Polyaniline and polypyrrole oxygen reversible electrodes

The effect of oxygen on the potential of reduced forms of polyaniline and polypyrrole were investigated. These forms of polyaniline and polypyrrole were not stable in the presence of oxygen. Zinc–polyaniline, zinc–polypyrrole, polyaniline–polyaniline (PANI–PANI), and polypyrrole–polypyrrole (PPy–PPy) batteries were constructed and studied. The effect of oxygen on the short-circuit current of these batteries showed that the cathode material, i.e., polyaniline and polypyrrole, can be regenerated by oxygen oxidation after discharge. These materials are potential candidates for the use as O₂ “fuel cell” type electrocatalytic electrodes.     

Electrodeposition of metals after cation-exchange on modified carbon fibre electrodes

Several metals, Ag, Cu, Pb, Hg and Au, have been electrodeposited on carbon fibre electrodes after cation exchange of their salts with the acidic functional groups of oxidized fibres.Oxidation of carbon fibres was performed by thermal, photochemical and electrochemical treatment. The uptake of the metal cations is greater in the case of anodically oxidized and partially re-reduced carbon fibres, since this procedure leads to the formation of functional groups not only on the carbon surface, as in the case of thermal or photochemical oxidation, but also in the bulk of the fibres.The above-mentioned metals are deposited on the carbon support in a highly dispersed state, which decreases the hydrogen overvoltage and catalyses the reduction of nitroalkanes. These reactions take place on the metal-modified carbon electrodes at much more positive potentials than on carbon and at slightly more positive potentials than on the respective plain metallic electrodes.     

Relaxation behavior of latex polymers modified by water-soluble dyes. Negative temperature range

The effect of a water-soluble blue indanthrene-type dye on the relaxation structure of styrene–acryl latex with the glass transition point of ≤5°C is studied using the method of dynamic mechanical relaxation spectroscopy. Variation of intensity of the maximum of α-relaxation dissipation losses in the latex polymer is observed, same as its relationship to the mechanism of modification of the polymer film by a dye. Special attention is paid to relaxation effects in the negative temperature range.     

Electrocatalytic reactions on carbon fibre electrodes modified by hemine II. Electro-oxidation of hydrazine

The electrocatalytic oxidation of hydrazine on pristine and on electro-oxidized carbon fibre electrodes modified by hemine is investigated in aqueous, methanolic and acetonitrile solutions.

The catalytic activity of the modified electrodes is attributed to the hemine monomers which, according to the mechanism proposed, form an intermediate adduct with hydrazine.

Hydrazine electro-oxidation produces nitrogen in aqueous and methanolic solutions, whereas in acetonitrile only one-third of the molecules are oxidized to the corresponding diimide.

The electro-oxidation of the fibers by potentiostatic double-pulse application provides a substrate that has an effective area four times that of the pristine fibres and enhances an analogous catalytic efficiency. The electro-oxidized fibres bear a large number of active functional groups, which cause chemical oxidation of hydrazine in methanolic and acetonitrile solutions.     

Electrocatalytic reactions on carbon fibre electrodes modified by hemine I. Electroreduction of oxygen

The electrocatalytic reduction of oxygen on pristine and on electro-oxidized carbon fibre electrodes modified by hemine is investigated in aqueous, methanolic and acetonitrile solutions.

The attached iron porphyrin on the modified electrodes exists in two forms, monomeric and dimeric, the latter consisting of two Fe(III)-protoporphyrin molecules held together with an oxygen atom. The catalytic activity of the electrodes is attributed to the hemine monomers, which have the ability to bond the O₂ molecule at the axial position of the metal ion of the porphyrin.

The catalytic reduction of O₂ in acidic aqueous and methanolic solutions produces H₂O, whereas in acetonitrile H₂O₂ is formed.

The electro-oxidized modified electrodes show a catalytic efficiency four-times greater than the pristine electrodes, which is consistent with the analogous increase of the effective electrode area after the electro-oxidation procedure.     

