Revisit of wall-induced lateral migration in particle electrophoresis through a straight rectangular microchannel: Effects of particle zeta potential
Revisit of wall-induced lateral migration in particle electrophoresis through a straight rectangular microchannel: Effects of particle zeta potential
复制标题
重新审视直矩形微通道中粒子电泳中壁诱导的横向迁移：粒子 zeta 电位的影响
DOI：
10.1002/elps.201800198
复制
发表时间：
2019-03-01
期刊：
影响因子：
2.9
通讯作者：
Xuan, Xiangchun
中科院分区：
文献类型：
--
作者：
Liu, Zhijian;Li, Di;Xuan, Xiangchun
以前的研究已经报道了颗粒电泳会通过一个直的矩形微通道发生横向迁移。这种现象源于固有的壁面感应电升，可以用来聚焦和分离微流体应用中的颗粒。最近发现，这种介电泳样的力随着缓冲液浓度的变化而变化。在这项工作中，我们证明了粒子Zeta势对壁感应电升力也有显著的影响。在相同的动电动流条件下，我们对具有不同表面电荷的等尺寸聚苯乙烯颗粒的横向迁移进行了实验研究。令人惊讶的是，对于电动运动较快的粒子，观察到了增强的聚焦，这表明具有较小Zeta电位的粒子的电动升力要大得多。我们推测这一现象可能与颗粒表面导电性有关，颗粒表面导电性是颗粒和流体性质的强烈函数。
Previous studies have reported a lateral migration in particle electrophoresis through a straight rectangular microchannel. This phenomenon arises from the inherent wall-induced electrical lift that can be exploited to focus and separate particles for microfluidic applications. Such a dielectrophoretic-like force has been recently found to vary with the buffer concentration. We demonstrate in this work that the particle zeta potential also has a significant effect on the wall-induced electrical lift. We perform an experimental study of the lateral migration of equal-sized polystyrene particles with varying surface charges under identical electrokinetic flow conditions. Surprisingly, an enhanced focusing is observed for particles with a faster electrokinetic motion, which indicates a substantially larger electrical lift for particles with a smaller zeta potential. We speculate this phenomenon may be correlated with the particle surface conduction that is a strong function of particle and fluid properties.