Adsorption and Inhibitive Properties of Ethanol Extracts of Leaves of Solanum Melongena for the Corrosion of Mild Steel in 0.1 M HCl

作者：Eddy Nnabuk O^*; Awe Femi; Ebenso Eno E

来源：International Journal of Electrochemical Science, 2010, 5(12): 1996-2011.

• Mild steel
• corrosion
• inhibition
• adsorption
• Solanum melongena

Inhibitive and adsorption properties of ethanol extracts of leaves of Solanum melongena (SM) were studied using gravimetric, gasometric, thermometric and FTIR methods. The results obtained indicated that the ethanol extract of leaves of SM is a good adsorption inhibitor for the corrosion of mild steel in HCl solution. The inhibition efficiency of ethanol extracts of leaves of SM was found to increase with increasing temperature. The adsorption of the ethanol extracts of leaves of SM on mild steel surface is exothermic, spontaneous and is best described by the Langmuir adsorption model. The values of activation and free energies obtained were within the range limits expected for the mechanism of physical adsorption. Quantum chemical calculations revealed that the active constituents of ethanol extracts of leaves of SM are carotene, nicotinic acid, ascorbic acid and riboflavin and that the order for their inhibition potentials is thiamine >beta-carotene > riboflavin > ascorbic acid > nicotinic acid. Examination of the FTIR spectra of the corrosion products of mild steel and that of ethanol extracts of leaves of SM before and after adsorption indicated that the adsorption of the inhibitor is enhanced by the aromatic and C = C in beta-carotene and -OH bonds in thiamine, riboflavin, ascorbic acid and nicotinic acid.

• 出版日期2010-12
• 单位西北大学