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Merging Ion Concentration Polarization between Juxtaposed Ion Exchange Membranes to Block the Propagation of the Polarization Zone
Published on: February 23, 2017
Concentration polarization and nonequilibrium electroosmotic slip in dense multiparticle systems
Ivo Nischang1, Udo Reichl, Andreas Seidel-Morgenstern
1Institut für Verfahrenstechnik, Otto-von-Guericke-Universität Magdeburg, Magdeburg, Germany.
Langmuir : the ACS Journal of Surfaces and Colloids
|August 9, 2007
Summary
Electrical field-induced concentration polarization (CP) creates nonequilibrium electroosmotic slip in cation-exchange particle beds. This phenomenon, studied via microscopy and flow dynamics, leads to nonlinear electroosmotic flow (EOF) in macroporous regions.
Area of Science:
- Electrokinetics
- Colloid Science
- Transport Phenomena
Background:
- Concentration polarization (CP) is crucial in ion-exchange systems.
- Electroosmotic flow (EOF) is influenced by electrical fields and particle properties.
- Understanding CP and EOF in porous media is vital for applications like filtration and sensing.
Purpose of the Study:
- To investigate electrical field-induced CP and CP-based nonequilibrium electroosmotic slip.
- To correlate local CP dynamics with macroscopic EOF nonlinearity.
- To analyze the impact of multiparticle effects on CP and slip in fixed beds.
Main Methods:
- Confocal laser scanning microscopy (CLSM) for visualizing local CP.
- Macroscopic electroosmotic flow (EOF) dynamics measurements.
- Study of fixed beds with strong cation-exchange particles.
Main Results:
- CP zones (depleted and enriched) form at particle interfaces under an electrical field.
- Nonlinear EOF arises from induced nonequilibrium electrical double layers in depleted CP zones.
- Multiparticle interactions significantly modulate CP patterns and electroosmotic slip intensity.
Conclusions:
- Local CP dynamics directly correlate with the onset of nonlinear EOF.
- Nonequilibrium electroosmotic slip is a key factor in nonlinear EOF in these systems.
- Particle packing and interactions play a significant role in CP and EOF behavior.
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