The effect of electrode kinetics on electrophoretic forces.
The effect of electrode kinetics on electrophoretic forces.
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电极动力学对电泳力的影响。
DOI：
10.1016/j.jcis.2012.10.066
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发表时间：
2013
影响因子：
9.9
通讯作者：
D. Prieve
中科院分区：
文献类型：
--
作者：
Reza M. Rock;P. Sides;D. Prieve
电场通常用于在电极表面上存款胶体颗粒，甚至可以用于定向组装。当粒子接近壁面时，每个粒子下方的电场发生变化;壁面的接近打破了前后对称性，并驱动复杂的流动，对粒子施加力。虽然已经部分地分析了两种极限情况，即恒定的电极电位和均匀的电流密度，但是还没有探索全部问题。在这里，在粒子和电极之间的区域中的电渗流进行了分析，并计算任意电极动力学边界条件下的力。采用有限元分析来探讨粒子下方的电流分布对作用于其上的净力的影响。先前建立的无量纲动力学参数用于在两种极限情况之间进行缩放。粒子上的力比体电泳力大一个数量级，并且当粒子接近电极时对粒子下方的电流分布非常敏感。
Electric fields are commonly used to deposit colloidal particles on electrode surfaces and can even be used in directed assembly. The electric field beneath each particle changes as the particle approaches the wall; the proximity of the wall breaks the fore/aft symmetry and drives complicated flows that exert forces on the particle. While two limiting cases have been partially analyzed, constant electrode potential and uniform current density, the full problem has not been explored. Here, the electroosmotic flows in the region between the particle and the electrode are analyzed and the forces are computed for arbitrary electrode kinetic boundary conditions. Finite element analysis is employed to explore the effect of the current distribution beneath a particle on the net force acting on it. Previously established dimensionless kinetic parameters are used to scale between the two limiting cases. The forces on particles are an order of magnitude larger than the bulk electrophoretic force and are profoundly sensitive to the current distribution beneath the particle as it approaches the electrode.