Corrosion Inhibition and Adsorption Characteristics of Jatropha curcas Leaves Extract on Aluminium in 1M HCl

摘要

Corrosion inhibition of aluminium (AA 1060) in 1M HCl by Jatropha curcas leave extracts was studied using weight loss method at 30℃, 40℃, 50℃ and 60℃. The results obtained indicate that the extracts inhibited the corrosion process in the medium by adsorption and that corrosion rate increased with rise in temperature. Corrosion rate was also found to decrease in the presence of the inhibitor as compared to the blank. Inhibition efficiency was found to increase with increased inhibitor concentration but reduces with increase in temperature to a maximum of 76.49% at 30℃ and 0.5g/L concentration of the leave extract. The change in Gibbs free energy of adsorption was -16.99kJ/mol at 30℃ and decrease with increase in temperature to -13.54kJ/mol at 60℃. The adsorption of the plant extract on aluminium surface was found to obey Temkin, Freundlich and El-Awady adsorption isotherms. Physical adsorption mechanism is proposed for the adsorption of the leaves extract on the aluminium surface.