碳钢表面导电PEDOT涂层的电化学制备及防腐性能  

Electrochemical Preparation and Corrosion Resistance of Conductive PEDOT Coating on Carbon Steel Surface

作　　者：高博文 王美涵[1] 闫茂成[2] 雷浩[3] GAO Bo-wen;WANG Mei-han;YAN Mao-cheng;LEI Hao(School of Mechanical Engineering,Shenyang University,Shenyang 110044,China;National Institute of Metal Corrosion Control Engineering,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China;Laboratory of Metal Corrosion and Protection,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China)

机构地区：[1]沈阳大学机械工程学院,沈阳110044 [2]中国科学院金属研究所国家金属腐蚀控制工程技术研究中心,沈阳110016 [3]中国科学院金属研究所金属腐蚀与防护实验室,沈阳110016

出　　处：《表面技术》2020年第9期298-305,共8页Surface Technology

基　　金：中国科学院A类战略性先导科技专项(XDA13040500);国家重点基础研究发展计划(2014CB643304);辽宁省高等学校创新人才支持计划(LR2019044);沈阳市中青年科技创新人才支持计划(RC190359)。

摘　　要：目的在Q235钢基底上电沉积致密导电聚合物PEDOT涂层,利用PEDOT的良好导电性,避免电荷集中,提高Q235钢的防腐性能。方法在十二烷基硫酸钠(SDS)和高氯酸锂(LiClO4)溶液中,通过电化学恒电流方法在Q235碳钢基底上电聚合EDOT。采用循环极化、开路电位监测(OCP)、电化学阻抗谱(EIS)及扫描振动电极(SVET)等手段,研究导电PEDOT涂层与碳钢基底的电化学交互作用及其对基底腐蚀行为的影响规律。结果在电流密度为5 mA/cm^2的条件下,沉积的PEDOT涂层最完整、致密,具有球状团聚表面形貌。PEDOT/Q235电极在3.5%NaCl溶液中浸泡40 h后电偶电流密度为-15μA/cm^2,电偶电压为-715 mV。多次循环极化曲线基本重合,体现出良好的电化学稳定性。开路电位和EIS结果表明,PEDOT涂层4 d后钝化了基底,对基底产生保护。SVET结果证明,PEDOT涂层能够形成电子离域,避免电荷集中,涂层划痕区的电流密度从628μA/cm^2降低到23.8μA/cm^2。结论PEDOT涂层可以减轻Q235基底在NaCl溶液中的腐蚀,其减缓腐蚀的能力归因于其结构致密、钝化基底及减少表面电荷集中。The work aims to improve the corrosion resistance of Q235 carbon steel by electro-depositing compact PEDOT coatings on it,so as to avoid charge concentration by the good conductivity of PEDOT.EDOT was electropolymerized on a Q235 carbon steel substrate by electrochemical galvanostatic method in sodium dodecyl sulfate(SDS)and lithium perchlorate(LiClO4)solution.Electrochemical interaction between conductive PEDOT coatings and carbon steel substrate as well as the effect laws on corrosion behavior of Q235 carbon steel were investigated by cyclic polarization,open circuit potential monitoring(OCP),electrochemical impedance spectroscopy(EIS)and scanning vibrating electrode technology(SVET).At a current density of 5 mA/cm^2,the as-deposited PEDOT coatings were the most complete and compact,with agglomerated spherical surface morphology.The coupling current density of the PEDOT/Q235 electrode after 40 h immersion in 3.5wt%NaCl solution was-15μA/cm^2,and the coupling voltage was-715 mV.The multiple cyclic polarization curves of PEDOT/Q235 were almost repeated,showing good electrochemical stability.The OCP and EIS results indicated that the PEDOT coatings passivated the Q235 substrate after 4 days,protecting the substrate.The SVET demonstrated that electron delocalization was formed on the PEDOT coatings,avoiding charge concentration resulting in the reduction of the current density in the scratch zone from 628μA/cm^2 to 23.8μA/cm^2.PEDOT coatings can alleviate the corrosion of Q235 substrate in NaCl solution,which is attributed to the dense structure,the passivation of substrate and the reduction of surface charge concentration.

关 键 词：PEDOT涂层 Q235钢 恒电流 电化学 SVET 

分 类 号：TG174.4[金属学及工艺—金属表面处理]