Corrosion Inhibition of Cu-Zn-Fe Alloy in Hydrochloric Acid Medium by Crude Ethanol Extracts from Roots-Leaves Synergy of Solanum melongena

Abstract

The corrosion inhibition of Cu-Zn-Fe alloy in hydrochloric acid medium by crude ethanol extracts from roots-leaves synergy of Solanum melongena have been studied with chemical methods (mass loss and gasometric methods). At 3.0 grams per litre concentration of the roots-leaves synergy of Solanum melongena, it was observed that a 98.8 % inhibition efficiency was recorded as corrosion rate of alloy was decreasing with inhibitor increase. Temperature evaluation on the inhibitor showed 99.2 > 88.4 > 85.6 % as trial was conducted from 303-323 respectively, and in respect to increasing concentration, corrosion rate was found to be 1.718 > 0.013, 0.0192 and 0.247 at 303, 313 and 323 respectively. All these present a good result for the synergistic inhibitor and a proof of its efficiency in controlling the corrosion of Cu-Zn-Fe alloy in hydrochloric acid medium. Inhibition mechanism was deduced from the activation and thermodynamic parameters that govern the process. Adsorption of extract on the Cu-Zn-Fe alloy was found to obey the Langmuir adsorption isotherm. The phenomenon of physical adsorption is proposed from the obtained thermodynamic parameters.