Spreading of Liquid Mixtures at the Microscopic Scale: A Molecular Dynamics Study of the Surface-Induced Segregation Process

The spreading of liquid mixtures on a solid substrate is studied using Molecular Dynamics. The droplets are constituted by 16-atom and 8-atom chains and the solid substrate is described at the atomic level. In all the simulations reported here, the atoms are, for simplicity, equidistributed among the two types of molecules (50%−50%). The influence of the strength of the solid, short molecules interaction on the coating of the solid surface by the liquid first layer is analyzed, for both the “wetting/nonwetting” and “wetting/wetting” mixtures. A surface-induced segregation process of the mixture is reported in the “wetting/nonwetting” case and the conditions according to which this segregation of the initial drop occurs are investigated.