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The European Physical Journal BISSN: 1434-6028 (printed version) Abstract Volume 4 Issue 2 (1998) pp 205-217 Effects of ionic strength and charge annealing in star-branched polyelectrolytes
O.V. Borisov (1) (a), E.B. Zhulina (2) (a)
(1) University of Wageningen, Department of Physical and Colloid Chemistry, 6703 HB Wageningen, The Netherlands Received: 10 November 1997 / Revised: 16 February 1998 / Accepted: 1st April 1998 Abstract: We have developed a scaling theory that describes the conformations of weak star-branched polyelectrolytes in dilute solutions. The dependences of the overall star size on the number of branches and on the ionic strength of the solution (tuned by the addition of low molecular weight 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 swollen corona of the polyelectrolyte star consists of blobs which are not closely packed. We have shown that the size of star polyelectrolytes is less sensitive to the variation in the ionic strength than the size of linear polyelectrolytes. The effects of the ionization-recombination 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 strength of the solution due to recombination of counterions with charged monomers.
PACS. 36.20.Ey Conformation (statistics and dynamics) - 61.25.Hq Macromolecular and polymer solutions; polymer melts; swelling
(a) Permanent address: Institute of Macromolecular Compounds of the Russian Academy of Sciences, 199004, St. Petersburg, Russia Article in PDF-Format (371 KB) Online publication: August 10, 1998 |