,3,3-tetramethylbutyl)phenyl]phosphoric acid in dichloromethane. The PANI membranes were prepared by drop casting on glassy carbon or ITO substrates. Raman and UV–vis measurements were carried out in a 0.1 M CaCl₂ solution at potentials between 400 and ?600 mV (vs. SCE) at pH 6, or alternatively at the open circuit potential at pH 10. The results of Raman, UV–vis and cyclic voltammetric measurements confirm that the incorporation of TDMACl into the PANI membrane facilitates the oxidation and reduction of PANI.     

聚苯胺/聚合物导电材料研究进展

从制备方法着手综述了近年来聚苯胺/聚合物导电材料研制开发的最新成果，并简介了聚苯胺/聚合物导电材料的应用情况。     

聚苯胺在防腐领域的应用

综述导电聚苯胺用于金属防腐蚀领域的最新进展,并且探讨了其相关的防腐机理。     

Beneficial effect of aligned nanofiber scaffolds with electrical conductivity for the directional guide of cells

Abstract

Conducting polymer-based scaffolds receive biological and electrical signals from the extracellular matrix (ECM) or peripheral cells, thereby promoting cell growth and differentiation. Chitin, a natural polymer, is widely used as a scaffold because it is biocompatible, biodegradable, and nontoxic. In this study, we used an electrospinning technique to fabricate conductive scaffolds from aligned chitin/polyaniline (Chi/PANi) nanofibers for the directional guidance of cells. Pure chitin and random and aligned Chi/PANi nanofiber scaffolds were characterized using field emission scanning electron microscope (FE-SEM) and by assessing wettability, mechanical properties, and electrical conductivity. The diameters of aligned Chi/PANi nanofibers were confirmed to be smaller than those of pure chitin and random nanofibers owing to electrostatic forces and stretching produced by rotational forces of the drum collector. The electrical conductivity of aligned Chi/PANi nanofiber scaffolds was ~91% higher than that of random nanofibers. We also studied the viability of human dermal fibroblasts (HDFs) cultured on Chi/PANi nanofiber scaffolds in vitro using a CCK-8 assay, and found that cell viability on the aligned Chi/PANi nanofiber scaffolds was ~2.1-fold higher than that on random Chi/PANi nanofiber scaffolds after 7 days of culture. Moreover, cells on aligned nanofiber scaffolds spread in the direction of the aligned nanofibers (bipolar), whereas cells on the random nanofibers showed no spreading (6 h of culture) or multipolar patterns (7 days of culture). These results suggest that aligned Chi/PANi nanofiber scaffolds with conductivity exert effects that could improve survival and proliferation of cells with directionality.     

不同掺杂酸对纤维聚苯胺电化学性能的影响

采用界面聚合法通过不同质子酸掺杂分别制备了平均直径约为50,62,95 nm的纤维聚苯胺。通过傅里叶变换红外光谱(FT-IR)、扫描电子显微镜(SEM)、透射电镜(TEM)对其化学组成和微观形貌进行了表征,采用循环伏安、恒流充放电和交流阻抗研究了不同质子酸掺杂纤维聚苯胺的超级电容器电容行为,并利用X射线衍射(XRD)、氮气吸脱附及X射线光电子能谱(XPS)等方法对纤维聚苯胺的微观结构进行了深入研究。结果表明：高氯酸(HClO4)掺杂制备的聚苯胺在0.5 A/g电流密度下的比容量可以达到397 F/g,高于盐酸(HCl, 334 F/g)和樟脑磺酸(HCSA, 383 F/g)掺杂聚苯胺的测试结果,纤维的电化学性能主要受其规整度、孔隙率及掺杂度的影响。     

Preparation and Characterization of Graphene Oxide/Polyaniline/Carbonyl Iron Nanocomposites

Nano coatings for anti-corrosion and electromagnetic wave absorbing can simultaneously implement the functions of assimilating electromagnetic waves and reducing the corrosion of materials caused by corrosive environments, such as seawater. In this work, a composite material for both electromagnetic wave absorption and anti-corrosion was prepared by an in-situ chemical oxidation and surface coating method using carbonyl iron powder (CIP), graphene oxide (GO) and aniline (AN). The synthesized composite material was characterized by scanning electron microscopy (SEM), infrared spectroscopy (FT-IR) and XRD. The carbonyl iron powder-graphene oxide-polyaniline (CIP-GO-PANI) composite material was used as the functional filler, and the epoxy resin was the matrix body for preparing the anticorrosive wave-absorbing coating. The results show that CIP had strong wave-absorbing properties, and the anti-corrosion property was greatly enhanced after being coated by GO-PANI.     

掺杂条件对聚苯胺膜导电性能影响的研究

采用对甲基苯磺酸和磺基水杨酸作掺杂剂，对聚苯胺自支撑膜进行了掺杂研究，考查了掺杂时间，温度以及掺杂溶液浓度对其导电性的影响，并用红外光谱及显色反应对掺杂产物进行了表征。结果表明，掺杂温度对聚苯胺膜电导率的影响较大，通过控制温度，可以制备出电导率达盐酸掺杂水平的导电膜，即－１０＾３Ｓ．ｍ＾－１，且具有良好的环境稳定性，在空气中放置一年，其电导率基本保持不变。     

Synthesis of Conducting Polymer Spiral Nanostructures Using a Surfactant Crystallite Template

The present work describes, for the first time, the synthesis of spiral nanostructures of conducting polymers by chemical oxidant polymerization using a hydrated surfactant (sodium dodecyl sulfonate (SDSn)) crystallite template. A spiral dislocation structure on the surface of a hydrated SDSn crystallite has been observed and is responsible for the growth of the spiral nanoarchitecture of conducting polymers (polypyrrole, polyaniline). Ammonium peroxydisulfate (APS) has a strong tendency to induce the formation of a spiral dislocation structure of hydrated SDSn crystallites. The mechanism of adsorption of pyrrole or aniline oligomers on the steps of dislocation is proposed for the growth of conducting polymer spirals.

     

聚苯乙烯磺酸掺杂聚苯胺的合成

以苯胺（An）为单体，过硫酸铵（APS）为氧化剂，在聚苯乙烯磺酸（PSSA）的水溶液中，合成了可完全溶于水的PSSA掺杂PAn。研究了An浓度，PSSA浓度，APS浓度，APS的滴加时间，反应时间及温度对An聚合反应及其产物的水溶性，导电性及特性粘度[η]的影响。结果表明：在比较宽的实验条件下，都可以合成出具有良好导电性的可溶于水的PSSA掺杂PAn；其中当An：PSSA:APS的摩尔比为1．7：2．5：1，APS溶液的滴加时间为3h，反应时间为1h，反应温度为14℃时，得到的掺杂PAn导电率最高达0．156S／cm。     

Synthesis of Polyanilines Bearing Optically Active Substituents

Summary: Optically active polyanilines were prepared by an interfacial polymerization with (NH₄)₂S₂O₈ in a water/perchloric acid/chloroform system. The pristine polymer obtained in this way is in the oxidized (doped) form. The polymers display the mirror‐image Cotton effect. The doping process in solution allows a change in the circular dichroism of the polymer. The procedure has great potential in the improved preparation of durable optoelectrical devices based on the good film‐forming properties of chiral polymers.

CD spectra of R ‐ P2 (solid line) and S ‐ P2 (dashed line) in 4.0 × 10^?4 M THF solution.