LIKE-CHARGE ATTRACTION IN POLYELECTROLYTE SOLUTIONS
The effective interactions between two test counterions and two test solvent dipoles in a semidilute/concentrated polyelectrolyte solution are studied using the field-theoretical approach on the mean-field level. From the effective Hamiltonians in terms of the two test counterions and the two test dipoles, respectively, analytical expressions for the effective interactions in the real space are derived. It is unambiguously demonstrated that, at a 9 solvent condition, both the effective interactions consist of an attractive part at intermediate distances of separation. As the electrostatic screening effect from the counterions and salt ions quantified by the Debye-Huckel screening parameter becomes stronger, the magnitude of the attraction decreases and the minimum of the attractive profile shifts to a shorter distance of separation (see Fig. 1). This nontrivial and seemingly counterintuitive result originates from the finite length of the monomer unit and the polymer chain configuration. This study offers an alternative view of the problem of like-charge attraction in polyelectrolyte solutions and shed new insight into the electrostatic screening effect of charges along the polyelectrolyte chains from a mean-field point of view.
Chaohui Tong
Department of Physics, Ningbo University, Ningbo, Zhejiang Province
国际会议
PP’2010，Jinan International Symposium on Polymer Physics(2010济南国际高分子物理学术研讨会)
济南
英文
192-193
2010-06-06（万方平台首次上网日期，不代表论文的发表时间）