Gas-liquid nucleation in partially miscible systems: Free-energy surfaces and structures of nuclei from density functional calculations

Gas-liquid nucleation in partially miscible Lennard-Jones systems is studie d using the density functional theory in a perturbation approach. Nucleatio n properties are examined in a symmetric and an asymmetric mixture. Both sy stems are shown to form two kinds of mixed critical nuclei in one vapor com position. Spherically symmetric clusters with a phase separated structure a re found in the asymmetric mixture; these are shown to correspond to local maxima of the Gibbs free-energy surface. A classical calculation also sugge sts that the cylindrically symmetric clusters found in earlier studies have higher formation energies than the spherical nuclei in the same vapor. (C) 1999 American Institute of Physics. [S0021-9606(99)51936-3].