Mass transfer of a neutral solute in porous microchannel under streaming potential

Abstract

The mass transport of a neutral solute in a porous wall, under the influence of streaming field, has been analyzed in this study. The effect of the induced streaming field on the electroviscous effect of the fluid for different flow geometries has been suitably quantified. The overall electroosmotic velocity profile and expression for streaming field have been obtained analytically using the Debye-Huckel approximation, and subsequently used in the analysis for the mass transport. The analysis shows that as the solution Debye length increases, the strength of the streaming field and, consequently, the electroviscous effect diminishes. The species transport equation has been coupled with Darcy's law for quantification of the permeation rate across the porous wall. The concentration profile inside the mass transfer boundary layer has been solved using the similarity transformation, and the Sherwood number has been calculated from the definition. In this study, the variation of the permeation rate and solute permeate concentration has been with the surface potential, wall retention factor and osmotic pressure coefficient has been demonstrated for both the circular as well as rectangular channel cross-section.

Effect of electrolyte nature in mass transport of a neutral solute in a microtube with porous wall

“…Dispersion of solute in case of shear and electroosmotic flow in micro‐conduits with porous wall was theoretically studied by Dejam and his co‐workers . Theoretical studies were carried out to understand the flow and mass transport characteristics in case of a porous wall‐based microchannel enzyme bioreactors by Chen et al There are few works available in literature to quantify the transport of neutral solute in electroosmotic flow both in rectangular and tubular cross‐section microchannel with porous wall using Newtonian and non‐Newtonian rheology . However, the above works were carried out using 1:1 electrolyte.…”

Mass transfer of a neutral solute in polyelectrolyte grafted soft nanochannel with porous wall

“…In addition, in separation science and technology, flow through functionalized nanofiltration membranes can be modeled using the theory for solute transport through nanochannel. Transport phenomena in these systems have been theoretically studied for the case of microchannel/microtube at constant permeate flux , flow of neutral solutes , flow of solution containing asymmetric electrolyte , Newtonian and non‐newtonian fluid flow , generation of streaming potential and electroviscous effect , etc.…”

Electrohydrodynamic transport of non‐symmetric electrolyte through porous wall of a microtube

“…Heat transfer and fluid flow are much researched areas of microfluidics [5][6][7][8][9][10][11][12][13][14]. However, in spite of being a field of immense importance, mass transport in micro/nanofluidic conduits with porous wall has not attracted significant attention of research community and few works are available in this area [15][16][17][18][19]. One real life example of mass transport in micro/nanofluidics confinement with porous wall is transport of nutrients through microcirculation systems to organs.…”