The fraction of condensed counterions around a charged rod: Comparison of Poisson-Boltzmann theory and computer simulations

Details The fraction of condensed counterions around a charged rod: Comparison of Poisson-Boltzmann theory and computer simulations The fraction of condensed counterions around a charged rod: Comparison of Poisson-Boltzmann theory and computer simulations

1999-06-17

arxiv.org/abs/cond-mat/9906277v2

Macromolecules 33, 199 (2000)

Physics

Condensed Matter

Soft Condensed Matter

8 pages, 6 figures, using RevTeX style, revised version, 1 figure and more pertinent remarks concerning the failure of the ene

Scientific paper

10.1021/ma990897o

We investigate the phenomenon of counterion condensation in a solution of highly charged rigid polyelectrolytes within the cell model. A method is proposed which -- based on the charge distribution function -- identifies both the fraction of condensed ions and the radial extension of the condensed layer. Within salt-free Poisson-Boltzmann (PB) theory it reproduces the well known fraction 1-1/xi of condensed ions for a Manning parameter xi>1. Furthermore, it predicts a weak salt dependence of this fraction and a breakdown of the concept of counterion condensation in the high salt limit. We complement our theoretical investigations with molecular dynamics simulations of a cell-like model, which constantly yield a stronger condensation than predicted by PB theory. While the agreement between theory and simulation is excellent in the monovalent, weakly charged case, it deteriorates with increasing electrostatic interaction strength and, in particular, increasing valence. For instance, at a high concentration of divalent salt and large xi our computer simulations predict charge oscillations, which mean-field theory is unable to reproduce.

Affiliated with

Also associated with

No associations

Rating

The fraction of condensed counterions around a charged rod: Comparison of Poisson-Boltzmann theory and computer simulations does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The fraction of condensed counterions around a charged rod: Comparison of Poisson-Boltzmann theory and computer simulations, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The fraction of condensed counterions around a charged rod: Comparison of Poisson-Boltzmann theory and computer simulations will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-620116