How the Inhibition Performance Is Affected by Inhibitor Concentration: A Perspective from Microscopic Adsorption Behavior

Abstract

In this work, molecular dynamics simulations were employed to investigate the influence of inhibitor concentration on inhibition performance. The adsorption configuration, adsorption process, and inhibition performance were studied. We found that an ordered self-assembled inhibitor film can form on a metal surface, which plays a key role in corrosion inhibition. When the concentration reaches a critical value, inhibitor molecules organize into a micelle in aqueous solution. Further increasing the concentration did not change the inhibitor film on the metal surface, so that the inhibition efficiency remained at a constant level. Our analyses demonstrate that the number of water molecules displaced by inhibitor molecules, the diffusion of water molecules in the inhibitor film, and the stability of the inhibitor film play key roles in the process of corrosion inhibition. This work provides a thorough molecular-level understanding of inhibition behavior and the role of inhibitor concentration.

Electrochemical and anticorrosion properties of 5-hydroxytryptophan on mild steel in a simulated well-acidizing fluid

“…Olasunkanmi et al also obtained a similar trend and inferred mixed-type inhibitors with cathodic predominance because the magnitude of the net change was higher in β c than β a compared to the free acid solution [39]. In this study, larger changes in β a values were obtained than in β c values, supporting the hypothesis that the inhibitors show anodic predominance.…”

“…8 reveal that after immersion of the mild steel coupon, the band obtained in the UV-visible region shifted to lower absorbance values. This behaviour may be ascribed to a possible interaction between Fe 2+ and the inhibitor compounds in the inhibited solution [39]. This could have been due to some electronic transitions, such as n → π or n → π* (involving the non-bonding electrons of O and N) or π → π* (involving multiple bonds and a conjugated system), and the formation of a surface complex between the inhibitor and metal surface.…”

Effect of Aggregation and Adsorption Behavior on the Flow Resistance of Surfactant Fluid on Smooth and Rough Surfaces: A Many-Body Dissipative Particle Dynamics Study

“…Benefiting from the advantages of microscopic observation, molecular simulations have been utilized widely to study the aggregation and adsorption of surfactants at the solid/liquid interface as well as fluid in smooth/rough channels on the molecular level. ,− On the microscopic scale, different types of surfactants and different adsorbed amounts usually have various aggregated morphologies, ,,, resulting in different drag reduction effects. , Some research reported the influence of the boundary roughness on the friction of the fluid, but the intrinsic roughness of the surface was unchanged under the shear flow, which is different from a dynamic rough adsorption layer formed by surfactants . Therefore, it requires a systematic and molecular-level study to explore the influence mechanism of surfactant adsorption morphologies, fluid boundary roughness, and fluid viscosity on the flow resistance of wall-bound fluid.…”

Vesicle formation of catanionic mixtures of CTAC/SDS induced by ratio: a coarse-grained molecular dynamic simulation study

“…Molecular dynamic (MD) simulation, which can provide microscopic details, has been applied in extensive elds. [32][33][34][35] Mesoscopic molecular dynamics technologies, including coarse-grained molecular dynamics (CGMD) and dissipative particle dynamics (DPD) and so on, improve performance when handling larger lengths and timescales, and are powerfully exploited to investigate surfactant self-assembly in solutions. Wu et al 7 and Shillcock et al 8 applied CGMD and DPD, respectively, to studying the spontaneous vesicle self-assembly, and they both revealed the process of vesicle formation.…”