Adsorption Mechanism of Cu2S on Insulating Paper Surface Based on Molecular Dynamics Simulation

The phenomenon of sulfur corrosion in transformers is attributed to the adsorption and deposition of copper sulfide (Cu₂S) on the surface of insulating paper and copper windings, leading to insulation deterioration. By analyzing the mechanism of copper sulfide adsorption on the surface of insulating paper, it can provide valuable insights into improving the sulfur corrosion resistance of insulating paper. In this paper, a copper sulfide-cellulose paper interface model is constructed based on molecular dynamics simulations to investigate the microscopic mechanism of copper sulfide adsorption on the surface of insulating paper. The results indicate that the interaction between copper sulfide and cellulose results in the rapid adsorption of copper sulfide on the interface of insulating paper. Further analysis, based on the radial distribution function and the hydrogen bonding theory, revealed that the sulfur atoms could form stable hydrogen bonds with the hydroxyl groups in the cellulose molecule. The shorter hydrogen bonds, near 1.5Å, are more numerous and exhibit larger bonding angles, whereas the longer hydrogen bonds, near 2.5Å, are fewer in number and have smaller bonding angles. Additionally, the temperature has little effect on the hydrogen bonds at the interface. The results of this study can provide a theoretical foundation for improving the sulfur corrosion resistance of insulating paper.