Structure of nonuniform polymer melts: density functional perturbation approach

A density functional perturbation approximation for polyatomic molecules, which is based on the fundamental-measure theory for hard-core repulsion and the hybrid weighted-density approximation for chain connectivity, was proposed to clarify the structure of polymer melts at interfaces. It was applied to predict the local density distributions, adsorption isotherms, and surface excess of a freely jointed tangent hard-sphere chain in hard slit pores. Wertheim's first-order perturbation theory extended by J. Chem. Phys. 112, 2368 (2002)] was used to calculate the weight function and second-order direct correlation function due to the chain connectivity. The theoretical results are in excellent agreement with the computer simulations.