The goal in recent studies of the action of inhibitors has been to apply some of the concepts and experimental techniques that have been fruitful in problems of electrode kinetics, heterogeneous catalysis and, to some extent, semiconductor physics. The purpose has been to determine fundamentally the manner in which an inhibitor of corrosion acts.
In order to disclose the nature of the corrosion process to be inhibited, some of the recent work on the anodic process is discussed. The importance of adsorption and of semiconducting surfaces in the kinetics of electrode reactions is illustrated.
The principal theories of inhibitor action are outlined and discussed in the light of recent experimental studies, in which radioactive tracers have had a prominent role.
In considering the physical-chemical basis for the specificity of solute species as inhibitors, it is shown that such species may interact with a solid phase through a variety of mechanisms. These include oxidation-reduction processes, adsorption and ion-exchange, and electrostatic polarization. The effects of these interactions are shown to correlate with phenomena observed in the adsorption of gases on metals and in certain surface properties of semiconductors. The conclusion reached is that a comprehensive consideration of all such types of interaction is necessary for an understanding of the action of inhibitors.
5.8.3, 5.8.4, 3.2.2
