微通道收缩中粘弹性流体电泳的意外颗粒振动。
An unexpected particle oscillation for electrophoresis in viscoelastic fluids through a microchannel constriction.
机构信息
Department of Mechanical Engineering, Clemson University, Clemson, South Carolina 29634-0921, USA.
Department of Chemical and Biomolecular Engineering, and Center for Advanced Engineering Fibers and Films, Clemson University, Clemson, South Carolina 29634-0909, USA.
出版信息
Biomicrofluidics. 2014 Mar 3;8(2):021802. doi: 10.1063/1.4866853. eCollection 2014 Mar.
Electrophoresis plays an important role in many applications, which, however, has so far been extensively studied in Newtonian fluids only. This work presents the first experimental investigation of particle electrophoresis in viscoelastic polyethylene oxide (PEO) solutions through a microchannel constriction under pure DC electric fields. An oscillatory particle motion is observed in the constriction region, which is distinctly different from the particle behavior in a polymer-free Newtonian fluid. This stream-wise particle oscillation continues until a sufficient number of particles form a chain to pass through the constriction completely. It is speculated that such an unexpected particle oscillating phenomenon is a consequence of the competition between electrokinetic force and viscoelastic force induced in the constriction. The electric field magnitude, particle size, and PEO concentration are all found to positively affect this viscoelasticity-related particle oscillation due to their respective influences on the two forces.
电泳在许多应用中起着重要的作用，但迄今为止，它仅在牛顿流体中得到了广泛的研究。本工作通过在纯直流电场下在微通道收缩处首次实验研究了粘弹性聚乙烯氧化物（PEO）溶液中的颗粒电泳。在收缩区域观察到颗粒的振荡运动，这与无聚合物牛顿流体中的颗粒行为明显不同。这种流向的颗粒振荡一直持续到足够数量的颗粒形成一条链完全通过收缩处。据推测，这种意想不到的颗粒振荡现象是在收缩处产生的电动力量和粘弹性力之间竞争的结果。实验发现，电场强度、颗粒大小和 PEO 浓度都由于它们各自对两种力的影响而对这种与粘弹性有关的颗粒振荡产生积极影响。
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