Article

Synergistic inhibition between the gemini surfactant and bromide ion for steel corrosion in sulphuric acid

Journal of Applied Electrochemistry (Impact Factor: 2.15). 01/2009; 39(6):779-784. DOI: 10.1007/s10800-008-9720-2

ABSTRACT The inhibitive synergistic effect between a cationic gemini surfactant, 1,3-propane-bis(dimethyl dodecylammonium bromide)
(12-3-12), and bromide ion for the corrosion inhibition of cold rolled steel in 0.5molL−1 H2SO4 was investigated by weight loss, potentiodynamic polarization method and electrochemical impedance spectroscopy (EIS). The
inhibition system composed by 12-3-12 and bromide ion is efficient. The adsorption mechanism of the 12-3-12 and bromide ion
on steel in acidic medium is discussed on the basis of experimental data and an adsorption model is proposed. Adsorption of
inhibitor system on the mild steel surface in acidic medium obeys Langmuir’s adsorption isotherm. In addition, potentiodynamic
polarization studies show that the system acts as a mixed-type inhibitor. Electrochemical impedance spectroscopy also suggests
the formation of a protective layer on the steel surface by the adsorption of surfactant molecules and bromide ions.

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