Table of Contents
ISRN Materials Science
Volume 2012 (2012), Article ID 623754, 15 pages
http://dx.doi.org/10.5402/2012/623754
Research Article

Copper Corrosion Inhibition in 1โ€‰M HNO3 by Two Benzimidazole Derivatives

1Laboratoire de Chimie Physique, Universitรฉ de Cocody-Abidjan, BP 582 Abidjan 22, Cote D'Ivoire
2Laboratoire de Chimie Organique Structurale, Universitรฉ de Cocody-Abidjan, BP 582 Abidjan 22, Cote D'Ivoire

Received 25 November 2011; Accepted 5 January 2012

Academic Editors: F. Cabrera-Escribano and Y. Sun

Copyright © 2012 P. M. Niamien 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

Corrosion behavior of copper in 1โ€‰M nitric acid containing either 2-mercaptobenzimidazole (MBI) or 2-thiomethylbenzimidazole (TMBI) was investigated experimentally and theoretically via weight loss method and quantum chemical approaches. It was found that the two compounds exhibit a very good performance as inhibitors for copper corrosion in the studied medium. Results show that the inhibition efficiencies increase with increasing temperature and increasing concentration of the inhibitors. It has been found that the studied compounds adsorb onto copper according to the modified Langmuir adsorption isotherm and the kinetic/thermodynamic isotherm of El-Awady. The thermodynamic adsorption parameters and kinetic corrosion parameters were determined and analyzed; on the bases of these parameters both physisorption and chemisorption were suggested for the studied compounds. Furthermore, the quantum chemical properties/descriptors most relevant to their potential action as corrosion inhibitors have been calculated. They include ๐ธHOMO, ๐ธLUMO, energy gap (ฮ”๐ธ), dipole moment (๐œ‡), hardness (๐œ‚), softness (๐œŽ), the fractions of electrons transferred (ฮ”๐‘), electrophilicity index (ฯ‰), and the total energy change (ฮ”๐ธ๐‘‡). The theoretical results were found to be consistent with the experimental data reported.