Synergistic Inhibition Effect of Dimeric Surfactant 12-2-12 and Halide Ions on the Corrosion of A3 Carbon Steel in 1M HCl Solution

The inhibitive synergistic effect between a cationic dimeric surfactant, 1,2-ethane-bis(dimethyl dodecylammonium bromide) (designed as 12-2-12), and halide ions (X-) for the corrosion inhibition of A3 carbon steel in 1 M HCl solution was investigated by polarization curve and weight loss methods. The inhibition system composed by 12-2-12 and X- is efficient. The percentage inhibition efficiency (eta%) for each inhibition system increased with increasing KX concentration. The optimum dosage is around 0.1 similar to 1mM of halide salts in the presence of 12-2-12. And the inhibition efficiency (eta) increased according to the order: 12-2-12/I- >12-2-12/Br- >12-2-12/Cl-. The maximum inhibition efficiency of 12-2-12/I- approached 99.3% when KI concentration reached a limiting value at 0.1mM.