Synergistic Inhibition Effect of Imidazoline and Thiourea: Evidence from Experiments and Molecular Dynamics Simulation

Abstract

Mass loss method, electrochemical tests, SEM morphology analysis, and molecular dynamics simulation were employed to study the synergistic mechanism of imidazoline (IM) and thiourea (TU) on ASTM A106B steel in CO2-saturated NaCl solution. The experimental results clearly revealed that imidazoline and thiourea had good synergistic corrosion inhibition effect, and the combination of 5mg/L IM and 5mg/L TU exhibited the highest inhibition efficiency of 95.1%. Inhibitors molecules replaced the water molecules originally adsorbed on the metal surface and played inhibition effects. The adsorption of the inhibitor mixtures had better inhibition effect than individual inhibitors. The adsorption configuration and inhibition performance of the inhibitors demonstrated that the TU molecules first adsorbed on the metal surface to form the first layer, and then the IM adsorbed on TU to form the second layer. The number of water molecules originally adsorbed on the Fe surface decreased, and the diffusion of water molecules in the inhibitor film slowed down, thereby playing a synergistic inhibition effect on metal corrosion.

Design and fabrication of a stable Ni-PTFE-SiC superhydrophobic anticorrosive coating by electrodeposition

“…CPE dl and CPE c are constant phase angle elements to simulate the capacitance at the interface of solution/ substrate and solution/coating 45 . Considering the roughness and energy dissipation of the electrode surface 32 , the constant phase angle element is often used to replace the ideal capacitance, and its impedance is defined by Eq. ( 5):…”

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