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Accueil du site > Publications > Archives 2004-2010 > 2007 > Evidence for three-dimensional unstable flows in shear-banding wormlike micelles

Evidence for three-dimensional unstable flows in shear-banding wormlike micelles

L. Bécu, D. Anache, S. Manneville, and A. Colin — Phys. Rev. E 76, 011503 (2007)

24 juillet 2007

We report on an experimental study of the shear-banding phenomenon in the concentrated wormlike micellar system CTAB at 20 wt. % in D2O. Time-resolved velocity profiles are recorded using ultrasonic velocimetry simultaneously to global rheological data. Our results confirm the studies performed previously by Fischer and Callaghan [Phys. Rev. E 64, 011501 -(2001)]. Time averaged velocity profiles display an unsheared ?nematic gel ?. In the range of applied shear rate, the flow field exhibits very fast temporal fluctuations. Suspicions for the presence of three-dimensional flow are evidenced and possible causes for a three-dimensional instability are discussed together with the coupling of wall slip to bulk dynamic.

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