掺杂态和本征态聚苯胺对不锈钢的保护作用

Protection Performance of Doped and Eigenstate Polyaniline on Stainless Steel

用电化学方法在不锈钢表面制备了磷酸掺杂的聚苯胺,将掺杂态聚苯胺浸在1mol/L氨水中脱掺杂得到本征态聚苯胺。用扫描电子显微镜和红外光谱对掺杂态和本征态聚苯胺进行了表征,采用动电位极化曲线和电位-时间曲线研究了它们对不锈钢在1mol/L硫酸钠溶液中的保护性能。结果表明,掺杂态和本征态聚苯胺表面都有孔,使不锈钢的自腐蚀电位显著正移;本征态聚苯胺起机械隔离作用,掺杂态聚苯胺主要使不锈钢钝化;掺杂态聚苯胺对不锈钢的保护时间比本征态的长很多。

Polyaniline（Pani） doped with phosphoric acid was synthesized on stainless steel by electrochemical method and the eigenstate Pani was prepared by immersing the doped Pani in 1 mol/L NH_4OH for 4h.The doped pani and eigenstate Pani were characterized by scanning electron microscopy and fourier transform infrared spectroscopy.Their protection performance on stainless steel in 1 mol/L Na_2SO_4 solution was investigated through potentiodynamic polarization and potential-time curves.Results indicated that there were holes on both surfaces of the doped and eigenstate Pani.The corrosion potential of both kinds of Pani positively shifted remarkedly.The eigenstate Pani protects stainless steel by mechanical isolation.The doped Pani protects stainless steel by passivation,and its protection time is longer than that of the eigenstate Pani.