Table of Contents
Journal of Materials
Volume 2014, Article ID 101709, 11 pages
http://dx.doi.org/10.1155/2014/101709
Research Article

Acid Corrosion Inhibition and Adsorption Behaviour of Ethyl Hydroxyethyl Cellulose on Mild Steel Corrosion

1Department of Polymer and Textile Engineering, Federal University of Technology, P.M.B. 1526, Owerri, Nigeria
2Department of Polymer and Textile Engineering, Nnamdi Azikiwe University, P.M.B. 5025, Awka, Nigeria

Received 21 December 2013; Accepted 5 February 2014; Published 13 March 2014

Academic Editor: Jean-Francois Gohy

Copyright © 2014 I. O. Arukalam et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The corrosion inhibition of mild steel in 1.0 M H2SO4 solution by ethyl hydroxyethyl cellulose has been studied in relation to the concentration of the additive using weight loss measurement, EIS, polarization, and quantum chemical calculation techniques. The results indicate that EHEC inhibited corrosion reaction in the acid medium and inhibition efficiency increased with EHEC concentration. Further increase in inhibition efficiency is observed in the presence of iodide ions, due to synergistic effect. Impedance results reveal that EHEC is adsorbed on the corroding metal surface. Adsorption followed a modified Langmuir isotherm, with very high negative values of the free energy of adsorption . The polarization data indicate that the inhibitor was of mixed type, with predominant effect on the cathodic partial reaction. The frontier molecular orbitals, HOMO (the highest occupied molecular orbital) and LUMO (the lowest unoccupied molecular orbital) as well as local reactivity of the EHEC molecule, were analyzed theoretically using the density functional theory to explain the adsorption characteristics at a molecular level. The theoretical predictions showed good agreement with experimental results.