Wall effects in microchannel-based macromolecular separation under electromagnetohydrodynamic influences

Abstract

The present paper aims to develop a theoretical model to highlight the influences of the near-wall interaction potentials and the consequent migrative fluxes on the size-based separation of macromolecules in microchannels subject to combined electromagnetohydrodynamic influences. It is established that the speed of traverse and the extent of spreading (dispersion) of the macromolecular bands is effectively determined on the basis of the macromolecular size relative to the channel height and the extent of near-wall interactions. It is demonstrated that because of the near-wall effects, macromolecular pairs with less disparities in sizes give rise to higher values of resolution.

Electroosmotically driven capillary transport of typical non-Newtonian biofluids in rectangular microchannels

“…Certain critical features of electrokinetics [33][34][35][36][37][38][39][40][41] and contact angle characteristics [42] are considered. Closed-form expressions are derived for the various driving and retarding forces, in accordance with a power-law constitutive model.…”

Transient MHD heat transfer and entropy generation in a microparallel channel combined with pressure and electroosmotic effects

“…externally imposed vertical magnetic field and obtained optimized flow rates. The wall effects of this problem were also studied by Paul and Chakraborty [43]. Das et al [44] analytically examined the implications of spatially varying magnetic field on MHD transport in narrow fluidic confinements and magnetophoretic particle transport.…”

Influence of Streaming Potential on the Transport and Separation of Charged Spherical Solutes in Nanochannels Subjected to Particle−Wall Interactions

“…In eq , ϕ denotes the potential developed within the system so that one can write ∇ normalϕ = − E normalS î + ∂ normalψ ∂ y ĵ In eq , we consider the particle velocities, u P and v P , to be u P = u + u rel, x ≈ u ( u rel, x , which is the x component of the particle velocity relative to the flow velocity, is virtually negligible because the rotational effects of the particles are not considered to be important in the present context) and ν P = ν + ν rel, y = ν rel, y (expressions for v rel, y , the transverse velocity of analytes relative to the background flow, may be derived by considering the van der Waals (vdW) and EDL interaction potentials). ,− Accordingly, we may write v r e l , y = − ∂ φ W ∂ y 6 π μ R P where φ w is the wall−analyte interaction potential primarily contributed by the EDL and vdW interactions between the analytes and the channel walls. Thus, normalφ normalW = normalφ normalD normalL + normalφ normalv normald normalW Appropriate expressions for these potentials are as follows − normalφ normalD normalL -.15em = 32 normalε 0 …”