Numerical modelling of nonequilibrium electrokinetic phenomena in porous media containing ion-permselective spatial domains

• Applicant: Dr.-Ing. Dzmitry Hlushkou
• Subject Area: Chemical and Thermal Process Engineering
• Term: from 2005 to 2009
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 18407768

• Final Report Year: 2009

Final Report Abstract

This work was concerned with a three-dimensional, high-resolution numerical simulation of electrokinetic transport through porous media containing discrete ion-permselective, i.e., charge-selective spatial domains, covering coupled mass and charge transport through nanopores in ion-exchange membranes (flat interface) and porous particles in fixed beds (curved interfaces). By implementing novel, advanced numerical schemes (lattice-Boltzmann method and lattice-based algorithms) for a solution of the coupled Poisson-Nernst-Planck and electrohydrodynamic problems in three-dimensional porous media, it was possible to correlate microscopic details of a solid-liquid interface (surface charge density and ionic strength) with the electrokinetics and hydrodynamics evolving on mesoscopic length scales, as well as with the macrotransport theory. Particular attention was devoted to the spatio-temporal dynamics of concentration polarisation.and extended, electrical field-induced space charge regions which may develop due to coupled mass and charge transport normal to a charge-selective interface under the influence of externally applied electrical fields. These phenomena were analysed and tailored for reducing limitations to coupled mass and charge transport in porous media arising from concentration polarisafion.

Publications

• Pore-Scale Dispersion in Electrokinetic Flow through a Random Sphere Packing Analytical Chemistry, 2007, 79, 113-121.
  D. Hlushkou, S. Khirevich, V. Apanasovich, A. Seidel-Morgenstern, and U. Tallarek
  
• Electrohydrodynamics around single ion-permselective glass beads fixed in a microfluidic device Microfluidics and Nanofluidics, 2008, 4, 471-485.
  S. Ehlert, D. Hlushkou, and Ulrich Tallarek
  
• Electrokinetics in microfluidic channels containing a floating electrode Journal of the American Chemical Society, 2008, 130,10480-1.
  R. Dhopeshwarkar, D. Hlushkou, M. Nguyen, U. Tallarek, and R. M. Crooks
  
• The influence of membrane ion-permselectivity on electrokinetic concentration enrichment In membrane-based preconcentration units Lab on a Chip, 2008, 8, 1153-1162.
  D. Hlushkou, R. Dhopeshwarkar, R. M. Crooks, and U. Tallarek
  
• Transient Effects on MicroChannel Electrokinetic Filtering with an lon-Permselective Membrane Analytical Chemistry. 2008, 80, 1039-1048.
  R. Dhopeshwarkar, R. M. Crooks, D. Hlushkou, and U. Tallarek