Dynamic light scattering measurements of the relaxation times of internal modes of single polymer chains in semidilute solution are reported for dilute high molecular weight polystyrene in a semidilute poly(vinylmethylether)/toluene host. Since PVME is index matched by toluene, these light scattering measurements probe the dynamics of the isolated polystyrene chains and are insensitive to the collective fluctuations of the PVME host. The principle result is that the Rayleigh linewidth scales like the third power of the momentum transfer regardless of the concentations of the semidilute polymer. This is in apparent contradiction to current theories of hydrodynamic screening in semidilute solutions, which predict a fourth power dependence for the linewidth.

This content is only available via PDF.
You do not currently have access to this content.