Viscoelastic Effects on Dispersion due to Electroosmotic Flow with Variable Zeta Potential

Abstract -In this work the influence of viscoelasticity and wall zeta potential effects on the dispersion coefficient of an electroosmotic flow through a micro-channel is studied. The governing equations for the fluid are reduced in the limit of the lubrication approximation theory (LAT). For the symmetric electrolyte, the Poisson-Boltzmann equation was solved by considering the wall zeta potential changes axially by the relationship ( ) = 0 + ∆ sin 2 . Here 0 is a reference wall zeta-potential, ∆ is the amplitude of the fluctuations of the periodic function ( ), and are the axial variable and the micro-channel length, respectively. The simplified equations are solved numerically to determine the axial distribution of the dispersion coefficient as a function of the main parameters involved in the analysis