Molecular dynamics analysis on the contribution of van der Waals and Coulomb interactions to the solid-liquid work of adhesion

摘要

Molecular dynamics simulations of film systems containing a water-silica interface were performed to investigate the effect of van der Walls and Coulomb interactions on solid-liquid work of adhesion. Thermodynamic integration based dry-surface method was employed to calculate the solid-liquid work of adhesion of various systems where solid-liquid interactions were changed by both modifying van der Walls and Coulomb interactions. A simple linear relation was shown between solid-liquid energy and work of adhesion indicating that change in interfacial entropy was proportional to that of interfacial energy. The precise interfacial energy/entropy ratio depended on the nature of solid-liquid interaction, which allowed creation of systems with identical solid-liquid interfacial energies, but different energies of adhesion, i.e. different wettabilities. Finally, a way to interpret solid-liquid interfacial entropy as proportional to variance of solid-liquid energy was offered, providing a way to qualitatively estimate solid-liquid interface energetic properties.