Corrosion Inhibition Properties of Chitosan Doped With Fe, Cu, Zn, and Co on the Fe(110) Surface: A Combined DFT and Monte Carlo Simulation Study

Abstract
Because corrosion causes major environmental and economic damage, long-term corrosion inhibitors are needed. Chitosan is not a single polymer with a particular structure; rather, it is a mixture of molecules with different sizes, contents, and distributions of monomers. The novelty of the current project to examine is the first study to predict potential corrosion inhibition properties of chitosan doped with Fe, Cu, Zn, and Co with names: CS, CS-Fe, CS-Zn, CS-Cu, and CS-Co using the DFT/B3LYP/6-311++G(d,p) basis set in both gas and aqueous phases. In addition, Monte Carlo (MC) simulations were used to reveal the adsorption of the studied compounds on the Fe(110) surface. Comparing the MC simulation results for adsorption on Al(111) metallic surfaces to the previous DFT analysis revealed the small energy HOMO–LUMO gap (0.582 eV), chemical hardness (0.291 eV), larger electron transfer (6.209), and softness 3.432 eV−1 observed in the DFT analysis. The MC simulation more negative suggest stronger adsorption, with the strongest adsorption energy (−293,300 kcal/mol) found for CS–Zn inhibitor compounds in the gas phase, which means that it chelates more strongly than other metals in the form of strong bonds on Al(111) surfaces. To put it simply, a high adsorption energy enables the inhibitor to cling securely to the surface and form an effective protective layer that either prevents or delays possible corrosion.

Author
Rebaz Anwar Omer

DOI
https://doi.org/10.1002/sia.70026

ISSN
1096-9918

Publish Date: 27-Sep-2025