Corrosion Inhibition of Carbon Steel by Imidazolium and Pyridinium Cations Ionic Liquids in Acidic Environment

New imidazolium-based ionic liquids and some pyridinium-based ionic liquids, were tested as corrosion inhibitors of steel in 1.0 M HCl using potentiodynamic polarization, linear polarization and weight loss methods. The obtained results showed that all of the four ILs are good inhibitors for steel in 1.0 M HCl and the inhibition efficiency increased with increasing the inhibitor concentration. All of the ILs act as mixed-type inhibitors. Obtained results from Tafel polarization, linear polarization and weight loss are in good agreement with each other. The adsorption of the four ILs inhibitors, obey the Langmuir adsorption isotherm. From the adsorption isotherm, values of ΔGads for the adsorption process were calculated. The effect of temperature on the corrosion behavior of steel in presence of 1 × 10-3 M of compound II was studied in the temperature range 298-338 K.