Molecular Dynamics Study of Adsorption and Wetting of Mixtures of Simple Fluids on Planar Walls

The influence of molecular interactions on the adsorption and wetting of binary mixtures was studied by molecular dynamics simulations of sessile droplets on planar walls. The results provide insights into the competing effects between the fluid-fluid interactions and the solid-fluid interactions on the adsorption and wetting of mixtures. All interactions were modeled by the Lennard-Jones truncated-shifted (LJTS) potential. The influence of the different dispersive interactions in the fluid mixture as well as those between the fluid components and the wall on the gas and liquid adsorption, the three-phase contact, and the contact angle was determined. For the fluid mixtures studied in the present work, the phase behavior and the vapor-liquid interfacial properties are known from recent studies. Together with the present results, this provides a comprehensive picture of the influence of different molecular interactions on the closely related phenomena of wetting and adsorption in mixtures.