Synergistic Inhibition Mechanism of Imidazolidine and Sodium Lauryl Polyoxyethylene Ether Sulfate for Q235 Steel in H2so4 Solution: Combining Experimental Measurements with Theoretical Calculations

The synergistic inhibition mechanism of imidazolidine (IM) with sodium lauryl polyoxyethylene ether sulfate (SLPES) for the corrosion of Q235 steel in H2SO4 solution was systematically studied by experimental and theoretical methods. The results show that there is a synergism between IM and SLPES with a maximum inhibition efficiency of 94.5 %. IM/SLPES retards both anodic and cathodic reactions to more extent as compared with IM or SLPES. SEM, AFM, CLSM and XPS reveal that IM/SLPES can form a denser inhibition film on steel surface through the co-adsorptions of IM and SLPES, which can also well be elucidated by theoretical calculations.