Corrosion Inhibition of Aluminium Alloy in 0.75 M KOH Alkaline Solution Using Xylopia aethiopica Seed Extract
O. F. Nwosu *
Physics/Electronics Department, Abia State Polytechnic, Aba, Nigeria and Physics Department, University of Port Harcourt, Choba, Nigeria
E. Osarolube
Physics Department, University of Port Harcourt, Choba, Nigeria
*Author to whom correspondence should be addressed.
Abstract
The present study investigated the corrosion inhibition of Al alloy in 0.75 M KOH solution at room temperature using X. aethiopica seed extract. Gravimetric technique was employed in the study. It was revealed that the presence of the spice extract in the test solution retards the corrosion rate. The calculated inhibition efficiency from the inhibitor surface coverage was observed to increase linearly with the inhibitor concentration. The consideration of the Langmuir adsorption isotherm indicated that the mechanism of adsorption is Physisorption. Temkin isotherm models explained that there were lateral attractions of the inhibitor molecules on the Al alloy surface. Flory-Huggins isotherm model confirms that there is bulky displacement of water molecules on the metal surface due to the presence of the inhibitor molecules.
Keywords: Corrosion inhibition, Xylopia aethiopica, adsorption isotherm