Titrating Polyelectrolytes - Variational Calculations and Monte Carlo Simulations
Abstract
Variational methods are used to calculate structural and thermodynamical properties of a titrating polyelectrolyte in a discrete representation. The Coulomb interactions are emulated by harmonic repulsive forces, the force constants being used as variational parameters to minimize the free energy. For the titrating charges, a mean field approach is used. The accuracy is tested against Monte Carlo data for up to 1000 monomers. For an unscreened chain, excellent agreement is obtained for the end-to-end distance and the apparent dissociation constant. With screening, the thermodynamical properties are invariably well described, although the structural agreement deteriorates. A very simple rigid-rod approximation is also considered, giving surprisingly good results for certain properties.
Keywords
Cite
@article{arxiv.chem-ph/9506004,
title = {Titrating Polyelectrolytes - Variational Calculations and Monte Carlo Simulations},
author = {B. Jönsson and M. Ullner and C. Peterson and O. Sommelius and B. Söderberg},
journal= {arXiv preprint arXiv:chem-ph/9506004},
year = {2008}
}
Comments
22 pages, PostScript, 9 figures