Wall slip, shear banding, and instability in the flow of a triblock copolymer micellar solution

Sébastien Manneville (1) , Annie Colin (2) , Gilles Waton (3) , François Schosseler (3)

1 Phys-ENS - Laboratoire de Physique de l'ENS Lyon
2 LOF - Laboratoire du Futur
3 ICS - Institut Charles Sadron

The shear flow of a triblock copolymer micellar solution (PEO-PPO-PEO Pluronic P84 in brine) is investigated using simultaneous rheological and velocity profile measurements in the concentric cylinder geometry. We focus on two different temperatures below and above the transition temperature Tc which was previously associated with the apparition of a stress plateau in the flow curve. (i) At T=37.0 °CTc, the stress plateau is shown to correspond to stationary shear-banded states characterized by two high shear rate bands close to the walls and a very weakly sheared central band, together with large slip velocities at the rotor. In both cases, the high shear branch of the flow curve is characterized by flow instability. Interpretations of wall slip, three-band structure, and instability are proposed in light of recent theoretical models and experiments.

Keywords: Surfactant and micellar systems; Associated polymers; Material behavior; Non-Newtonian fluid flows; Acoustical measurements and instrumentation

Domains: Physics [physics]; Condensed Matter [cond-mat]; Soft Condensed Matter [cond-mat.soft]

Sébastien Manneville, Annie Colin, Gilles Waton, François Schosseler. Wall slip, shear banding, and instability in the flow of a triblock copolymer micellar solution. Physical Review E : Statistical, Nonlinear, and Soft Matter Physics, 2007, 75 (6), pp.061502. ⟨10.1103/PhysRevE.75.061502⟩. ⟨ensl-00526640⟩