Electroosmotic flows in axisymmetric capillaries with random zeta potentials were shown in [1] to exhibit axial velocity fluctuations about the mean plug flow. In this note we address the calculation of Taylor dispersion in such flows, and highlight the important differences between cross-sectional averaging (as usually used for dispersion problems) and ensemble averaging (as used in [1]).

DOI: 10.1002/elps.202000086 The cover picture shows the determination of four alkyl sulfate (AS) surfactants (C14, C12, C10, and C8) by capillary electrophoresis (CE) after preconcentration simultaneous adsorption AS on Al2O3 surface. EOF electroosmotic flow (EOF) at high pH pushes move to contactless conductivity detector (C4D). electropherograms show separation in order C14, C8.

A theoretical model of the EOF and hydrodynamic flow in wide closed cylindrical capillaries, after the application of a stepwise voltage, is developed. Analytical expressions have been obtained as a sum of the solutions for the direct flow and backflow in both periodical and aperiodical regimes with arbitrary pulse/pulse or pulse/pause durations and amplitudes. The numerical analysis, performed...

numerical investigation of 3d electrokinetic mixing through micromixer has performed both qualitatively and quantitatively. in order to reduce numerical expenses of 3d flows, we implement the helmholtz-smoluchowski method for the numerical modeling of electroosmotic flows. according to the previous study of electrokinetic mixing inside the heterogeneous microchannels, existence of the vortexes ...

The alternating current electroosmotic flow of a non-Newtonian power-law fluid is studied in a circular microchannel. A numerical method is employed to solve the non-linear Poisson-Boltzmann and the momentum equations. The main parameters which affect the flow field are the flow behavior index, the dimensionless zeta potential and the dimensionless frequency. At very low dimensionless frequenci...

A numerical study of 3D electrokinetic flows through micromixers was performed. The micromixers considered here consisted of heterogeneous rectangular microchannels with prescribed patterns of zeta-potential at their walls. Numerical simulation of electroosmotic flows within heterogeneous channels requires solution of the Navier-Stokes, Ernest-Plank and species concentration equations. It is kn...

The aim of this work was to find a relationship between electroosmotic flow (EOF) velocity of the mobile phase in pressurized planar electrochromatography (PPEC) and physicochemical properties like zeta potential, dielectric constant, and viscosity of the mobile phase as well as its composition. The study included different types of organic modifiers (acetonitrile, methanol, ethanol, acetone, f...

We have developed a quantitative immunoassay chip targeting point-of-care testing. To implement a lateral flow immunoassay, a glass fiber sheet was chosen as the material for the microfluidic channel in which the negative charge on the fiber surfaces efficiently generates the electroosmotic flow (EOF). The EOF, in turn, allows controllable bound/free separation of antigen/antibody interactions ...