采用恒电流和循环伏安法(CV)在金属钛表面电沉积聚吡咯(PPy)涂层,并通过SEM和FTIR对所制备的膜形貌和结构进行表征。在弱酸性环境中采用动电位极化、开路电位-时间曲线和交流阻抗等技术研究比较了聚吡咯涂层对钛金属抗腐蚀性能。结果发现,2种方法合成的聚吡咯皆对基体有一定的防护作用,恒电流合成的涂层与CV法合成的涂层分别使钛基体的自腐蚀电位正移了96.11mV和60.42mV,相应地腐蚀电流密度降低了一个数量级。在整个浸泡过程中发现恒电流合成的涂层始终保持较高的开路电位,CV合成的涂层开路电位有下降趋势,最后与钛基体电位接近,综合表明恒电流合成的涂层相对CV合成的涂层抗腐蚀性能更好,涂层更加致密。
The polypyrrole(PPy)films were electrodeposited on the surface of pure titanium by using cyclic voltammetry and galvanostatic methods,respectively.The analysis techniques including SEM and FTIR were applied to characterize structures and morphology of the polymer coatings.The corrosion performance of the films in weak acid environments was investigated by means of potentiodynamic polarization,open-circuit potential versus time curves and electrochemical impedance spectroscopy techniques and so on.The results showed that the coatings obtained by these two synthesis techniques both offered certain protective properties for titanium matrix,the free corrosion potentials of the substrate was shifted to positive values by 96.11 mV for Galvanostatic method and approximately by 60.42 mV for the CV methods,respectively,at the same time,the corresponding corrosion current density was decreased approximately by an order of magnitude.During the whole immersion,the open potential of coatings got by galvanostatic always kept in high values,conversely,the open potential of CV coating tended to decline close to that of titanium substrate.It can be concluded that the coatings produced by galvanostatic have better corrosion resistance than that of CV method,and the films obtained by the galvanostatic method were denser than that of CV methods.