Equilibrium bundle size of rodlike polyelectrolytes with counterion-induced attractive interactions

作     者：Mark L. Henle Philip A. Pincus 

作者机构：Department of Physics University of California Santa Barbara California 93106 USA Department of Materials University of California Santa Barbara California 93106 USA Program in Biomolecular Science and Engineering University of California Santa Barbara California 93106 USA Department of Physics Korea Advanced Institute of Science and Technology Daejon 305-701 Republic of Korea 

出 版 物：《Physical Review E》 (物理学评论E辑：统计、非线性和软体物理学)

年 卷 期：2005年第71卷第6期

页      面：060801(R)-060801(R)页

核心收录：

学科分类：07[理学] 070203[理学-原子与分子物理] 0702[理学-物理学] 

主　　题：Phase equilibria 

摘      要：Multivalent counterions can induce an effective attraction between like-charged rodlike polyelectrolytes, leading to the formation of polelectrolyte bundles. In this paper, we calculate the equilibrium bundle size using a simple model in which the attraction between polyelectrolytes (assumed to be pairwise additive) is treated phenomenologically. If the counterions are pointlike, they almost completely neutralize the charge of the bundle, and the equilibrium bundle size diverges. When the counterions are large, however, steric and short-range electrostatic interactions prevent charge neutralization of the bundle, thus forcing the equilibrium bundle size to be finite. We also show that if the attractive interactions between the rods become frustrated as the bundle grows, finite-size bundles can be obtained with pointlike counterions.