A Molecular Dynamics Simulation of a Bubble Nucleation on Solid Surface

A heterogeneous nucleation of a vapor bubble on a solid surface was simulated by the molecular dynamics method. Liquid argon between parallel solid surfaces was gradually expanded, until a vapor bubble was nucleated. Argon liquid was represented by 5488 Lennard-Jones molecules and each surface was represented by three layers of harmonic molecules with the constant temperature heat bath model. With a visualization of void patterns, the density fluctuations leading to the nucleation were compared for different wettability of the surface. The wettability was varied by changing the potential between argon and solid molecule. The over-all shape of the vapor bubble or the "contact angle" was measured at the equilibrium condition achieved after the expansion.