Adsorption and depletion of polyelectrolytes from charged surfaces
Adsorption and depletion of polyelectrolytes from charged surfaces
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DOI：
10.1063/1.1580798
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发表时间：
2003-02
影响因子：
4.4
通讯作者：
A. Shafir;D. Andelman;R. Netz
中科院分区：
文献类型：
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作者：
A. Shafir;D. Andelman;R. Netz
提出了平均场理论和缩放参数来模拟从半稀溶液到带电表面的聚电解质吸附。利用平均场方程的数值解，我们证明了吸附只存在于低盐溶液中高电荷的聚电解质。得到了吸附层宽度和聚电解质吸附量的简单标度规律。在其他情况下，聚电解质链将从表面耗尽。在固定表面电位条件下，吸附-耗尽交叉尺度下的盐浓度为聚电解质的带电分数f与表面电位的乘积，而在固定表面电荷密度σ条件下，其尺度为σ2/3f2/3，与单链结果一致。
Mean-field theory and scaling arguments are presented to model polyelectrolyte adsorption from semidilute solutions onto charged surfaces. Using numerical solutions of the mean-field equations, we show that adsorption exists only for highly charged polyelectrolytes in low salt solutions. Simple scaling laws for the width of the adsorbed layer and the amount of adsorbed polyelectrolyte are obtained. In other situations the polyelectrolyte chains will deplete from the surface. For fixed surface potential conditions, the salt concentration at the adsorption–depletion crossover scales as the product of the charged fraction of the polyelectrolyte f and the surface potential, while for a fixed surface charge density, σ, it scales as σ2/3f2/3, in agreement with single-chain results.