Laboratoire Matière et Systèmes Complexes

MSC : Sophie Asnacios.

Collaborations : F. Gobeaux 1, E. Belamie 2, G. Mosser 1, P. Davidson 3

1 Laboratoire de Chimie de la Matière Condensée de Paris, UMR 7574 CNRS, Université Pierre et Marie Curie.

2 Laboratoire "Matériaux du Vivant et Vectorisation" de l’Ecole Pratique des Hautes Etudes, Institut Charles Gerhardt, UMR 5253 CNRS, Ecole de Chimie Montpellier/UM2/UM1 8, rue de l’Ecole Normale, 34296 Montpellier Cedex 5.

3 Laboratoire de Physique des Solides, UMR 8502 CNRS, Université Paris Sud, Bât. 510, 91405 Orsay Cedex.

Study of complex fluids is of practical (oil recovery, injection molding, food industry, biology) and fundamental importance. Recently we studied the flow properties of concentrated solutions of collagen in creep experiments. We have shown that (i) this material flows like a liquid above a yield deformation and not above a yield stress as it is the case for a wide class of complex fluids; (ii) that the creep responses to distinct levels of stresses all collapse onto a master curve according to an original “time-stress” superposition principle (TSS) akin to the “time-temperature” superposition principle (TTS) well-known in polymer physics. Our current concern is now to assess whether strain-induced yielding and TSS apply to other materials. Another objective is to understand the structural features and the microscopic mechanisms underlying strain-induced yielding. Beyond its fundamental meaning, TSS could have practical interest since it allows to predict when the material will fluidize under any load.

F. Gobeaux, E. Belamie, G. Mosser, P. Davidson, S. Asnacios, "Power-law rheology and strain-induced yielding in acidic solutions of type I-collagen", Soft Matter 6 3769-3777 (2010).