Reversible (physical) gelation in the solutions of associating polyelectrolytes

The gel and sol formation in dilute solution of polyelectrolyte telechelics are studied and a role of the charged groups and counter ions in the association process is determined. The chains can aggregate and form either finite size clusters or physical gel depending on polymer concentration in the system if the attraction between the stickers is strong enough. The optimum size clusters are the most stable at small enough values of polymer concentrations. The formation of clusters with optimum size in polyelectrolyte systems is similar to the classical problem of the instability of a charged droplet. The equilibrium state of the system is a set of smaller droplets of certain size with the charge on each of them lower than the critical value.