The dielectric spectrum of flexible polyelectrolyte solutionsC.-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
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.
77.22.Gm - Dielectric loss and relaxation.
66.10.-x - Diffusion and ionic conduction in liquids.
82.35.Rs - Polyelectrolytes.
© Europhysics Letters Association 2007