Distribution of segments near the surface of a melt of linear flexible macromolecules: Effect on surface tension

Abstract The concept of configuration swap introduced previously (A. Silberberg, J. Colloid Interface Sci. 90, 86 (1982)) gives a method for constructing the conformations of a flexible polymer chain in the melt near a surface. This has now been used to compute the distribution of centers of mass and the distribution of segments around them in the surface zone. The constraints imposed by the surface correspond to a reduction in entropy and a positive contribution to the temperature coefficient of surface tension. This effect provides a small upward shift and can be used to bring the prediction for the surface tension, by C. I. Poser and I. C. Sanchez (based on a gradient of density through the surface zone optimized by the Cahn-Hilliard approach, J. Colloid Interface Sci. 69, 539 (1979)), into full agreement with experiment.