Aging and yielding in a sheared AOT/iso-octane/water lyotropic lamellar phase.
We define a creep-flow-based measurement procedure to allow reliable and reproducible results on aging and yielding materials to be obtained. Investigation of the effects of different parameter such as the pre-shear time, the recovery time and the applied stress magnitude on the viscoelastic properties of a lyotropic liquid crystal phase is reported. Cryo-TEM observations indicate the formation of multiconnected bilayers at rest. Shearing the investigated material shows a propensity to acquire all the macroscopic properties of "soft jammed systems". These properties are then interpreted in terms of shear-induced structural rearrangement on the basis of cryofracture observation obtained at different times after the preshear imposed.
Laboratoire de Rhéologie UMR 5520, Domaine Universitaire, BP53, 38041, Grenoble Cedex 9, France. yann.auffret@ujf-grenoble.fr
Y
Y
Auffret
D C D
DC
Roux
N
N
El Kissi
F
F
Caton
I
I
Pignot-Paintrand
D E
DE
Dunstan
C
C
Rochas
D004143:Dioctyl Sulfosuccinic Acid / Q000737:chemistry*; D009795:Octanes / Q000737:chemistry*; D044367:Phase Transition; D015203:Reproducibility of Results; D013997:Time Factors; D014867:Water / Q000737:chemistry*
D009795:Octanes; D014867:Water; D004143:Dioctyl Sulfosuccinic Acid; C026728:octane