Theory of Organic Corrosion Inhibitors

The effect of aniline and aniline derivatives on the electrochemical characteristics of iron in has been studied using relaxation techniques. Armco iron corrosion was found to be inhibited primarily by an adsorption mechanism. However, evidence was noted which suggested a contribution from a "surface chelate." Evidence for surface chelation was more pronounced in the case of zone‐refined iron which showed a transition from a nearly "pure adsorption" to a predominant surface chelation process. Subsequent loss of inhibition with time by some organics has been attributed to charge transfer processes associated with the surface chelate.