Light-scattering studies of polymer solution dynamics

Abstract

Laser light scattering has been used to study the static and dynamic properties of polymers in solution. Interpretation of the intermediate scattering function S(K, t) from the center-of-mass diffusion to internal motions for both polymer coils and semiflexible chains is discussed. Crossover behavior of dynamic properties in dilute and semidilute solution regimes for polymers of finite molecular weight, instead of limiting scaling law exponents, is emphasized.

The complimentary nature of modern scattering techniques, as well as the use of specific probes, including anomalous scattering with synchrotron radiation, are likely to play an increasingly important role in investigating more complex interacting polymeric species, such as block copolymers, polyelectrolytes, and ionomers.

Measurements of time correlation function and methods of data analysis have been developed to determine the molecular weight distribution of synthetic polymers in dilute solution. In addition to center-of-mass diffusion studies in dilute solution from the good solvent region to the collapsed state, determinations of both cooperative and self-diffusion coefficients in semi-dilute solutions are within reach. Further quantitative analysis of S(K, t) awaits better theoretical models in the intermediate K range in semidilute solutions.