Inhibition of acid corrosion of aluminum using vanillin

The inhibition efficiency (IE) of vanillin towards the corrosion of aluminum in 5 M HCl solution was measured using weight loss measurement, hydrogen evolution method, thermometry and potentiostatic polarization techniques. The results drawn from the different techniques are comparable and exhibit a small discrepancy. It was found that vanillin acts as a good inhibitor for the corrosion of aluminum in 5 M HCl solution. The IL increases as the concentration of vanillin is increased. The inhibition action of vanillin is discussed in view of the adsorption of its molecules on the electrode surface through the active centers contained in its structure. It was found also that adsorption of vanillin on aluminum surface follows Langmiur adsorption isotherm. (C) 2001 Elsevier Science Ltd. All rights reserved.