Physics of Complex Fluids, Department of Science and Technology, IMPACT and MESA+ Institute, University of Twente, Enschede, The Netherlands.
Electrophoresis. 2010 Jan;31(3):563-9. doi: 10.1002/elps.200900603.
We study EOF through microchannels, made of glass or glass-PDMS, by displacing an electrolyte solution at given concentration with the same electrolyte at a different concentration via an external electric field. When a constant voltage is applied over the channel, the electric current through the channel varies during the displacement process. We propose a simple analytical model that describes the time dependence of the current regardless of the concentration ratio chosen. With this model, which is applicable beyond the Debye-Hückel limit, we are able to quantify the EOF velocity and to determine the surface charge on the microchannel walls from the measured current behavior, as well as the zeta potential at given local electrolyte concentration.
我们通过微通道（由玻璃或玻璃-PDMS 制成）研究 EOF，通过外部电场将给定浓度的电解质溶液置换为不同浓度的相同电解质。当在通道上施加恒定电压时，通道中的电流在置换过程中会发生变化。我们提出了一个简单的分析模型，该模型可以描述与所选择的浓度比无关的电流随时间的变化。通过这个模型（它适用于超越德拜-休克尔极限的情况），我们能够量化 EOF 速度，并根据测量的电流行为确定微通道壁的表面电荷，以及给定局部电解质浓度下的 ζ 电势。
