Solvent effects on mutual diffusion in concentrated polystyrene solutions

In a previous paper, mutual diffusion coefficients for concentrated solutions of a monodisperse polystyrene in 14 solvents were reported. In this paper, these data are reinterpreted in terms of new thermodynamic data for these solvents. These new results permit evaluation of the activity derivative, ∂ In a1/∂ In v1, and therefore enable calculation of the diffusional friction coefficient from the mutual diffusion coefficient. The friction coefficient was found to be directly proportional to solvent viscosity to within the experimental errors involved in the combined transport and thermodynamic measurements. The molecular implications of this result are discussed.