Modification of the electrochemical behavior of copper by azole compounds

Abstract

Cyclic voltammetry and chrnonocoulometry have been employed to study the anodic oxidation of copper in acetate-buffered media, and the effect of pretreatment of the copper surface by immersion in azole solutions on the anodic reactions was obeserved. Azole compounds have been shown to react with metallic copper to form surface films which in some cases provide protection against corrosion. The effects of benzotriazole, (BTA), imidazole (IMIDA) and benzimidazole (BIMIDA), all of which have been considered or used for the inhibition of undesirable surface reactions on copper, have been compared. Pretreatment of copper by immersion in azole solutions results in the inhibition of the anodic oxidation reactions of copper. More pronounced effects are obeserved for in situ studies, in which experiments are carried out as the copper electrode sits in the azole solution of interest. The degree on inhibition of anodic oxidation reactions produced by azole pretreatment decreases in order BTA > BIMIDA ≅ IMIDA. Investigations carried out at different pH values and different inhibitor concentrations may be useful in determining the optimum conditions for copper surface treatments. Electrochemical techniques may be used as a basis for comparing treated and untreated copper surfaces.