Iron dissolution in aqueous AOT solution

The effects of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) on the electrochemical behavior of iron were studied by potentiodynamic and potentiostatic techniques and open-circuit potential measurements. Experiments were made in both neutral and alkaline AOT solutions (pH 7 and pH 12). It was found that AOT-assisted dissolution is initiated on a passivated iron surface and that the oxidation current leads to the formation of a gel-like film on the electrode surface. This dissolution process was investigated as a function of pH, potential, and electrode rotation rate and the corrosion products were characterized by polarizing microscopy, SEM/EDX, and IR spectroscopy. The gel-like material is a mixed NaAOT-Fe(AOT)(3) lamellar mesophase and a structure for this mesophase is proposed. (c) 2006 Elsevier Inc. All rights reserved.