The photoelectrochemical properties of TiO2 electrodes modified by quantum sized PbS and thiols

Photoelectrochemical electrodes have been prepared by chemical deposit of quantum sized PbS particles (Q-PbS) on TiO₂ nanocrystalline films and followed by the modification of such electrodes with thiols. The photoelectrochemical properties have been studied. The results show that Q-PbS modified TiO₂ electrodes generate photocurrent as high as 542.5 μA/cm² under irradiation of a 400 nm light, but it undergoes photodegradation. The modification with thiols leads to an improvement in terms of increased photostability, although the photocurrent decreases due to the resistance brought about by the carbon chains of thiols.     

Polyaniline as an electrode material for magnesium reserve battery

The results of the investigation on the use of polyaniline (PANI) as a cathode material in a battery configuration, having magnesium as anode and a neutral aqueous solution of one of the magnesium salts such as perchlorate, chloride and bromide as an electrolyte, are presented. This system shows a open circuit voltage in the range 1.6-1.8 V. The study indicates that the capacity of the system largely depends upon the anion present in the electrolyte.     

二次掺杂聚苯胺的防腐蚀性能

采用不同的功能质子酸对化学氧化法合成的聚苯胺进行二次掺杂,比较了不同掺杂态聚苯胺的溶解性能;采用开路电位法和极化曲线法考查聚苯胺/环氧复合涂膜的防腐蚀性能。结果表明,用十二烷基苯磺酸钠(DBSA)掺杂的聚苯胺涂料具有很好的防腐蚀性能,涂覆该涂料的平衡开路电位比空白试样提高了近100 mV。     

聚苯胺防腐蚀涂料的研究现状

概述了国内外聚苯胺防腐蚀涂料的研究情况,具体涉及聚苯胺的结构、性能和聚苯胺防腐蚀涂层的制备方法;介绍了聚苯胺涂层的作用原理和应用情况;提出了聚苯胺的研究方向、具体研究内容及方法。     

Polyaniline and multi-walled carbon nanotube composite electrode for rechargeable battery

The multi-walled carbon nanotube was introduced into the polymer matrix (PANI) to improve the electric conductivity as well as mechanical properties of the original polymer matrix.PANI/multi-walled carbon nanotube (MWCNT) composites were synthesized via ex-situ and in-situ polymerization to improve their electrical property.And the DC conductivities of PANI/MWCNT according to content and diameter of MWCNT were measured by four-point probe.The highest electric conductivity of PANI/MWCNT composite is 20 S/cm when 0.3% (mass fraction) MWCNTs with 10 nm in diameter and 15 μm in length are added in composite.     

聚苯胺防腐涂料的研究现状

对国内外聚苯胺防腐涂料的研究现状进行了概述,包括聚苯胺的结构和性能、目前制备聚苯胺防腐涂层的3种主要方法,并比较了3种方法的特点.对聚苯胺防腐涂料的防腐性能与防腐机理进行简单介绍,并指出了聚苯胺防腐涂料下一步应开展的工作.     

热作模具钢堆焊焊条的研制

对3Cr3Mo3W2V焊条的药皮组成、堆焊工艺、堆焊层组织进行了探讨。焊条焊芯采用3Cr4Mo2V1的φ4mm焊丝，并在药皮中加入了钨粉、钼铁，向堆焊层中过渡钨和钼合金元素，以获得与3Cr3Mo3W2V相近的化学成分。结果表明：采用所研制的焊条堆焊，经热处理基本达到3Cr3Mo3W2V热作模具的工作要求。     

A visible-light-assisted Pd/TiO2 gas sensor with carbon nanotubes electrodes for trace formaldehyde detection

Owing to the ppb-level detection standard toward the toxic and harmful gas, the detection of trace gases has become an important subject in the field of indoor environment management. However, the traditional resistive gas sensors hardly meet the requirement due to the weak signal generated by trace gas molecules that are difficult to capture. Herein, a visible-light-assisted Pd/TiO₂ gas sensor is proposed to endow the effective detection of trace formaldehyde(HCHO) gas without heatin...     

镁合金表面聚苯胺膜层防腐性能的研究

用循环伏安法在镁合金表面制备了聚苯胺膜层,并用扫描电子显微镜(SEM)和电极电位研究了聚苯胺膜的表面形貌和腐蚀防护性能.研究表明:聚苯胺膜层并不是均匀覆盖在基体表面,而且膜层表面存在很多的微孔;聚苯胺改变了膜层的电极电位;在腐蚀介质中聚苯胺膜以点蚀或剥离的方式进行腐蚀.     

