Adsorption Mechanism of 4-(4,5-diphenyl-1H-imidazole)-N,N-dimethylbenzenamine as a Corrosion Inhibitor Towards Carbon Steel in 1% NaCl Solution

Corrosion inhibitor is one of the materials widely known to effectively minimize damages caused by corrosion. Design and development of corrosion inhibitor have been intensively studied. Understanding the mechanisms responsible in corrosion inhibition is demanded in developing techniques to prevent corrosion. This study employed an imidazole derivate compound, 4-(4,5-diphenyl-1H-imidazole)-N,N-dimethylbenzenamine, as a corrosion inhibitor on carbon steel in a corrosive environment of 1% NaCl at 25 oC. Analysis of the mechanisms underlying the adsorption of the organic inhibitor on metal surface was performed by electrochemical impedance spectroscopy method. The adsorption mechanisms were analyzed by Langmuir and Temkin adsorption isotherm models. The fitting results showed that the linear regression obtained from Langmuir and Temkin adsorption isotherm were 0.9738 and 0.8694, respectively. The adsorption free energy was -34.04 kJ/mol, indicated that Langmuir adsorption isotherm was applied in the adsorption mechanism and that the inhibitor was adsorbed semi-physically or semi-chemically on the metal surface