Macroion attraction due to electrostatic correlation between screening counterions .1. Mobile surface-adsorbed ions and diffuse ion cloud
Macroion attraction due to electrostatic correlation between screening counterions .1. Mobile surface-adsorbed ions and diffuse ion cloud
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DOI：
10.1021/jp960458g
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发表时间：
1996-06-06
影响因子：
--
通讯作者：
Bloomfield, VA
中科院分区：
文献类型：
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作者：
Rouzina, I;Bloomfield, VA
在多价电解质溶液中，高电荷态的大离子表面通过反离子环境中的相互作用相互吸引。我们发现，当反离子分布具有伪二维特征时，会发生显著的关联。这使得我们可以通过将问题简化为具有相似电荷密度的被吸附但可移动的中和表面之间的相互作用来半解析地处理静电关联引力。无论是当反离子分布在二维极限时，还是当它具有更逼真的三维特性时，反离子之间的库仑斥力都会在表面产生正负电荷的交替。两个这样的相对图案相互补充地调整，导致表面的静电吸引。这种引力的大小仅取决于表面电荷密度和溶液的介电常数，而其范围则由每个离子周围平面相关孔的大小决定。相对于离子平面热运动的扰动影响，引力是稳定的。该理论使得构造一个普适函数成为可能，在用适当的系统参数标度后，该函数产生吸引人的静电关联压力。
Highly charged macroion surfaces in solutions of multivalent electrolytes attract each other electrostatically through correlations in their counterion environment. We show that significant correlation occurs when the counterion distribution has a pseudo-two-dimensional character. This allows us to treat the electrostatic correlation attraction semianalytically by reducing the problem to interaction between layers of adsorbed but mobile counterions neutralizing surfaces of similar charge density. Both when the counterion distribution is in the two-dimensional limit, and when it has a more realistic three-dimensional character, Coulomb repulsion between counterions produces an alternation of positive and negative charges at the surface. Two such apposing patterns adjust complementarily to each other, resulting in electrostatic attraction of the surfaces. The magnitude of this attraction depends solely on the surface charge density and the solution dielectric constant, while its range is defined by the size of the planar correlation hole around each ion. The attraction is stable with respect to the disruptive influence of planar thermal motion of the ions. The theory enables construction of a universal function which, after being scaled with the appropriate parameters of the system, yields the attractive electrostatic correlation pressure.