Synthesis and Characterization of Reduced Graphene Oxide- Polyaniline Composite for Supercapacitor Applications

Graphene oxide (GO) is synthesized from commercially available graphite powder. The prepared GO is converted to reduced graphene oxide (rGO) by chemical reduction using sodium borohydride and sodium hydroxide. The rGO is characterized via X-ray diffraction, Raman spectroscopy and scanning electron microscopy. Conducting polymer–polyaniline, was prepared by oxidative polymerization in an electrolyte- hydrochloric acid and using ammonium persulphate as oxidant. The structure and doping of polyaniline were studied by Fourier-transform infrared spectroscopy and ultra-violet visible spectroscopy. To enhance the conductivity of the rGO, the conducting polymer mixed with rGO and rGO/Conducting polymer composites were prepared. The composite was characterized by cyclic voltammetry, AC impedance spectroscopy. A symmetrical supercapacitor (SC) has been fabricated based on rGO/PANI composites. The prepared composites were shown specific capacitance of 72 F g^–1 at 2 mV s^–1.     

聚苯胺在防腐方面的研究及应用现状

聚苯胺(PANI)具有良好的热稳定性和环境稳定性,经掺杂后,具有导电性及电化学性,可作为填料应用于金属防腐领域。但其分子链骨架刚性强、分子间作用力大,不易加工成型,不溶于常规的有机溶剂,当其作为填料应用到防腐涂料中存在溶解性、分散性差且与金属基底附着力不强等缺点,如能对其进行合理有效的改性,则可解决上述问题。简要探讨了溶液聚合法、反相微乳液聚合法、模板聚合法以及电化学聚合法等PANI的制备方法,并针对PANI在防腐涂料应用中存在的问题,重点阐述了PANI的质子酸掺杂改性及复合改性等不同改性方法,通过掺杂不同的质子酸对PANI进行化学改性,可降低PANI分子链之间的相互作用,从而提高其溶解性、导电性和防腐性能。将不同性能的材料与PANI进行复合改性,改善分子间作用力,能提高其加工性,从而更好的应用于金属的腐蚀防护工作。最后介绍了PANI在腐蚀防护过程中的作用、在防腐蚀涂料中的应用及相关理论的研究现状,并指出PANI防腐涂层的研究重点和发展方向。     

一种新型聚苯胺涂层的防腐蚀性能

在酸性环境下用化学氧化法合成了聚苯胺;制备了不同含量的本征态和掺杂态聚苯胺涂覆的碳钢试样,利用塔菲尔曲线比较了它们在质量分数为3.5%的NaCl和1 mol/L HCl溶液中的腐蚀行为.结果表明:当间甲酚固化剂作为溶剂、磷酸作为催化剂时,本征态聚苯胺涂层具有良好的防腐蚀性能;不同状态聚苯胺的防腐蚀性能与腐蚀介质有关,与聚苯胺的含量有关.     

Aging of Water-Soluble Formulations for Inkjet Printing of Functional Layers Based on Polyaniline

Protection of Metals and Physical Chemistry of Surfaces - The process of aging of water-soluble formulation based on polyaniline with poly(2-acrylamido-2-methyl-1-propanesulfonic acid) complex was...     

Double-activated porous carbons for high-performance supercapacitor electrodes

The double-activated porous carbons(DAPCs)with unique bimodal pore structure were prepared by activating commercial microporous carbon(CMCs) twice through KOH(double activation) at high temperature. The as-prepared DAPCs show larger surface area(833 m~2·g~(-1)),and the pores are composed of micropores(size of~1.8 nm) and mesopores(size of ~4.5 nm). Such special hierarchical porous structures integrate the dual advantages of micropore and mesopore, having not only the high energy storage of the micropores but also the high-rate performance of the mesopores for supercapacitors(SCs).As a result, the optimized DAPCs-3-1 exhibits a high specific capacitance of 277 F·g~(-1) at 1 A·g~(-1), enhanced rate performance of 197 F·g~(-1) at a high current density of 10 A·g~(-1), and excellent cycling stability with 94.2% capacity retention after 10,000 cycles in the 1 mol·L~(-1) Na_2SO_4 electrolyte. The facile double activation could be a promising method to prepare suitable porous carbons with exceptional electrochemical properties for SCs.