Overlap Concentration in Salt-Free Polyelectrolyte Solutions

TitleOverlap Concentration in Salt-Free Polyelectrolyte Solutions
Publication TypeJournal Article
Year of Publication2021
AuthorsJA Bollinger, GS Grest, MJ Stevens, and M Rubinstein
JournalMacromolecules
Volume54
Start Page10068
Issue21
Pagination10068 - 10073
Date Published11/2021
Abstract

For strongly charged polyelectrolytes in salt-free solutions, we use molecular dynamics simulations of a coarse-grained bead-spring model to calculate overlap concentrations c∗ and chain structure for polymers containing N = 10 to 1600 monomers. Over much of this range, we find that the end-to-end distance R∗ at c∗ increases faster than linearly with increasing N, as chains at the overlap concentration approach strongly extended conformations. This trend results in the overlap concentration c∗ decreasing as a stronger function of N than the classical prediction c∗ ∼N-2. This stronger dependence can be fit either by a logarithmic correction to scaling or by an apparent scaling c∗ ∼N-m, with m > 2.

DOI10.1021/acs.macromol.1c01491
Short TitleMacromolecules