Comparative Study of the Corrosion Inhibition and Adsorption of Ripe and Unripe Plantain (Musa paradisiaca) Peel Extract on Zinc in 2.0M CH3COOH Acid Solution

Abstract

This aim if this study was to investigate the corrosion inhibition and adsorption of both ripe and unripe Musa paradisiaca peel on zinc sheet in 2.0M CH₃COOH acid solution. The corrosion inhibition study was carried out using weight loss study at temperatures of  303K, 313K and 323K. Comparatively the peel extract of the ripe Musa paradisiaca showed higher inhibition efficiency to corrosion than the unripe with tannins as the main difference in the constituents which has higher concentration of tannin in the ripe and very minute in the unripe. The inhibition efficiency of the both extracts was found to decrease with rise in temperature. The experimental data complied to the Henry, Flory-Huggins and Adejo-Ekwenchi isotherms amongst which the Henry Isotherm gave the best fit having the highest regression (R²) values for both the ripe and unripe. The positive values of ∆H_ads and negative values ∆G_ads revealed the endothermic nature and spontaneity of the adsorption process respectively. Through the Kinetic-thermodynamic parameters such as E_a,, ∆H_ads,, ∆S_ads, ∆G_ads and the b parameter of the Adejo-Ekwenchi isotherm, the mechanism of adsorption was physisorption.