TITLE:
Synergistic Effect of Allium cepa-Zn2+ System on the Corrosion of Carbon Steel in Ground Water
AUTHORS:
A. John Amalraj, J. Wilson Sahayaraj, A. Peter Pascal Regis, Arockia Sahayaraj, P. Pandian, P. Johnraj, A. Kasthuri, C. Kumar
KEYWORDS:
Carbon Steel; Allium cepa; Corrosion Inhibition Efficiency; Ground Water
JOURNAL NAME:
Engineering,
Vol.5 No.2,
February
6,
2013
ABSTRACT: The corrosion inhibition efficiency (IE) of an aqueous extract Allium cepa (onion) in controlling the corrosion of carbon steel ground water in absence and presence of with Zn2+ has been studied by weight loss method. The formulation consisting of 3 mL Allium cepa extract, 50 ppm of Zn2+ and 50 ppm of sodium pattassium tartarate which offers 97% inhibition efficiency. The synergistic effect exists between onion-Zn2+-tartarate system. The addition of N-cetyl-N,N,N- trimethylammonium bromide on onion-Zn2+-tartarate system does not change the excellent inhibition efficiency. Polarization study shows that the onion-Zn2+-tartarate system functions as a cathodic inhibitor. AC impedance spectra reveals that a protective film is formed on the metal surface. The UV fluorescent spectra indicate the possibility of formation of Fe2+-onion complex and also Zn2+-onion complex in solution. Thus the protective film is found to be UV fluorescent.