Nonlinear Smoluchowski slip velocity and micro-vortex generation
Nonlinear Smoluchowski slip velocity and micro-vortex generation
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DOI：
10.1017/s0022112002008662
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发表时间：
2002-06-25
影响因子：
3.7
通讯作者：
Chang, HC
中科院分区：
文献类型：
--
作者：
Ben, Y;Chang, HC
当在电解质溶液中对导电和离子选择性的多孔颗粒施加电场时，就会产生带有多余反离子的极化表面层。这一层的深度和穿过这一层的过电位V是颗粒表面上的法向电场j的函数。通过将离子通量方程和泊松方程转化为第二类Painleve方程，并通过分析后者的渐近解，我们得到了具有电动滑移长度β的大通量下的线性普适j-V关联。磁通诱导的表面极化产生了一个非线性的Smoluchowski滑移速度，该速度可以与颗粒的曲率相耦合，从而在微器件中产生微涡。在无旋电动势恒Zeta势和线性滑移速度的情况下，这样的涡旋是不可能的。
When an electric field is applied across a conducting and ion-selective porous granule in an electrolyte solution, a polarized surface layer with excess counter-ions is created. The depth of this layer and the overpotential V across this layer are functions of the normal electric field j on the granule surface. By transforming the ionic flux equations and the Poisson equation into the Painleve equation of the second type and by analysing the latter's asymptotic solutions, we derive a linear universal j-V correlation at large flux with an electrokinetic slip length beta. The flux-induced surface polarization produces a nonlinear Smoluchowski slip velocity that can couple with the granule curvature to produce micro-vortices in micro-devices. Such vortices are impossible in irrotational electrokinetic flow with a constant zeta-potential and a linear slip velocity.