Yan Deguang, Yang Chun, Nguyen Nam-Trung, Huang Xiaoyang
School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore.
Electrophoresis. 2006 Feb;27(3):620-7. doi: 10.1002/elps.200500713.
The zeta potentials of channel surfaces and tracer particles are of importance to the design of electrokinetic microfluidic devices, the characterization of channel materials, and the quantification of the microparticle image velocimetry (microPIV) measurement of EOFs. A method is proposed to simultaneously measure the zeta potentials of the channel surface and the tracer particles in aqueous solutions using the microPIV technique. Through the measurement of the steady velocity distributions of the tracer particles in both open- and closed-end rectangular microchannels under the same water chemistry condition, the electrophoretic velocity of the tracer particles and the EOF field of the microchannel are determined using the expressions derived in this study for the velocity distributions of charged tracer particles in the open- and closed-end rectangular microchannels. Thus, the zeta potentials of the tracer particles and the channel surfaces are simultaneously obtained using the least-square method to fit the microPIV measured velocity distribution of the tracer particles. Measurements were carried out with a microPIV system to determine the zeta potentials of the channel wall and the fluorescent tracer particles in deionized water and sodium chloride and boric acid solutions of various concentrations.
通道表面和示踪粒子的zeta电位对于电动微流控装置的设计、通道材料的表征以及电渗流（EOF）的微粒图像测速法（microPIV）测量的量化都很重要。本文提出了一种使用microPIV技术同时测量水溶液中通道表面和示踪粒子zeta电位的方法。通过在相同水化学条件下测量开放式和封闭式矩形微通道中示踪粒子的稳态速度分布，利用本研究中推导的关于开放式和封闭式矩形微通道中带电示踪粒子速度分布的表达式，确定示踪粒子的电泳速度和微通道的EOF场。因此，使用最小二乘法拟合示踪粒子的microPIV测量速度分布，同时获得示踪粒子和通道表面的zeta电位。使用microPIV系统进行测量，以确定去离子水以及各种浓度的氯化钠和硼酸溶液中通道壁和荧光示踪粒子的zeta电位。
