A Monte Carlo study of solutions of oppositely charged polyelectrolytes
A Monte Carlo study of solutions of oppositely charged polyelectrolytes
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DOI：
10.1063/1.1460859
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发表时间：
2002-04-15
影响因子：
4.4
通讯作者：
Linse, P
中科院分区：
文献类型：
--
作者：
Hayashi, Y;Ullner, M;Linse, P
采用两种不同的模型，用蒙特卡罗模拟方法研究了含相反电荷聚电解质溶液中络合物的形成。这些多离子被描述为由20个相连的带电硬球组成的柔性链，浸泡在代表水的均匀电介质背景中。小离子或者被显式地包括在内，或者它们的影响通过使用屏蔽库仑势来描述。模拟溶液包含10个带正电荷的聚离子和0、2或5个带负电荷的聚离子以及各自的反离子。考虑了两种不同的线电荷密度，确定了结构因子、径向分布函数和多离子扩展。随着带负电荷的多离子数目的增加，正电多离子重新分布，其中包括相反带电的多离子之间形成的强络合物。发现络合物的性质取决于链的线电荷密度。包含屏蔽库仑势的简化模型与具有显式小离子的模型给出了定性相似的结果。最后，由于复杂形体的形成，在构型空间中的抽样是非平凡的，并检验了不同试步的效率。(C)2002年美国物理研究所。
The formation of complexes appearing in solutions containing oppositely charged polyelectrolytes has been investigated by Monte Carlo simulations using two different models. The polyions are described as flexible chains of 20 connected charged hard spheres immersed in a homogenous dielectric background representing water. The small ions are either explicitly included or their effect described by using a screened Coulomb potential. The simulated solutions contained 10 positively charged polyions with 0, 2, or 5 negatively charged polyions and the respective counterions. Two different linear charge densities were considered, and structure factors, radial distribution functions, and polyion extensions were determined. A redistribution of positively charged polyions involving strong complexes formed between the oppositely charged polyions appeared as the number of negatively charged polyions was increased. The nature of the complexes was found to depend on the linear charge density of the chains. The simplified model involving the screened Coulomb potential gave qualitatively similar results as the model with explicit small ions. Finally, owing to the complex formation, the sampling in configurational space is nontrivial, and the efficiency of different trial moves was examined. (C) 2002 American Institute of Physics.