Inhibition of CTAB on the Corrosion of Mild Steel in Hydrochloric Acid

Abstract

The inhibition effect of cetyl trimethyl ammonium bromide (CTAB) on the corrosion of mild steel in 1.0 mol L⁻¹ hydrochloric acid (HCl) has been studied at different temperatures (25–60°C) by weight loss and potentiodynamic polarization methods. The results reveal that CTAB behaves as an effective inhibitor in 1.0 mol L⁻¹ HCl, and the inhibition efficiency increases with the inhibitor concentration. Polarization curves show that CTAB is a mixed-type inhibitor in hydrochloric acid. The results obtained from weight loss and polarizations are in good agreement. The effect of immersion time on corrosion inhibition has also been examined and is discussed. The adsorption of inhibitor on mild steel surface obeys the Langmuir adsorption isotherm equation. Thermodynamic parameters have been obtained by adsorption theory. The inhibition effect is satisfactorily explained by the parameters.

Keywords:

• Corrosion inhibition
• CTAB
• potentiodynamic polarization
• surfactant
• weight loss

Acknowledgments

The authors gratefully acknowledged the support of National Key Technology R&D Program (Grant No. 2007BAB27B02, 2007BAB27B01) and Natural Science Foundation of Shandong Province (Grant No. ZR2009EQ008).