IFF-2, Institut für Festkoperforschung, Forschungszentrum Jülich, D-52425 Jülich, Germany.
J Phys Chem B. 2010 Apr 29;114(16):5241-9. doi: 10.1021/jp910960r.
In the first part of the paper, we study the collapse of flexible highly charged polyelectrolyte chains induced by attractive dipole-dipole interactions. The latter emerge due to the formation of dipoles between the chain monomers and counterions condensed on the polyelectrolyte from solution. Using the statistics of slightly perturbed Gaussian polymers, we obtain the scaling relations for the chain dimensions as a function of polyelectrolyte linear charge density in the limit of compacting chains. The results are in good agreement with the outcomes of recent molecular dynamics simulations of the collapse of flexible polyelectrolytes in the presence of explicit counterions. In the second part, we analyze the results of molecular dynamics simulations for the complex formation by two highly charged polyelectrolyte chains carrying opposite charges. We use the scaling arguments based on the picture of complexation of electrostatic blobs in order to rationalize the size of the complexes of two polyelectrolyte chains in the collapsed state. Similar scaling relation for the complex size was recently obtained in computer simulations of complexation of diblock polyampholytes and was described theoretically on the basis of similar electrostatic blob concepts. We also analyze the density of complexes formed and polyelectrolyte linear charge densities required for the onset onto the collapse as a function of interaction strength between the monomers. In both parts of the paper, we overview the scaling relationships obtained for similar systems with alternating charges from other theoretical approaches.
在本文的第一部分，我们研究了由于链单体之间以及从溶液中凝聚在聚电解质上的抗衡离子之间形成偶极子而引起的吸引力偶极子相互作用导致的柔性高电荷聚合物链的坍塌。利用略微扰动的高斯聚合物统计，我们获得了在紧凑链极限下聚电解质线电荷密度作为链尺寸函数的标度关系。这些结果与最近在存在显式抗衡离子的情况下柔性聚合物链坍塌的分子动力学模拟的结果非常吻合。在第二部分，我们分析了带有相反电荷的两条高电荷聚合物链形成复合物的分子动力学模拟结果。我们使用基于静电斑点复合的标度论点来合理化在坍塌状态下两条聚合物链复合物的大小。最近在双嵌段聚两性电解质的络合计算机模拟中得到了类似的复合物大小的标度关系，并基于类似的静电斑点概念从理论上进行了描述。我们还分析了形成复合物的密度和作为坍塌起始所需的聚电解质线电荷密度作为单体之间相互作用强度的函数。在本文的两部分中，我们从其他理论方法概述了类似的具有交替电荷的系统所获得的标度关系。
