A study of the diffusion of compact particles in polymer solutions using quasi-elastic light scattering

This paper describes an investigation, using quasi-elastic light scattering, of the diffusion of polystyrene spheres through solutions of dextran. The diffusion coefficient, D, of the spheres is shown to vary inversely with the volume fraction, phi, of dextran according to D = D0/(1 + vphi + kphi2). Changes in the molecular weight of dextran are shown to reflect changes in the macromolecular shape parameter, v, and the interaction parameter, k. This result differs from previous studies which suggested an exp( Bphi1/2) dependence and no molecular weight dependence [8].