Molecular dynamics simulations of spinodal decomposition in films of binary mixtures

A molecular dynamics investigation of spinodal decomposition in films of a binary mixture demonstrates that the phenomenon "Surface-directed spinodal decomposition," first obtained experimentally by Jones et al. [Phys. Rev. L ett. 66, 1336 (1991)], is caused not by a decomposition directed from the s urface and driven by a preferential attraction toward the surface of one of the components but by the symmetry break. The main effect of this symmetry break is a decomposition into a laminar sandwich structure of separated fl uid phases for film of a thickness bigger than a certain critical thickness . The domain growth exponent in the vertical direction is, and the growth i n horizontal is approximate to 1/2, which corresponds to two-dimensional vi scous growth.