Phase Separation Kinetics of Polyelectrolyte Solutions

University Of Massachusetts Amherst, Amherst MA

Investigators

Abstract

Thermodynamic stability of aqueous solutions of charged macromolecules is of central importance in all forms of life. Polyelectrolyte solutions in water exhibit complex behavior and present many intellectual challenges. We propose to perform experiments using light scattering and neutron scattering, and to carry out complementary theoretical calculations, pertinent to a fundamental understanding of the kinetics of phase separation in polyelectrolyte solutions. The specific experimental system of the proposed research is aqueous solutions of sodium polystyrene sulfonate containing known amounts of barium chloride. Our ongoing research on this subject points towards a breakthrough in our fundamental understanding of how charged macromolecules undergo phase separation. Clustering of similarly charged polymer chains is found to play an intermediary role during the primordial stages of the nucleation of the new stable phase, based on the limited preliminary data. The pro-posed research will establish the validity and general applicability of this newly discovered phenomenon. %%% The proposed research will have impact in medical research on disease control and a number of key industries including food, cosmetics, personal care products, and pharma-ceuticals. Furthermore, polyelectrolytes are emerging to be the most important, but least understood, materials. Training of graduate students in this important research area is the strong educational component of the proposed activity.