Publications

In this paper we consider the influence of counterion distribution on the behavior of polyelectrolyte systems. We propose the unified model to describe and to compare the swelling and collapse properties of single polyelectrolyte chains in dilute solutions, microgel particles of various molecular masses, and las a limiting case) macroscopic gels. A novel feature of the new approach is that we distinguish three possible states of counterions: free counterions inside and outside the polymer macromolecule and a bound state of counterions forming ion pairs with corresponding ions of polymer chains. The latter possibility becomes progressively important when macromolecules or gels shrink. In this case the formation of a supercollapsed state is possible, when all counterions are trapped and form ion pairs. On the other hand, the fact that counterion scan float in the outer solution affects essentially the conformation of polyelectrolyte chains in dilute solutions of good quality where practically all counter ions can escape the spae inside polymer coils and the repulsion between uncompensated charges plays an important role in the chain behaviour.