Shijie Wang  ,  Yufeng Zhang  ,  Yi Yang ,  Jing Xu ,  Hang Yin

Abstract 

The movement of ions and water molecules through C-S-H gel nanopores determines the overall properties of cementitious material. This paper focuses on investigating the effects of electric field orientation, solution concentration and surface structural heterogeneity on ionic and water transport behavior using Molecular Dynamics simulation method. Results show that a parallel electric field markedly accelerates Cl− migration and reduces its adsorption stability at the substrate surface. In contrast, the driving force in the perpendicular direction weakens due to spatial confinement. Water migration is mainly controlled by ion-water coupling interactions. Solution concentration further regulates transport and adsorption: at low concentrations, the weakening effect on the electric field is limited, and diffusion modes are all transport modes, while at high concentrations, stronger ion correlations and saturated adsorption sites diminish field-driven transport and lower adsorption efficiency. In addition, variations in surface structural heterogeneity among different C-S-H models cause significant differences in Cl− adsorption and diffusion, emphasizing the importance of analyzing multiple model replicas to obtain reliable simulation outcomes. All these findings reveal the important roles played by electric field orientation, solution concentration and surface structural heterogeneity during ionic and water transport inside C-S-H gel nanoparticles.

Paper Linkage:https://doi.org/10.1016/j.jobe.2026.116069