Summary: Europhys. Lett., 61 (1), pp. 6773 (2003)
EUROPHYSICS LETTERS 1 January 2003
Polyelectrolyte persistence length: Attractive effect
of counterion correlations and fluctuations
G. Ariel and D. Andelman
School of Physics and Astronomy
Raymond and Beverly Sackler Faculty of Exact Sciences
Tel Aviv University - Tel Aviv 69978, Israel
(received 3 June 2002; accepted in final form 8 October 2002)
PACS. 61.25.Hq Macromolecular and polymer solutions; polymer melts; swelling.
PACS. 36.20.-r Macromolecules and polymer molecules.
Abstract. The persistence length of a single, strongly charged, stiff polyelectrolyte chain is
investigated theoretically. Path integral formulation is used to obtain the effective electrostatic
interaction between the monomers. We find significant deviations from the classical Odijk,
Skolnick and Fixman (OSF) result. An induced attraction between monomers is due to thermal
fluctuations and correlations between bound counterions. The electrostatic persistence length is
found to be smaller than the OSF value and indicates a possible mechanical instability (collapse)
for highly charged polyelectrolytes with multivalent counterions. In addition, we calculate the
amount of condensed counterions on a slightly bent polyelectrolyte. More counterions are found
to be adsorbed as compared to the Manning condensation on a cylinder.