Freezing Effects on the Behavior of Diffused Double Layer Using Molecular Dynamics: Fid-Bau Portal

Freezing Effects on the Behavior of Diffused Double Layer Using Molecular Dynamics

Wei, Shijun / Abdelaziz, Sherif L.

This study evaluates the behavior of diffused double layer (DDL) around cohesive clay particles under freezing temperatures using molecular dynamics. A better understanding of the physical molecular interactions related to the diffused double layer behavior between frozen soil and water is the key contributions of this study. The electrolyte system for this model is built by implementing the kaolinite system suggested by Bish combined with SPC/E water system in LAMMPS (large-scale atomic/molecular massively parallel simulator). Interactions between water and basal surfaces of kaolinite clay particles are studied due to its larger surface area compared to the clay edges. Simulations are proceeded under different temperatures ranging from 173 K (about –100°C) to 373 K (about 100°C) to capture the thermodynamics and diffused double layer behavior for the combined electrolyte system consisting of frozen soils and water. Quantitative analysis like radial distribution function is applied at the different temperatures to capture the variations in the behavior of diffused double layer. The results show a different pattern of thermodynamic properties but very similar radial distribution function analysis, which yields a minimal different behavior of diffused double layer for clay-water electrolyte system under freezing temperatures.