Corrosion Inhibition of Mild Steel by Extract of Bryophyllum Pinnatum Leaves in Acidic Solution

Abstract

Bryophyllum pinnatum leaves extract has been evaluated as mild steel corrosion inhibitor in 0.5 M HCl solution by gravimetric analysis and Scanning electron microscope techniques. Effect of temperature and inhibitor concentrations on the corrosion behaviour of mild steel were studied and found that inhibition efficiency increases as inhibitor concentration increases but decreases as the temperature increases. The activation energy and thermodynamic parameters were studied, results direct that corrosion process involve the exothermic process and adsorption of inhibitor molecules follows the physical adsorption on metal surface. Linearity of Langmuir adsorption isotherm shows the formation of monolayer over the metal surface by deposition of inhibitor molecules. SEM analysis reveal the smooth surface which indicate the protective adsorption of inhibitors molecules on metal surface. The results reveal that the extract of bryophyllum pinnatum act as an effective corrosion inhibitor for the mild steel corrosion in 0.5 M HCl medium.

Keywords: Adsorption, Corrosion, SEM, Weight loss