Kłos J, Pakula T
Faculty of Physics, A Mickiewicz University, Umultowska 85, 61-614 Poznań, Poland.
J Phys Condens Matter. 2005 Sep 21;17(37):5635-5645. doi: 10.1088/0953-8984/17/37/002.
Diluted solutions of a single, electrically charged polymer chain, its monovalent counterions and two kinds of multivalent salts are investigated. In particular, the influence of the salt concentrations and valences on the mean effective charge per monomer, total inner energy, radius of gyration and various pair correlation functions of the monomers and free ions are analysed. The calculations show that it is the four-valent and three-valent ions, oppositely charged to the monomers, that mostly occupy the space around the polymer and tremendously increase their number there compared to that in the bulk. Furthermore, reductions in the polymer size and effective charge per monomer appear, especially for increasing amount of the four-valent salt. Thus, there is an evidence for polymer conformational changes associated with the ion condensation onto the chain.
研究了单一的带电聚合物链、其单价抗衡离子以及两种多价盐的稀释溶液。特别地，分析了盐浓度和价态对每个单体的平均有效电荷、总内能、回转半径以及单体和自由离子的各种对关联函数的影响。计算结果表明，与单体带相反电荷的四价和三价离子主要占据聚合物周围的空间，并且与本体相比，极大地增加了聚合物周围这些离子的数量。此外，聚合物尺寸减小以及每个单体的有效电荷降低，特别是对于四价盐含量增加的情况。因此，有证据表明聚合物构象变化与离子在链上的凝聚有关。
