ON THE POSSIBLE ROLE OF NONELECTROSTATIC INTERACTIONS IN THE MECHANISM OF THE SLOW POLYELECTROLYTE MODE OBSERVED BY DYNAMIC LIGHT-SCATTERING

The effect of a poor solvation of a polyelectrolyte chain backbone in a polar solvent was investigated as a possible origin of large multichain domains in polyelectrolyte solutions giving rise to the slow polyelectrolyte mode observed by dynamic light scattering. It was investigated if these domains could be interpreted as polymeric aggregates formed due to the poor backbone solvation. Static and dynamic light scattering experiments on polyions in solvents of different quality with respect to the polyelectrolyte chain backbone, and the temperature dependence of the slow mode, showed that this hypothesis is not realistic. Poor solvation of the polyelectrolyte chain backbone in polar solvents is therefore not the origin of domain formation in solutions of strongly charged polyelectrolytes. This conclusion was confirmed also by analysis of literature data in view of the investigated issue. © 1994 American Institute of Physics.