Inhibiting effects of 2-mercapto-1-methylimidazole on copper corrosion in 0.5 M sulfuric acid

The inhibiting efficiency of 2-mercapto-1-methylimidazole (MMI) on copper corrosion in sulfuric acid was investigated at 30 degrees C. Its effectiveness was assessed through electrochemical impedance spectroscopy, potentiodynamic polarization and gravimetric measurements. The results of study reveal that the inhibition efficiency of MMI depends on its concentration and attains approximately 81% at 10(-4) M. The inhibitor was adsorbed on the copper surface according the Langmuir adsorption isotherm model. The value of standard free energy of adsorption was calculated from this isotherm. (C) 2010 King Saud University. All rights reserved.