Nucleation in molecular and dipolar fluids: Interaction site model

Abstract

We consider the effect of molecular anisotropy and dipole moment on the rate of homogeneous and heterogeneous nucleation of molecular and dipolar fluids. Density functional theory is applied to an interaction site model of molecules composed of two tangent or fused hard spheres interacting through Lennard-Jones and coulombic potentials. Interfacial properties are conditioned by entropy vs energy competition. For nucleation on a charged hard sphere, the calculated rates depend strongly on the size and charge of the central seed. Preferred surface orientations of the dipolar molecules are responsible for nucleation rates differing by several orders of magnitude for charges of different sign.