Experimental, Monte Carlo and molecular dynamics simulations to investigate corrosion inhibition of mild steel in hydrochloric acid solutions

Abstract

The efficiency of three furan derivatives, namely 2-(p-toluidinylmethyl)-5-methyl furan (Inh. A), 2-(p-toluidinylmethyl)-5-nitro furan (Inh. B) and 2-(p-toluidinylmethyl)-5-bromo furan (Inh. C), as possible corrosion inhibitors for mild steel in 1.0 M HCl, has been determined by weight loss and electrochemical measurements. These compounds inhibit corrosion even at very low concentrations, and 2-(p-toluidinylmethyl)-5-methyl furan (Inh. A) is the best inhibitor. Polarization curves indicate that all compounds are mixed-type inhibitors, affecting both cathodic and anodic corrosion currents. Adsorption of furan derivatives on the mild steel surface follows the Langmuir adsorption isotherm, and the calculated Gibbs free energy values confirm the chemical nature of the adsorption. Monte Carlo simulations technique incorporating molecular mechanics and molecular dynamics can be used to simulate the adsorption of furan derivatives on mild steel surface in 1.0 M HCl.

Experimental and computational evaluation of illicium verum as a novel eco‐friendly corrosion inhibitor for aluminium

“…While the deformation energy is, the energy released when the adsorbed adsorbate components are relaxed on the substrate surface. The adsorption energy is the sum of the rigid adsorption energy and the deformation energy for the adsorbate components . The results reveal that the molecules in the Types I and II categories show the highest adsorption energy for PMPP and OA.…”

Chitosan Schiff base as eco-friendly inhibitor for mild steel corrosion in 1 M HCl

“…[42] In general, if the ∆G ads values are around -20 kJ mol −1 or lesser related to physical nature of adsorption occurring through the electrostatic interaction between the charged molecules and charged metal while the ∆G ads values around -40 kJ mol −1 or higher related to chemical nature of adsorption that takes place due to the charge sharing or the charge transfer from the inhibitor molecules to the metal surface by forming coordinate bond. [43] log K ads = −log CH 2 O − ΔG ads RT ln K ads = ΔH ads RT + ΔS ads R The results presented in the Table 5 indicate that ∆G ads values are greater than −40 kJ mol −1 attributes to the strong chemical adsorption of the chitosan Schiff base on to the metal surface.…”

Corrosion inhibition for low-carbon steel in 1 M H2SO4 solution by phenytoin: evaluation of the inhibition potency of another “anticorrosive drug”

“…However, it is certainly not possible to accept these assumptions for a typical acid inhibition system such as that under study, since there could be influences of foreign ions and interactions in the same solution; some adsorption processes could also be potential dependent and selective regarding the types of charges on the metal surface. According to Khaled and El-Maghraby [25], to explain these discrepancies as they relate to adsorption phenomena, it is important to consider another physical characteristic of the adsorption isotherm. The Langmuir adsorption isotherm can be redescribed mathematically in terms of the dimensionless separation constant (K L ) shown in Eq.…”