Dresden 2011 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 35: Poster: Micro- and Nanofluidics

CPP 35.23: Poster

Mittwoch, 16. März 2011, 17:00–19:00, P2

Influence of an electric field on the two phase flows in porous media — •Benoît Semin, Matthias Schröter, and Jean-Christophe Baret — Max-Planck Institut für Dynamik und Selbstorganisation, 37073 Göttingen, Germany

The use of an electric field to enhance oil recovery from porous media has been reported at both the sample and the field scales [1]. Here, we present an experimental study of this effect at the pore scale. To control and visualize the flow, we use microfluidic devices in which a model porous media is embedded. The latter is either an irregular array of pillars (2D) or a chamber filled with glass beads (3D). This model porous media is first filled with the wetting fluid (fluorinated oil) and then the non-wetting fluid (aqueous solution) is injected. The aqueous solution is dyed to allow for the measurement of the aqueous solution and oil saturations. An electric field is applied using electrodes patterned on the microfluidic device and the influence of the external electric field on the residual oil saturation is investigated. The coupling between the flow and the electric field can involve several physical mechanisms such as eletro-osmosis, electrowetting and dielectrophoresis [2]. The variation of the fluid properties (salt concentration, permittivity) and of the electric field (magnitude and frequency) can be used to determine the dominant mechanism on the oil retention. [1] Wittle and Bell, US Patent 7325604 (2008) [2] Tabeling, Introduction to Microfluidics (2006)