Corrosion Inhibition Effect of Cationic Surfactant on Steel in Acid Medium and Synergistic Effect of Chloride Ion and Some Alcohols

Corrosion inhibition effect of cationic surfactant DTAB (dodecyl three methyl ammonium bromide) on low carbon steel in 1M HCl was studied using weight loss method. Inhibition efficiency increased with the increase of surfactant concentration. The adsorption of the surfactant on the steel surface forms a barrier layer on the surface and it was the main reason of its inhibition effect. Effect of three long chain alcohols C7OH (1-heptanol), C12OH (1-dodecanol), C15OH (1-pentanol) on inhibition efficiency of DTAB was studied considering chain length compatibility. Also synergistic effect between surfactant and chloride ions in 1M HCl was investigated with the presence of different concentration of NaCl. The inhibition efficiency increased with the increase of NaCl concentration and reached the maximum value near 0.1 M. This composite inhibitor system containing cationic surfactant and chloride ions was efficient and low-cast for steel corrosion inhibition in HCl medium. J. Color Sci. Tech. 2(2009), 257-263.© Institute for Colorants, Paint and Coatings.