%0 Journal Article
%T Naturally Occurring Elettaria cardamomum Extract as a Corrosion Inhibitor for the Dissolution of Zinc in 1.0£¿M HCl
%A M. Sobhi
%J ISRN Corrosion
%D 2012
%R 10.5402/2012/971650
%X The inhibitive action of water extract of naturally occurring Elettaria cardamomum plant against the corrosion of zinc in 1.0£¿M HCl solution was investigated using weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy. From these measurements, it was found that the values of surface coverage (¦È) and inhibition efficiency increase with increasing the concentration of the extracted compound. The activation energy of the corrosion was calculated and it was found that the presence of the extracted compound in 1.0£¿M HCl solutions increases the values of activation energy. The inhibiting effect of this extract results from its adsorption on the electrode surface via the adsorption centers of the compounds present in the extract. The adsorption of this extract compound onto the surface of zinc follows the Langmuir adsorption isotherm. The thermodynamic parameters were calculated for the tested system from the data obtained at different temperatures. 1. Introduction Corrosion of zinc has been a subject of numerous studies due to its high technological value and wide range of industrial applications and economic importance; its protection against corrosion has attracted much attention. The use of inhibitors is one of the most practical methods for protection against corrosion especially in acidic media [1]. Most of the well-known corrosion inhibitors are organic compounds containing nitrogen, sulphur, and oxygen atoms [2¨C7]. This study sets out to develop a safe method of corrosion protection, harmless to nature but still effective against corrosion, by searching for natural products. The purpose of this study wants to discover new, environmentally friendly corrosion inhibitors, that is, material protection compounds, based on components from naturally occurring. Recently, plant extracts have again become important as an environmentally acceptable, readily available, and renewable source for a wide range of needed inhibitors. Plant extracts are viewed as an incredibly rich source of naturally synthesized chemical compounds that can be extracted by simple procedures with low cost [8]. Elettaria cardamomum Maton is an important member of the family Zingiberaceae. The seeds contain essential oil in concentration of about 4% of dry weight. The main compound is 1,8-cineole (representing 50% or more), with smaller amounts of ¦Á-terpineol and limonene [9, 10]. The present work aims to study the effect of dry fruits extracts of E. cardamomum as a corrosion inhibitor for the corrosion of zinc in 1.0£¿M£¿HCl. Moreover, the effect of
%U http://www.hindawi.com/journals/isrn.corrosion/2012/971650/