On modelling surface directed spinodal decomposition

Cahn-Hilliard theory for symmetric binary polymer mixtures is used to study the influence of a surface which is attractive to one component of the polymer blend. We revisit modelling approaches to the dynamics of a polymer blend at or near a surface to show that quantitative agreement with previous models is only possible if a number of issues are resolved. We address the issue of how the numerical length scales chosen during the simulation affect the accuracy of the magnitude of surface segregation when a blend is undergoing spinodal decomposition. Finally we investigate whether equilibration has any effect on the morphology of the blend at the surface or in the bulk after a quench into the two-phase region has occurred.