Kinetics of phase change in binary mixtures with complete wetting interfaces

Some properties are described of the nucleation and the spinodal decomposition of a binary mixture in the neighbourhood of a three-phase coexistence state that exhibits complete wetting of one phase at the interface of the other two. A square-gradient density functional approach to inhomogeneities in only one spatial direction is applied, and an analysis is attempted with the help of the equivalent nonlinear dynamic system. The different possible types of behaviour are visualized in terms of orbits in the corresponding phase portraits. There are some exceptional structural, prewetting and wetting film, features both for critical nucleation droplets and for spatially periodic stationary states of spinodal decomposition.