Investigation of Corrosion Inhibition Potential of Ethanol Extract of Balanites aegyptiaca Leaves on Mild Steel in 1 M Hydrochloric Acid Solution.

Abstract

The corrosion inhibition effect of Balanites aegyptiaca leaves extract (BALE) on mild steel in 1 M hydrochloric acid solution has been investigated using gravimetric study and potentiodynamic polarization (PDP) measurements. The inhibition efficiency from weight loss studies was found to be 96.64% whereas 99.98% was obtained from potentiodynamic polarization studies at optimum concentration of 1.25 g/L of BALE. The PDP studies revealed that the BALE at different concentrations of the inhibitor acted as a mixed-type inhibitor. The inhibition efficiency is found to increase with increase in concentrations of the inhibitor and decrease with rise in temperature. The thermodynamic parameters and results from UV (i.e shift of bands from 227.84nm to 223.84nm and appearance of 203.94nm, 207.99nm and 325nm) and FTIR (shift from 1208cm -1 to 1205 cm -1 and 1618 cm -1 to 1611 cm -1 and appearance of new 1016 cm -1 , 1676 cm -1 , 1834 cm -1 , 3905 cm -1 bands etc) revealed the adsorption of the inhibitor molecules on mild steel surface as comprehensive adsorption (physical and chemical adsorption) and closely obey Langmuir adsorption isotherm. Surface analysis by UV, FTIR, XRD andSEM confirmed the formation of the adsorbed layer on the mild steel surface.