Nonlocal effects in flows of wormlike micellar solutions.
The flow curve of wormlike micelles usually exhibits a stress plateau sigma* separating high and low viscosity branches, leading to shear-banded flows. We study the flow of semidilute wormlike micellar systems in a confined geometry: a straight microchannel. We characterize their local rheology thanks to particle image velocimetry. We show that flow curves cannot be described by a simple constitutive equation linking the local shear stress to the local shear rate. We demonstrate the existence of nonlocal effects in the flow of wormlike micellar systems and make use of a theoretical framework allowing the measurement of correlation lengths.
Masselon
Chloé
C
LOF, unité mixte CNRS-Rhodia-Bordeaux 1, 178 avenue du Docteur Schweitzer, Pessac Cedex, France. chloe.masselon-exterieur@eu.rhodia.com
Salmon
Jean-Baptiste
JB
Colin
Annie
A