Issue
EPL
Volume 80, Number 6, December 2007
Article Number 67002
Number of page(s) 5
Section Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
DOI http://dx.doi.org/10.1209/0295-5075/80/67002
Published online 05 November 2007
EPL, 80 (2007) 67002
DOI: 10.1209/0295-5075/80/67002

The dielectric spectrum of flexible polyelectrolyte solutions

C.-Y. D. Lu

Department of Chemistry, National Taiwan University - Taipei 106, Taiwan and Department of Physics, and Center of Theoretical Physics, National Taiwan University - Taipei 106, Taiwan


received 25 September 2007; accepted in final form 15 October 2007; published December 2007
published online 5 November 2007

Abstract
The simplest version of the double-layer polarization theory for the flexible polyelectrolyte solution is formulated where the thin-double-layer limit is taken. The double-layer region of the polyelectrolyte contains the excess fluxes of charge and salt where the off-diagonal Onsager coefficient couples the charge- and the neutral-salt dynamics. The dynamic charge and the salt distributions are solved for the weakly charged polyelectrolyte. We calculate the free-energy storage and loss under the applied AC electric field to obtain the dielectric function, which depends on the chain configuration through the chain structure factor. A simple mean-field structure factor for the flexible chains is used to calculate the dielectric spectrum for the full range of the polyelectrolyte concentration.

PACS
77.22.Gm - Dielectric loss and relaxation.
66.10.-x - Diffusion and ionic conduction in liquids.
82.35.Rs - Polyelectrolytes.

© Europhysics Letters Association 2007