Molecular Scale Aspects of Liquid Contact on a Solid Surface

Abstract

Molecular dynamics simulations related to the contact structure of liquid droplet on a solid surface are compared for a simple Lennard-Jones fluid system and a practical water-on-platinum system. The contact angle for the Lennard-Jones system seems to be simply scaled with the potential energy parameter between liquid and solid, even though the layered liquid structure near the surface gives some complexity. On the other hand, a water droplet in contact with a platinum surface shows quite intrigue results. The water droplet gives a finite contact angle on the absorbed monolayer water film. The contact angle is determined by the surface energy between this monolayer water film and bulk liquid water. The dependence of contact angle on the platinum crystal lattice structure is explained by the structure of this monolayer water film.