Nonlinear counterion screening in colloidal suspensions
Nonlinear counterion screening in colloidal suspensions
复制标题
胶体悬浮液中的非线性抗衡离子筛选
DOI：
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发表时间：
1993
期刊：
影响因子：
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通讯作者：
P. Madden
中科院分区：
文献类型：
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作者：
H. Löwen;J. Hansen;P. Madden
提出了一种新的“从头算”方法，该方法旨在模拟高度不对称的带电粒子系统，如胶束溶液和电荷稳定的胶体悬浮液。混合描述认为宏观离子的自由度明确，而微观抗衡离子的密度泛函理论的框架内处理。反离子密度分布被视为一个动力学变量，这是耦合到macroion的位置;相应的运动方程推导出拉格朗日包含一个虚构的动能项与非均匀的反离子密度，与虚构的质量选择，使反离子尽可能接近表面的最低自由能（绝热条件）。采用经典赝势方法，在不破坏宏观离子表面外的反离子密度分布的快速变化的情况下，抑制了宏观离子表面反离子密度分布的不连续行为。
A new ‘‘ab initio’’ method is presented which is designed to simulate highly asymmetric systems of charged particles such as micellar solutions and charge‐stabilized colloidal suspensions. The hybrid description considers the macroion degrees of freedom explicitly, while the microscopic counterions are treated within the framework of density functional theory. The counterion density profile is treated as a dynamical variable which is coupled to the macroion positions; the corresponding equation of motions are derived from a Lagrangian which contains a fictitious kinetic energy term associated with the inhomogeneous counterion density, with a fictitious mass chosen so that the counterions stay as close as possible to the surface of lowest free energy (adiabatic condition). The discontinuous behavior of the counterion density profile at the macroion surfaces is suppressed by the use of a classical pseudopotential scheme without spoiling the rapid variation of the counterion density profile outside the macro...