%0 Journal Article
%T Inhibiting Effects of Rabeprazole Sulfide on the Corrosion of Mild Steel in Acidic Chloride Solution
%A M. K. Pavithra
%A T. V. Venkatesha
%A M. K. Punith Kumar
%J International Journal of Electrochemistry
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/714372
%X The corrosion inhibition effect of Rabeprazole sulfide (RS) on mild steel in 1£¿M hydrochloric acid (HCl) was investigated using weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and chronoamperometric measurements. Protection efficiency of RS increases with the concentration and decreases with the rise in temperature. Adsorption of RS on mild steel surface in 1£¿M HCl follows Langmuir adsorption isotherm. The kinetic and thermodynamic parameters governing the adsorption process were calculated and discussed. The polarization results suggest that RS performed as an excellent mixed-type inhibitor for mild steel corrosion in 1£¿M HCl. 1. Introduction Mild steel is widely used in many industries due to its excellent mechanical properties and low cost. However, it undergoes corrosion to a greater extent in acidic environment. Acids are employed in several industrial processes such as acid pickling, cleaning, acid descaling, and oil well acidizing. The use of HCl in these processes is more economical, efficient, and trouble-free, compared to other mineral acids [1]. In order to avoid the base metal attack, chemical inhibitors are often used for these processes to control the metal dissolution. The most well-known acid corrosion inhibitors are the heterocyclic compounds containing nitrogen, sulphur, and oxygen atoms [2¨C5]. Generally inhibitors act through the process of surface adsorption and its adsorption depends on the nature and surface charges on the metal, the type of aggressive media, the structure of inhibitor molecules, and its interaction with the metal surface [6]. Previously, large numbers of organic compounds have been investigated as corrosion inhibitors for mild steel in HCl media [7¨C11]. Even though these compounds show good anticorrosive action, they are toxic in nature. This led investigations to focus on the development of nontoxic corrosion inhibitors like drugs. A few investigations have been reported on the use of drugs such as cefazolin [1], Ampicillin [12], antifungal drugs [13], sulfa drugs [14], and rhodanine azosulpha drugs [15] as corrosion inhibitors. The inhibitory action of tramadol and tacrine on mild steel in 1£¿M HCl has been reported by Prabhu et al. [16] and Nataraja et al. [17]. Rabeprazole sulfide is the commercial name of (2-[[4-(3-Methoxypropoxy)-3-methylpyridine-2-yl]-methylthio]-1H-benzimidazole). It is a metabolite of an antiulcer drug, Rabeprazole. We have investigated the corrosion inhibition effect of this compound on mild steel in 0.5£¿M H2SO4 media in a previous article [18].
%U http://www.hindawi.com/journals/ijelc/2013/714372/