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Zeta potential determination by streaming current modelization and measurement in electrophoretic microfluidic systems
Author(s) -
Renaud Louis,
Kleimann Pascal,
Morin Pierre
Publication year - 2004
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.200305696
Subject(s) - streaming current , microfluidics , zeta potential , electrophoresis , capillary electrophoresis , current (fluid) , analytical chemistry (journal) , microsystem , lab on a chip , poisson–boltzmann equation , surface charge , nanotechnology , materials science , chemistry , electrokinetic phenomena , chromatography , physics , thermodynamics , ion , organic chemistry , nanoparticle
Electrophoresis in capillary and microfluidic systems, used in analytical chemistry to separate charged species, are quite sensitive to surface phenomena in terms of separation performances. In order to improve theses performances, new surface functionalization techniques are required. There is a need for methods to provide fast and accurate quantification about surface charges at liquid/solid interfaces. We present a fast, simple, and low‐cost technique for the measurement of the zeta‐potential, via the modelization and the measurement of streaming currents. Due to the small channel cross section in microfluidic devices, the streaming current modelization is easier than the streaming potential measurement. The modelization combines microfluidic simulations based on the Navier‐Stokes equation and charge repartition simulations based on the Poisson‐Boltzmann equation. This method has been validated with square and circular cross section shape fused‐silica capillaries and can be easily transposed to any lab‐on‐chip microsystems.