Nonlinear poisson-boltzmann theory of a wigner-seitz model for swollen clays
Nonlinear poisson-boltzmann theory of a wigner-seitz model for swollen clays
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膨胀粘土 wigner-seitz 模型的非线性泊松-玻尔兹曼理论
DOI：
10.1103/physreve.61.1634
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发表时间：
1999
期刊：
影响因子：
--
通讯作者：
J. Hansen
中科院分区：
文献类型：
--
作者：
R. L. Carvalho;E. Trizac;J. Hansen
在维格纳 - 赛茨（Wigner - Seitz）胞元模型内对有限尺寸的盘状锂皂石黏土片层的堆叠体进行了研究。在原始模型描述中，每个胞元是一个圆柱体，其中心包含一个同轴的片层，以及微观的同离子和反离子的整体电荷中性分布。静电势分布的非线性泊松 - 玻尔兹曼（PB）方程在一种高效的格林函数公式下进行数值求解。线性化泊松 - 玻尔兹曼（LPB）理论的先前预测在定性层面得到了证实，但在片层所带电荷的物理相关值处，发现PB理论和LPB理论之间存在较大的定量差异。一种在线性化层面处理边缘效应的混合理论给出了良好的势分布。在PB理论下计算的两个同轴片层之间的力比LPB理论预测的要小一个数量级。
Swollen stacks of finite-size disclike Laponite clay platelets are investigated within a Wigner-Seitz cell model. Each cell is a cylinder containing a coaxial platelet at its center, together with an overall charge-neutral distribution of microscopic co and counterions, within a primitive model description. The nonlinear Poisson-Boltzmann (PB) equation for the electrostatic potential profile is solved numerically within a highly efficient Green's function formulation. Previous predictions of linearized Poisson-Boltzmann (LPB) theory are confirmed at a qualitative level, but large quantitative differences between PB and LPB theories are found at physically relevant values of the charge carried by the platelets. A hybrid theory treating edge effect at the linearized level yields good potential profiles. The force between two coaxial platelets, calculated within PB theory, is an order of magnitude smaller than predicted by LPB theory.