INHIBITORY EFFICACY OF CAPPARIS DECIDUA EXTRACT ON THE CORROSION OF ALUMINIUM IN VARIOUS ACIDIC MEDIA

Abstract

The inhibition efficacy of ethanolic extract of various parts of Capparis decidua in acidic medium has been determined mploying gravimetric analysis at various concentrations. Values of inhibition efficiency achieved from the two techniques are in good agreement and are dependent upon the concentration of inhibitor and acid. The inhibition procedure is attributed to the creation of an amphoteric oxide film of inhibition on the Aluminium metal surface which protects the aluminium metal against corrosion. The adsorption of extract of Capparis deciduas on the aluminium surface was found to obey the Langmuir adsorption isotherm. The standard free energy (ΔG°ads) shows that extract from Capparis decidua undergoes physical adsorption on the surface of aluminium metal is spontaneous.