Inhibition effect of 4,4′-thio bis{N-[(E)-phenol-3-ylmethylidene]aniline} on the corrosion of mild steel in HCl solution under stagnant condition and hydrodynamic flow

The inhibition effect of a new Schiff base, namely, 4,4 '-thio bis{N-[E-phenol-3-ylmethylidene]aniline}(SB), on the corrosion of mild steel (MS) in a 1M HCl solution was investigated under both hydrodynamic flow and a stagnant environment at different temperatures and concentrations. To assess the inhibition effect, different characterization techniques have been used including the measurement of weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). It was found that the inhibition efficiency increases with the increase of the inhibitor concentration and decreases when the temperature increases. The adsorption of the inhibitor on the surface of MS obeys the Langmuir isotherm. The surfaces of MS, after being exposed to test solutions, were examined by atomic force microscopy (AFM).