title: Effects of ionic concentration gradient on electroosmotic flow mixing in a microchannel.
abstract: Effects of ionic concentration gradient on electroosmotic flow (EOF) mixing of one stream of a high concentration electrolyte solution with a stream of a low concentration electrolyte solution in a microchannel are investigated numerically. The concentration field, flow field and electric field are strongly coupled via concentration dependent zeta potential, dielectric constant and electric conductivity. The results show that the electric field and the flow velocity are non-uniform when the concentration dependence of these parameters is taken into consideration. It is also found that when the ionic concentration of the electrolyte solution is higher than 1M, the electrolyte solution essentially cannot enter the channel due to the extremely low electroosmotic flow mobility. The effects of the concentration dependence of zeta potential, dielectric constant and electric conductivity on electroosmotic flow mixing are studied.
authors.affiliation: Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: Ran
authors.initials: R
authors.lastname: Peng
authors.affiliation: Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada. Electronic address: dongqing@uwaterloo.ca.
authors.forename: Dongqing
authors.initials: D
authors.lastname: Li
mesh_terms: D004553:Electric Conductivity; D008962:Models, Theoretical; D009994:Osmolar Concentration; D009995:Osmosis
keywords: Dielectric constant; Electroosmotic flow; Flow mixing; Ionic concentration; Zeta potential