Vortex of viscoelastic fluid electroosmotic flow at the micro-nanochannel interface

The research on ion transport and vortex formation of viscoelastic fluids at the interface of micro-nanochannels may provide a new solution to improve the efficiency of analyte preconcentration in the ion depletion zone. The electroosmotic flow of a viscoelastic fluid in a nanochannel connecting two reservoirs was numerically investigated using the Navier-Stokes model, the Poisson-Nernst-Planck model, and the Oldroyd-B constitutive model. The results show that viscoelasticity suppresses the vortices in the ion depletion zone and breaks the symmetry of the vortices. Viscoelasticity also imparts a time dependence of vortex structure and velocity. When cKCl is 1 mM, the ratio of the average velocity at the upstream to the average velocity at the downstream for the viscoelastic fluid with the PAA concentration of 1000 ppm reaches 1.42, while it is only 0.70 for the Newtonian fluid. This study has positive significance for the development of nanochannel-based biosensing technology.

Automated summary

The research investigates the electroosmotic flow of viscoelastic fluids in nanochannels and its effects on ion transport and vortex formation. The results show that viscoelasticity suppresses vortices in the ion depletion zone and influences their symmetries and time-dependent properties. The improvement in analyte preconcentration efficiency and the implications for nanochannel biosensing technology highlight the significance of this study.