摘要：本论文研究了导电聚合物涂层作为交换膜燃料电池(PEMFC)铜双极板的表面抗腐蚀涂层的抗腐蚀性能，对比研究了以对甲苯磺酸(ToSH)为掺杂剂的吡咯溶液以及没有掺杂剂的吡咯溶液中，采用循环伏安法在铜电极表面聚合得到聚吡咯(Ppy)涂层。讨论了掺杂剂的用量，结果表明在掺杂0.1MToSH的0.2MPpy+0.2MH2C2O4电沉积溶液中效果最佳。采用红外光谱(IR)、扫描电子显微镜(SEM)等表面分析方法对导电聚合物涂层特征进行表征，表明掺杂Ppy涂层由小颗粒紧密排列而成，外观光亮、平整。未掺杂Ppy涂层局部致密但不平整，出现少量空隙与裂缝。采用动电位极化、开路电位-时间曲线以及电化学阻抗谱(EIS)等电化学测量技术评价所制涂层的耐蚀性能，表明两种方法制备的Ppy涂层对铜基体都有很好的防护性能，其中未掺杂Ppy涂层使得铜基体自腐蚀电位正移了61mV，腐蚀电流密度从10-4A/cm2下降到10-5A/cm2；而掺杂Ppy膜使得基体自腐蚀电位正移了76mV，腐蚀电流密度从10-4A/cm2下降到10-5A/cm2。这是由于未掺杂涂层存在微缺陷，而掺杂涂层相对致密，涂层对基体的保护时间更长，耐蚀性能更好。
关键词： 聚吡咯，对甲苯磺酸，掺杂，腐蚀
Abstract:In this research, corrosion resistance of the conductive polymer coating as the surface anti-corrosion coating of the copper bipolar plate of the exchange membrane fuel cell (PEMFC) was studied, comparing the pyrrole solution with p-toluenesulfonic acid (ToSH) pyrrole as the dopant with the pyrrole solution without p-toluenesulfonic acid (ToSH) pyrrole. The poly pyrrole coating of the surface of the copper electrode was got by using the cyclic voltammetry polymerization . The amount of dopant was discussed. It was resulted that 0.2Mpy +0.2 MH2C2O4 power deposition solution with 0.1MtoSH was the best . the conductive polymer coating characteristics were characterized by Infrared spectroscopy (IR), scanning electron microscopy (SEM) and other surface analysis methods . It showed that the coating doping PPy was consisted of closely arranged small particles in bright and smooth appearance. The coating undoping PPy was dense locally but not flat. A little of gaps and cracks were appeared . By using the electrochemical measurements techniques , such as potentiodynamic polarization, open circuit potential - time curves and electrochemical impedance spectroscopy (EIS) , the corrosion resistance of the coating was evaluated. It showed that Ppy coating ,Prepared by two methods has a good protective performance to the copper substrate. The corrosion potential of the copper substrate with Undoped Ppy coating shifted 61mV positively, and the corrosion current density decreased from 10-4A/cm2 to 10-5A/cm2. The corrosion potential of the substrate with the Ppy membrane, synthesized by cyclic voltammetry, shifted 76mV positively, the corrosion current density decreased from 10-4A/cm2 to 10-5A/cm2. This is due to that the undoped coating has the micro-defects , while the doped coating is relatively dense, the protection time of coating on the substrate is longer, and corrosion resistance is better.
Key words : Ppy, ToSH, Doping, Corrosion
