Retropective and developing concepts of passivity and passivity breakdown of metallic materials in organic solutions

Various studies have offered to explain the passivity of metals in organic solvents and the effect of water on passivation processes. This has often assumed that organic solvents are inert to metals and alloys. Some explanations have related passivity to solvent adsorption characteristics. Others have suggested that corrosion of metals in organic solvents depended primarily on solution conductivity and acidity. The specific type, structure, and reactions possible for an organic functional group influence the reactivity of metals and alloys in organic solvents. Organic solvents transport the reactants and products involved in passivity or corrosion processes at the metal surface. The genus of solvents in use and their solvation properties will determine the solubility of these reactants or products. Many different physical and chemical interactive forces occur during solvation. These interactive forces play a significant role in determining the mechanistic paths that, in turn, can affect the passivity of different alloys in a given organic solvent or in mixtures of two or more organic solvents with or without water. In addition, the character of the passive oxide films oil metals and alloys will influence the possible mechanistic paths and the potential regions where passivity is effective for these materials.