双极性涂层浸泡过程的电化学阻抗谱行为

摘要

制备了仿金属钝化膜的双极性环氧基有机涂层.测试了双极性环氧基涂层/16Mn体系在50%KCl溶液中的电化学阻抗谱,以研究该体系的性能及失效过程.结果表明,在浸泡初期,由于双极性环氧基有机涂层离子选择性,能有效阻止或抑制腐蚀性介质的浸人;随浸泡时间的延长,在阴阳膜层的结合处形成"空间电荷区"或"耗尽层",对金属腐蚀的防护起关键作用.%An epoxy-based bipolar coating was prepared and the electrochemical behavior of the epoxy-based bipolar coating/16Mn system immersed in 5％ KCl solution was studied by electrochemical impedance spectroscopy (E IS). The results showed that at the first stage the coating could prevent the penetration of corrosive media effectively,because of its ionic selectivity. With the immersion time prolonged, the space charge region or depletion layer formed at the boundary of the anion-selective and cation-selective unipolar membranes could inhibit the metal corrosion.