VELOCITY-FIELD IN NONDRAINING POLYMER-CHAINS

The molecular-weight dependence of the intrinsic viscosity and the dif fusion coefficient of polymers in dilute solutions can be obtained by assuming the polymer chains to be rigid spheres of radius equal to the ir radius of gyration. This observation has been interpreted as implyi ng that the solvent within a polymer coil is dragged along with the co il, and that the coil with the occluded solvent acts like a hydrodynam ic entity. In order to question this very common interpretation, we ca lculate the velocity field in nondraining polymer chains. Our explicit results are at odds with the simple picture of nondraining polymer co ils acting like rigid spheres.