Slow growth of the Rayleigh-Plateau instability in aqueous two phase systems

Slow growth of the Rayleigh-Plateau instability in aqueous two phase systems

Geschiere, S.D.
Ziemecka, I.
Van Steijn, V.
Koper, G.J.M.
Van Esch, J.H.
Kreutzer, M.T.

Applied Sciences

ChemE/Chemical Engineering

2012-04-06

This paper studies the Rayleigh-Plateau instability for co-flowing immiscible aqueous polymer solutions in a microfluidic channel. Careful vibration-free experiments with controlled actuation of the flow allowed direct measurement of the growth rate of this instability. Experiments for the well-known aqueous two phase system (ATPS, or aqueous biphasic systems) of dextran and polyethylene glycol solutions exhibited a growth rate of 1 s-1, which was more than an order of magnitude slower than an analogous experiment with two immiscible Newtonian fluids with viscosities and interfacial tension that closely matched the ATPS experiment. Viscoelastic effects and adhesion to the walls were ruled out as explanations for the observed behavior. The results are remarkable because all current theory suggests that such dilute polymer solutions should break up faster, not slower, than the analogous Newtonian case. Microfluidic uses of aqueous two phase systems include separation of labile biomolecules but have hitherto be limited because of the difficulty in making droplets. The results of this work teach how to design devices for biological microfluidic ATPS platforms.

adhesion
biochemistry
biological fluid dynamics
flow instability
microfluidics
molecular biophysics
polymer solutions
surface tension
viscosity

http://resolver.tudelft.nl/uuid:d9fad926-e61f-4b6d-aa6e-3ca13521d170

https://doi.org/10.1063/1.3700117

American Institute of Physics

1932-1058

http://bmf.aip.org/resource/1/biomgb/v6/i2/p022007_s1

Biomicrofluidics, 6 (2), 2012

Institutional Repository

journal article

© 2012 The Author(s)
American Institute of Physics