EFFECTS OF IONIC-STRENGTH AND CHARGE ANNEALING IN STAR-BRANCHED POLYELECTROLYTES

We have developed a scaling theory that describes the conformations of weak star-branched polyelectrolytes in dilute solutions. The dependen ces of the overall star size on the number of branches and on the ioni c strength of the solution (tuned by the addition of low molecular wei ght salt) are analyzed. The intrinsic structure of the polyelectrolyte stars in salt-free and salt-added solutions is discussed in terms of concentration and elastic blobs. In contrast to neutral stars, the swo llen corona of the polyelectrolyte star consists of blobs which are no t closely packed. Mie have shown that the size of star polyelectrolyte s is less sensitive to the variation in the ionic strength than the si ze of linear polyelectrolytes. The effects of the ionization-recombina tion balance in the star polyelectrolyte were taken into account. For polyelectrolytes with small ionization constant; the size of the star depends nonmonotonically on the number of branches and on the ionic st rength of the solution due to recombination of counterions with charge d monomers.