掺杂聚吡咯涂层合成及其对铜防腐蚀性能研究

Synthesis of Polypyrrole Coatings Doped with Anion and its Anticorrosion Property for Copper

采用循环伏安法在铜基底表面沉积了氯掺杂修饰和未掺杂的聚吡咯涂层。通过傅里叶红外变换光谱与扫描电子显微镜测试涂层的结构和形貌,结果显示氯掺杂聚吡咯具有最佳的致密度。由极化曲线、开路电位-时间曲线和电化学阻抗谱研究聚吡咯涂层在模拟质子交换膜燃料电池工作环境中对铜的腐蚀防护作用,发现氯掺杂聚吡咯和未掺杂聚吡咯涂层分别使铜自腐蚀电位正移动93和70 mV,聚吡咯涂层腐蚀电流密度下降一个数量级;研究过程中,未掺杂聚吡咯涂层开路电位较氯掺杂聚吡咯涂层低但高于基体,两种涂层长时间浸泡后皆有向基体接近的趋势,但氯掺杂聚吡咯始终保持较高的开路电位,表明通过氯离子掺杂修饰的聚吡咯涂层较未掺杂的涂层能够更好的对铜提供腐蚀防护作用。

The polypyrrole coating doped with Cl-(Cl-ppy)was electrodeposited by using cyclic voltammetry on copper, with the reference of non-doping coating(nd-ppy). SEM and FTIR are used to explain molecular structures and morphology of coatings. The results show that the compactness of the Cl-ppy is better compared with nd-ppy. The corrosion performance that simulated the working in the atmosphere of PEMFC was discussed by polarization, open-circuit potential measurement and electrochemical impedance spectroscopy(EIS). The two coatings were found with certain protection function. Cl-ppy and nd-ppy make copper’s corrosion potential respective moved the 93 and 70 mV, and the corrosion current density with doping coatings is an order of magnitude decline. The open circuit of nd-ppy is low then Cl-ppy, and Cl-ppy keeps higher open circuit potential, show that Cl ion doped in Ppy coating could improve the protective performance of copper.