Rescaled Free-Volume Theory of Diffusivity of Polystyrene in Various Organic Solvents.

It remains, as yet, far from satisfactory to account for the explicit role of the solvent effect on the transport behaviors of various polymer solutions, especially depending upon the polymer concentration. Here, we exploit the statistical mechanical free-volume theory to describe the diffusivity of polymer solutions in an analytical form in terms of the solvent-solvent, particle-particle, and solvent-particle pair correlation functions as a function of the polymer concentration. To be specific, we introduce a particle size scaling parameter as a measure of the effective polymer-solvent interaction that leads to different polymer globular states, depending on the embedding solvents.