Renaud Louis, Kleimann Pascal, Morin Pierre
Laboratoire d'Electronique Nanotechnologies Capteurs (LENAC), Université Claude Bernard Lyon 1, Villeurbanne, France.
Electrophoresis. 2004 Jan;25(1):123-7. doi: 10.1002/elps.200305696.
Electrophoresis in capillary and microfluidic systems, used in analytical chemistry to separate charged species, are quite sensitive to surface phenomena in terms of separation performances. In order to improve theses performances, new surface functionalization techniques are required. There is a need for methods to provide fast and accurate quantification about surface charges at liquid/solid interfaces. We present a fast, simple, and low-cost technique for the measurement of the zeta-potential, via the modelization and the measurement of streaming currents. Due to the small channel cross section in microfluidic devices, the streaming current modelization is easier than the streaming potential measurement. The modelization combines microfluidic simulations based on the Navier-Stokes equation and charge repartition simulations based on the Poisson-Boltzmann equation. This method has been validated with square and circular cross section shape fused-silica capillaries and can be easily transposed to any lab-on-chip microsystems.
毛细管和微流控系统中的电泳用于分析化学中分离带电物质，就分离性能而言，对表面现象相当敏感。为了提高这些性能，需要新的表面功能化技术。需要有方法来快速准确地量化液/固界面处的表面电荷。我们通过对流动电流进行建模和测量，提出了一种快速、简单且低成本的测量zeta电位的技术。由于微流控装置中的通道横截面较小，流动电流建模比流动电位测量更容易。该建模结合了基于纳维-斯托克斯方程的微流控模拟和基于泊松-玻尔兹曼方程的电荷分布模拟。该方法已通过方形和圆形横截面形状的熔融石英毛细管得到验证，并且可以轻松应用于任何芯片实验室微系统。
