Impact of network heterogeneity on electrokinetic transport in porous media
Name
1901.02525.pdf
Description
Submitted version
Size
6.37 MB
Format
Unknown
Checksum (MD5)
8858540becb558269af8267c12451e0b
Author(s)
Alizadeh, Shima
Bazant, Martin Z
Mani, Ali
Date Issued
2019
Journal
Journal of Colloid and Interface Science
Publisher
Elsevier BV
Version
Original manuscript
Abstract
© 2019 Elsevier Inc. We present a numerical study of electrokinetic transport in porous media, focusing on the role of heterogeneity in a porous microstructure on ion concentration polarization and over-limiting current. For simplicity, the porous medium is modeled as a network of long, thin charged cylindrical pores, each governed by one-dimensional effective transport equations. For weak surface conduction, when sufficiently large potential is applied, we demonstrate that electrokinetic transport in a porous network can be dominated by electro-convection via internally induced flow loops, which is not properly captured by existing homogenized models. We systematically vary the topology and “accessivity” of the pore network and compare with simulations of traditional homogenized parallel-pore (capillary-bundle) models, in order to reveal the effects of regular and hierarchical connectivity. Our computational framework sheds light on the complex physics of electrokinetic phenomena in microstructures and may be used to design porous media for applications, such as water desalination and purification by shock electrodialysis.
MIT Department
Massachusetts Institute of Technology. Department of Chemical Engineering
Massachusetts Institute of Technology. Department of Mathematics
Terms of Use
Creative Commons Attribution-NonCommercial-NoDerivs License
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1016/j.jcis.2019.06.023
