Nucleation and Growth of Droplets in Vapor-Liquid Transitions

Results for the kinetics of vapor-liquid transitions, following temperature quenches with different densities, are presented from the molecular dynamics simulations of a Lennard-Jones system. For critical density, bicontinuous liquid and vapor domains are observed which grow with time obeying the prediction of hydrodynamic mechanism. On the other hand, for quenches with density significantly below the critical one, phase separation progresses via nucleation and growth of liquid droplets. In the latter case, Brownian diffusion and collision mechanism for the droplet growth is confirmed. We also discuss the possibility of inter-droplet interaction leading to a different amplitude in the growth law. Arguments for faster growth, observed at early time, are also provided.