%0 Journal Article %T Surface Protection of Carbon Steel by Hexanesulphonic Acid-Zinc Ion System %A C. Mary Anbarasi %A Susai Rajendran %J ISRN Corrosion %D 2014 %R 10.1155/2014/628604 %X Inhibition of corrosion of carbon steel in dam water by hexanesulphonic acid as its sodium salt C6H13SO3Na (SHXS) in the absence and presence of a bivalent cation zinc ion (Zn2t) has been investigated using weight loss method. Results of weight loss method indicate that inhibition efficiency (IE) increased with increase of inhibitor concentration. Polarization study reveals that SHXS-Zn2+ system controls the cathodic reaction predominantly. AC impedance spectra reveal that a protective film is formed on the metal surface. The nature of the metal surface has been analysed by Fourier Transform Infrared Spectroscopy (FTIR) and Atomic Force Microscopy (AFM). 1. Introduction Corrosion is a naturally occurring phenomenon which deteriorates a metallic material or its properties because of a reaction with its environment. Corrosion can cause dangerous and expensive damage to everything from pipelines, bridges, and public buildings to vehicles, water, and wastewater systems, and even home appliances. It is one of the most serious problems in the oil and gas industry. The use of organic inhibitors is one of the most widely practical methods for protection of metals and alloys against corrosion. The efficiency of an organic compound as a corrosion inhibitor is closely associated with the chemical adsorption [1¨C4]. Most well-known organic inhibitors contain nitrogen, sulfur, and oxygen atoms due to their ability to form an adsorbed protective film at the metal/media interface. Studies report that the adsorption of organic inhibitors mainly depends on some physicochemical properties of the molecule, related to its functional groups, to the possible steric effects and electronic density of donor atoms: adsorption is supposed also to depend on the possible interaction of P-orbitals of the inhibitor with d-orbitals of the surface atoms, which induce greater adsorption of the inhibitor molecules onto the surface of carbon steel, leading to the formation of a corrosion protective film [5]. A survey of the available literature reveals that the corrosion inhibition of 2-naphthalenesulfonic acid, 2, 7-naphthalenedisulfonic acid, and 2-naphthol-3, 6-disulfonic acid on Armco-iron electrode in sulfuric acid has been investigated by Vra£żar and Dra£żi. The inhibition efficiency changes with the number of functional groups substituted on the benzene ring and increases with concentration [6]. The inhibition action of 2-mercaptobenzoxazol, 2-mercapto benzimidazole, N-cetyl pyridinium bromide, and propargyl benzene sulphonate on the corrosion of carbon steel in acid media has also %U http://www.hindawi.com/journals/isrn.corrosion/2014/628604/