1-乙基-3-甲基咪唑硫酸乙酯盐离子液体中采用电化学法合成聚苯胺薄膜及其耐蚀性  

Electrosynthesis of Polyaniline Film in a 1-ethyl-3-methylimidazole SulfateIonic Liquid and Its Corrosion Resistance

作　　者：周婉秋 赵玉明 刘晓安 杨佳宇 姜文印 辛士刚 康艳红 ZHOU Wanqiu;ZHAO Yuming;LIU Xiao’an;YANG Jiayu;JIANG Wenyin;XIN Shigang;KANG Yanhong(College of Chemistry and Chemical Engineering,Shenyang Normal University,Shenyang 110034,China)

机构地区：[1]沈阳师范大学化学化工学院,沈阳110034

出　　处：《材料导报》2020年第12期12152-12157,共6页Materials Reports

基　　金：辽宁省教育厅重点实验室基础研究项目(LZ2015066)。

摘　　要：为了进一步扩大质子交换膜燃料电池(PEMFC)的实际应用,提高其双极板的耐腐蚀性能至关重要。在不锈钢基体上电化学沉积导电聚苯胺(PANI)薄膜,有可能满足PEMFC对导电性和耐蚀性的要求。前人关于电化学合成PANI主要集中在硫酸、高氯酸等水溶液体系,鲜见离子液体中采用电化学法合成聚苯胺薄膜及其耐蚀性的研究。本工作以1-乙基-3-甲基咪唑硫酸乙酯盐(EMIES)离子液体作为聚合反应电解质,采用循环伏安法在316L不锈钢(SS)表面电化学合成PANI薄膜,制备了PANI/316L SS复合材料双极板。用红外光谱、拉曼光谱、紫外可见光谱、X射线光电子能谱和扫描电子显微镜对PANI膜进行结构表征,用开路电位、极化曲线和电化学阻抗谱研究PANI/316L SS腐蚀性能。结果表明:PANI具有中间氧化态结构,EMIES离子液体的阴离子(CH 3CH 2SO 4-)和乙二酸的阴离子(HOOC-COO-)作为“对阴离子”在PANI共轭分子链中发生了共掺杂。本工作在316L SS表面获得了平整致密的PANI薄膜。与316L SS裸金属相比,PANI/316L SS的腐蚀电位E 0提高0.2~0.4 V,腐蚀电流密度I 0降低一个数量级,PANI薄膜使316L SS耐腐蚀性能显著增强。To expand the practical application of proton exchange membrane fuel cell(PEMFC),it is important to improve the corrosion resistance of its bipolar plate.Electrochemical deposition of conductive polyaniline(PANI)films on stainless steel(SS)substrate may meet the requirements of PEMFC for conductivity and corrosion resistance.Previous studies on electrochemical synthesis of PANI mainly focused on aqueous systems such as sulfuric acid and perchloric acid,and few studies involved in electrosynthesis of PANI films in ionic liquids and their corrosion resistance.In this work,PANI films were synthesized by cyclic voltammetry on the surface of 316L SS using 1-ethyl-3-methylimidazole ethyl sulfate(EMIES)ionic liquid as the polymerization electrolyte,and the PANI/316L SS composite materials bipolar plates were prepared.The structure of PANI was characterized by infrared spectrum,Raman spectroscopy,ultraviolet-visible spectrum,X-ray photoelectron spectrum and scanning electron microscope.The corrosion performance of PANI/316L SS was studied by open circuit potential,polarization curve and electrochemical impedance spectroscopy.The results show that PANI has an intermediate oxidation state structure,the anion of the ionic liquid EMIES(CH 3CH 2SO 4-)and the anion of oxalic acid(HOOC-COO-)as“counter anion”are co-doped in PANI conjugated molecular chains.A flat and compact PANI film is obtained on the surface of 316L SS.Compared with 316L SS bare metal,the corrosion potential E 0 of PANI/316L SS increases by 0.2—0.4 V,and the corrosion current density I 0 decreases by an order of magnitude.PANI film improves the corrosion resistance of 316L stainless steel obviously.

关 键 词：双极板 聚苯胺薄膜 离子液体 掺杂 耐蚀性 

分 类 号：TG174.4[金属学及工艺—金属表面处理]