Imidazoline Gemini Surfactants as Corrosion Inhibitors for Carbon Steel X70 in NaCl Solution.

The Gemini imidazoline surfactants were synthesized from a series of saturated fatty acids. Electrochemical impedance spectroscopy (EIS), polarization curve, and quantum chemistry methods were used to study the corrosion inhibition behavior of Gemini imidazoline surfactants for X70 carbon steel in NaCl solution. Results reveal that such kind of surfactants has an outstanding inhibition effect on carbon steel X70 in NaCl solution and that the restrained efficiency of Gemini imidazoline in an alkaline solution is better than that in a neutral solution. The shorter the carbon chain length, the higher the suppressive efficiency. The higher the concentration of Gemini imidazoline surfactant, the better the inhibition effect.