Physics – Condensed Matter – Soft Condensed Matter
Scientific paper
2004-06-02
European Physical Journal E (2004) vol. 14, issue 1, pages 67-77
Physics
Condensed Matter
Soft Condensed Matter
11 pages, 6 figures
Scientific paper
10.1140/epje/i2004-10007-3
We reconsider the electrostatic contribution to the persistence length, $\ell_e$, of a single, infinitely long charged polymer in the presence of screening. A Gaussian variational method is employed, taking $\ell_e$ as the only variational parameter. For weakly charged and flexible chains, crumpling occurs at small length scales because conformational fluctuations overcome electrostatic repulsion. The electrostatic persistence length depends on the square of the screening length, $\ell_e\sim\kappa^{-2}$, as first argued by Khokhlov and Khachaturian by applying the Odijk-Skolnick-Fixman (OSF) theory to a string of crumpled blobs. We compare our approach to previous theoretical works (including variational formulations) and show that the result $\ell_e\sim\kappa^{-1}$ found by several authors comes from the improper use of a cutoff at small length scales. For highly charged and stiff chains, crumpling does not occur; here we recover the OSF result and validate the perturbative calculation for slightly bent rods.
Manghi Manoel
Netz Roland R.
No associations
LandOfFree
Variational theory for a single polyelectrolyte chain revisited 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 Variational theory for a single polyelectrolyte chain revisited, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Variational theory for a single polyelectrolyte chain revisited will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-348510