Transient electro-osmotic flow in cylindrical microcapillaries containing salt-free medium.
Transient electro-osmotic flow in cylindrical microcapillaries containing salt-free medium.
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DOI：
10.1063/1.3064113
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发表时间：
2009-01
期刊：
影响因子：
3.2
通讯作者：
Shih-Hsiang Chang
中科院分区：
文献类型：
--
作者：
Shih-Hsiang Chang
针对恒定表面电荷密度和恒定表面电位，对通过含有无盐介质的圆柱形微毛细管的瞬态电渗流进行了理论研究。通过求解非线性泊松-玻尔兹曼方程和纳维-斯托克斯方程，得到了电势分布和瞬态电渗流速的精确解析解。基于这些结果，对瞬态电渗流的特性进行了系统的参数研究。圆柱形管中瞬态电渗流的一般行为与在含有电解质溶液的微通道中观察到的类似。然而，稳态电渗流在较高表面电荷下显着偏离典型的活塞流，并且由于反离子凝聚的影响，电渗迁移率的增加速率被强烈抑制。此外，还讨论了这些解决方案的适用范围。
A theoretical study on the transient electro-osmotic flow through a cylindrical microcapillary containing a salt-free medium is presented for both constant surface charge density and constant surface potential. The exact analytical solutions for the electric potential distribution and the transient electro-osmotic flow velocity are derived by solving the nonlinear Poisson-Boltzmann equation and the Navier-Stokes equation. Based on these results, a systematic parametric study on the characteristics of the transient electro-osmotic flow is detailed. The general behavior of transient electro-osmotic flow in a cylindrical tube is similar to that observed in a microchannel containing an electrolyte solution. However, the steady-state electro-osmotic flow significantly deviates from the typical plug flow at higher surface charge and the rate of increase in the electro-osmotic mobility is strongly suppressed due to the effect of counterion condensation. In addition, the applicability limit of these solutions is also discussed.