Shear-induced fragmentation of Laponite suspensions

Abstract : Simultaneous rheological and velocity profile measurements are performed in a smooth Couette geometry on Laponite suspensions seeded with glass microspheres and undergoing the shear-induced solid-to-fluid (or yielding) transition. Under these slippery boundary conditions, a rich temporal behaviour is uncovered, in which shear localization is observed at short times, that rapidly gives way to a highly heterogeneous flow characterized by intermittent switching from plug-like flow to linear velocity profiles. Such a temporal behaviour is linked to the fragmentation of the initially solid sample into blocks separated by fluidized regions. These solid pieces get progressively eroded over time scales ranging from a few minutes to several hours depending on the applied shear rate $\dot{\gamma}$. The steady-state is characterized by a homogeneous flow with almost negligible wall slip. The characteristic time scale for erosion is shown to diverge below some critical shear rate $\dot{\gamma}^\star$ and to scale as $(\dot{\gamma}-\dot{\gamma}^\star)^{-n}$ with $n\simeq 2$ above $\dot{\gamma}^\star$. A tentative model for erosion is discussed together with open questions raised by the present results.
Type de document :
Article dans une revue
Soft Matter, Royal Society of Chemistry, 2009, 5 (1), pp.3026-3037. 〈10.1039/b906274b〉
Liste complète des métadonnées

Littérature citée [30 références]  Voir  Masquer  Télécharger

https://hal-ens-lyon.archives-ouvertes.fr/ensl-00371654
Contributeur : Sébastien Manneville <>
Soumis le : lundi 30 mars 2009 - 14:10:33
Dernière modification le : jeudi 19 avril 2018 - 14:54:03
Document(s) archivé(s) le : jeudi 10 juin 2010 - 19:10:12

Fichiers

laponite_arxiv.pdf
Fichiers produits par l'(les) auteur(s)

Identifiants

Collections

Citation

Thomas Gibaud, Catherine Barentin, Nicolas Taberlet, Sébastien Manneville. Shear-induced fragmentation of Laponite suspensions. Soft Matter, Royal Society of Chemistry, 2009, 5 (1), pp.3026-3037. 〈10.1039/b906274b〉. 〈ensl-00371654〉

Partager

Métriques

Consultations de la notice

232

Téléchargements de fichiers

104