Iron dissolution in aqueous AOT solution.

Area of Science:

• Electrochemistry
• Materials Science
• Corrosion Science

Background:

• Iron's electrochemical behavior is crucial in many industrial applications.
• Understanding surface interactions with surfactants like AOT is key to controlling corrosion.
• Passivation layers on iron can be altered by specific chemical agents.

Purpose of the Study:

• To investigate the electrochemical effects of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) on iron.
• To elucidate the mechanism of AOT-assisted iron dissolution.
• To characterize the corrosion products formed in the presence of AOT.

Main Methods:

• Potentiodynamic and potentiostatic polarization techniques.
• Open-circuit potential measurements.
• Electrochemical analysis coupled with microscopy (polarizing, SEM/EDX) and spectroscopy (IR).

Main Results:

• AOT initiates iron dissolution from a passivated surface.
• Oxidation current leads to the formation of a gel-like film.
• The film is identified as a mixed NaAOT-Fe(AOT)3 lamellar mesophase.

Conclusions:

• AOT plays a significant role in the electrochemical dissolution of iron.
• A proposed structure for the NaAOT-Fe(AOT)3 lamellar mesophase was determined.
• The findings provide insights into surfactant-induced corrosion mechanisms.