TY - JOUR
T1 - Mass transport in oscillatory electroosmotic viscoelectric flow in a hydrophobic microchannel with steric effect
AU - Baños, R.
AU - Arcos, J.
AU - Bautista, O.
AU - Méndez, F.
N1 - Publisher Copyright:
© 2023 The Japan Society of Fluid Mechanics and IOP Publishing Ltd.
PY - 2023/2/1
Y1 - 2023/2/1
N2 - We conduct a numerical study of viscoelectric and steric effects on an oscillatory electroosmotic flow (OEOF) and their impact on the mass transport of a passive solute through a hydrophobic microchannel. In many applications of electroosmosis, zeta potentials as high as 100–200 mV can be found; in such a situation, the Debye–Hückel approximation is no longer valid, and the steric effect must be considered because the crowding of finite-sized ions close to the microchannel walls. In addition to the previous effect, the local viscosity can be increased due to the viscoelectric effect for strong electric potentials induced in the electric double layer. Earlier works have studied the mass transfer caused by an OEOF; however, the combined effects' influence has not been considered. This research suggests that under an appropriate combination of the viscoelectric and steric effects, together with the microchannel hydrophobicity, the mass transport can be controlled and notably enhanced compared with the case where such effects are disregarded. An interesting behavior occurs for relatively high values of the steric factor ν, where there is a linear dependence between the mass transport $\tilde{Q}$ and the viscoelectric factor $\tilde{f}$; in contrast, for low values of ν, the relationship $\tilde{Q}-\tilde{f}$ is non-linear.
AB - We conduct a numerical study of viscoelectric and steric effects on an oscillatory electroosmotic flow (OEOF) and their impact on the mass transport of a passive solute through a hydrophobic microchannel. In many applications of electroosmosis, zeta potentials as high as 100–200 mV can be found; in such a situation, the Debye–Hückel approximation is no longer valid, and the steric effect must be considered because the crowding of finite-sized ions close to the microchannel walls. In addition to the previous effect, the local viscosity can be increased due to the viscoelectric effect for strong electric potentials induced in the electric double layer. Earlier works have studied the mass transfer caused by an OEOF; however, the combined effects' influence has not been considered. This research suggests that under an appropriate combination of the viscoelectric and steric effects, together with the microchannel hydrophobicity, the mass transport can be controlled and notably enhanced compared with the case where such effects are disregarded. An interesting behavior occurs for relatively high values of the steric factor ν, where there is a linear dependence between the mass transport $\tilde{Q}$ and the viscoelectric factor $\tilde{f}$; in contrast, for low values of ν, the relationship $\tilde{Q}-\tilde{f}$ is non-linear.
KW - hydrophobic microchannel
KW - mass transport rate
KW - oscillatory electroosmotic flow
KW - steric effect
KW - viscoelectric effect
UR - http://www.scopus.com/inward/record.url?scp=85147139805&partnerID=8YFLogxK
U2 - 10.1088/1873-7005/acb170
DO - 10.1088/1873-7005/acb170
M3 - Artículo
AN - SCOPUS:85147139805
SN - 0169-5983
VL - 55
JO - Fluid Dynamics Research
JF - Fluid Dynamics Research
IS - 1
M1 - 015502
ER -