Charge inversion at high ionic strength studied by streaming currents.
Charge inversion at high ionic strength studied by streaming currents.
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DOI：
10.1103/physrevlett.96.224502
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发表时间：
2006-06
影响因子：
8.6
通讯作者：
Frank H J van der Heyden;D. Stein;K. Besteman;S. Lemay;C. Dekker
中科院分区：
文献类型：
--
作者：
Frank H J van der Heyden;D. Stein;K. Besteman;S. Lemay;C. Dekker
我们报告了电荷反转，即多价抗衡离子存在下有效表面电荷的符号反转，适用于二价离子以及单价和多价离子混合物的生物学相关状态。利用流动电流，即扩散层中反电荷的压力驱动传输，我们发现在高浓度的二价离子下，矩形二氧化硅纳米通道中会发生电荷反转。发现强单价筛选可以取消电荷反转，恢复原始表面电荷极性。基于离子相关性的分析模型成功地描述了我们的观察结果。
We report charge inversion, the sign reversal of the effective surface charge in the presence of multivalent counterions, for the biologically relevant regimes of divalent ions and mixtures of monovalent and multivalent ions. Using streaming currents, the pressure-driven transport of countercharges in the diffuse layer, we find that charge inversion occurs in rectangular silica nanochannels at high concentrations of divalent ions. Strong monovalent screening is found to cancel charge inversion, restoring the original surface charge polarity. An analytical model based on ion correlations successfully describes our observations.