2020 Impact factor 1.890
Soft Matter and Biological Physics


Eur. Phys. J. E 8, 3-14 (2002)
DOI: 10.1140/epje/i2002-10007-3

The electrostatic persistence length of polymers beyond the OSF limit

R. Everaers1, A. Milchev1, 2 and V. Yamakov1, 2

1  Max-Planck-Institut für Polymerforschung, Postfach 3148, D-55021 Mainz, Germany
2  Institute for Physical Chemistry, Bulgarian Academy of Sciences, G. Bonchev Street, Block 11, 1113 Sofia, Bulgaria

everaers@mpip-mainz.mpg.de

(Received 12 February 2002)

Abstract
We use large-scale Monte Carlo simulations to test scaling theories for the electrostatic persistence length $l_\ab{e}$ of isolated, uniformly charged polymers with Debye-Hückel intrachain interactions in the limit where the screening length $\kappa^{-1}$ exceeds the intrinsic persistence length of the chains. Our simulations cover a significantly larger part of the parameter space than previous studies. We observe no significant deviations from the prediction $l_\ab{e}\propto\kappa^{-2}$ by Khokhlov and Khachaturian which is based on applying the Odijk-Skolnick-Fixman theories of electrostatic bending rigidity and electrostatically excluded volume to the stretched de Gennes-Pincus-Velasco-Brochard polyelectrolyte blob chain. A linear or sublinear dependence of the persistence length on the screening length can be ruled out. We show that previous results pointing into this direction are due to a combination of excluded-volume and finite chain length effects. The paper emphasizes the role of scaling arguments in the development of useful representations for experimental and simulation data.

PACS
64.60.-i - General studies of phase transitions.
36.20.-r - Macromolecules and polymer molecules.
87.15.By - Structure and bonding.


© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2002