Numerical Study of Critical Liquid Droplets Using Density Functional Theory for 2D Lattice Gas with Short-Range Interactions

The method of density functional theory (DFT) was used to create a simulation of a droplet inside a supersaturated vapor. This DFT model was based on a two-dimensional lattice structure with short-range interactions. Closest and second-closest neighbor interactions were included. An iterative numerical procedure was used to solve the DFT equation for the density profile of a critical liquid droplet. Droplets of different radii for a wide range of chemical potentials above coexistence were simulated. Surface tension was found to approach a maximum for a planar liquid-vapor interface as droplet radius increased at a constant temperature. Dependencies of surface tension on the radius shifted as temperature changed.