缓蚀剂阳极脱附现象的研究──Ⅰ．缓蚀剂阳极脱附现象

ANODIC DESORPTION OF INHIBITORS──Ⅰ.THE PHENOMENON OF ANODIC DESORPTION OF INHIBITORS

金属在缓蚀剂体系中的阳极极化曲线上存在着电流迅速增加而形成的电位平阶现象。逆向扫描极化时，这个电位平阶消失。这一现象起因于吸附在电极表面的缓蚀剂发生阳极脱附。文中提出用一电化学参数—脱附电位Ｅｄｅｓ来表征缓蚀剂阳极脱附现象。Ｅｄｅｓ是缓蚀剂大量脱附时的电位，其物理意义为缓蚀剂在电极表面因阳极极化而引起脱附速度稍大于其吸附速度。缓蚀剂阳极脱附速度取决于外加电位与脱附电位的差值。外加电位越正于脱附电位，缓蚀剂脱附速度越大；反之，缓蚀剂不发生阳极脱附。

he behaviour of inhibitor desorption from iron eledrode upon anodic polarization was investigated by polarization measurements. It was found that there was a potednd plateau characterized by a rapid current rise on anodic polarization curve in the presence of inhibitor and the potedial plateau disappeared during sequent reverse potential scanning. This phenomenon was probably caused by the inhibitor desorption from iron surface as it was anodically polarized. An eledrochemical parameter-desorption potential,Edes was defined to describe the performance of inhibitor desorption, corresponding to the potential at which the desorption rate is equal to the adsorption rate for the inhibitor. The inhibitor desorption rate was dependent on the difference between desorption potential and applied potential. The more positive than Edes the applied potential was, the faster the inhibitor desorption would be.AS the applied potential was more negative than Edes, no inhibitor desorption would occur.