化工学报 ›› 2013, Vol. 64 ›› Issue (5): 1743-1749.DOI: 10.3969/j.issn.0438-1157.2013.05.033

• 表面与界面工程 • 上一篇    下一篇

压力驱动微流道内流动电势及壁面滑移效应

刘莹1, 谭德坤1,2   

  1. 1. 南昌大学机电工程学院, 江西 南昌 330031;
    2. 南昌工程学院信息学院, 江西 南昌 330099
  • 收稿日期:2012-09-01 修回日期:2012-12-17 出版日期:2013-05-05 发布日期:2013-05-05
  • 通讯作者: 刘莹
  • 作者简介:刘莹(1957-),女,博士,教授。
  • 基金资助:

    国家自然科学基金重点项目(50730007)。

Streaming potential and wall slip effects on pressure-driven microchannel flow

LIU Ying1, TAN Dekun1,2   

  1. 1. School of Mechanical & Electrical Engineering, Nanchang University, Nanchang 330031, Jiangxi, China;
    2. School of Information Engineering, Nanchang Institute of Technology, Nanchang 330099, Jiangxi, China
  • Received:2012-09-01 Revised:2012-12-17 Online:2013-05-05 Published:2013-05-05
  • Supported by:

    supported by the National Natural Science Foundation of China(50730007).

关键词: 流动电势, 壁面滑移效应, zeta电势, 动电参数, 微流道

Abstract: This study investigated the streaming potential and wall slip effects on pressure-driven liquid flow in hydrophobic microchannels.The Poisson-Boltzmann equation for the electrical double layer(EDL)and Navier-Stokes equation for incompressible viscous fluid were established.For those microchannels with high wall zeta potential, the traditional Debye-H點kel linear approximation for solving the potential distributions of EDL would produce big error, therefore, analytical expression for potential distributions and Navier slip boundary condition were introduced to solve the N-S equation analytically, then analytical solution of streaming potential could be obtained by using the electrical current balancing condition.The influences of electrokinetic parameter(K), wall zeta potential and slip coefficient on streaming potential and velocity distributions were discussed in detail.The results showed that streaming potential decreased with increasing electrokinetic parameter, while increased significantly with increasing slip coefficient.It also tended to reach a maximum value at a certain zeta potential and then decreased rapidly with increasing zeta potential.Streaming potential and wall slip both affected fluid flow in microchannels, the former retained the development of liquid flow, but the latter accelerated flow velocity.Wall slip effect played a major role at lower zeta potentials, that is, flow velocity increased at lower zeta potentials when the combined effects of streaming potential and hydrodynamic slippage appeared in microchannels.Wall slip velocity gradually reduced to zero at higher zeta potential, then wall slip effect on pressure-driven flow in microchannels could be ignored.

Key words: streaming potential, wall slip effect, zeta potential, electrokinetic parameter, microchannels

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