TY - JOUR
T1 - Investigation of nanoscale electrohydrodynamic transport phenomena in charged porous materials
AU - Pivonka, Peter
AU - Smith, David
PY - 2005
Y1 - 2005
N2 - Depending on the permeability of porous materials, different mass transport mechanisms have to be distinguished. Whereas mass transport through porous media characterized by low permeabilities is governed by diffusion, mass transport through highly permeable materials is governed by advection. Additionally a large number of porous materials are characterized by the presence of surface charge which affects the permeability of the porous medium. Depending on the ion transport mechanism various phenomena such as co-ion exclusion, development of diffusion-exclusion potentials, and streaming potentials may be encountered. Whereas these various phenomena are commonly described by means of different transport models, a unified description of these phenomena can be made within the framework of electrohydrodynamics.In this paper the fundamental equations describing nanoscale multi-ion transport are given. These equations comprise the generalized Nernst-Planck equation, Gauss' theorem of electrostatics, and the Navier-Stokes equation. Various phenomena such as the development of exclusion potentials, diffusion-exclusion potentials, and streaming potentials are investigated by means of finite element analyses. Furthermore, the influence of the surface charge on permeability and ion transport are studied in detail for transient and steady-state problems. The nanoscale findings provide insight into events observed at larger scales in charged porous materials. Copyright (c) 2005 John Wiley & Sons, Ltd.
AB - Depending on the permeability of porous materials, different mass transport mechanisms have to be distinguished. Whereas mass transport through porous media characterized by low permeabilities is governed by diffusion, mass transport through highly permeable materials is governed by advection. Additionally a large number of porous materials are characterized by the presence of surface charge which affects the permeability of the porous medium. Depending on the ion transport mechanism various phenomena such as co-ion exclusion, development of diffusion-exclusion potentials, and streaming potentials may be encountered. Whereas these various phenomena are commonly described by means of different transport models, a unified description of these phenomena can be made within the framework of electrohydrodynamics.In this paper the fundamental equations describing nanoscale multi-ion transport are given. These equations comprise the generalized Nernst-Planck equation, Gauss' theorem of electrostatics, and the Navier-Stokes equation. Various phenomena such as the development of exclusion potentials, diffusion-exclusion potentials, and streaming potentials are investigated by means of finite element analyses. Furthermore, the influence of the surface charge on permeability and ion transport are studied in detail for transient and steady-state problems. The nanoscale findings provide insight into events observed at larger scales in charged porous materials. Copyright (c) 2005 John Wiley & Sons, Ltd.
U2 - 10.1002/nme.1353
DO - 10.1002/nme.1353
M3 - Article
SN - 0029-5981
VL - 63
SP - 1975
EP - 1990
JO - International Journal for Numerical Methods in Engineering
JF - International Journal for Numerical Methods in Engineering
IS - 14
ER -