Collective rearrangement at the onset of flow of a polycrystalline hexagonal columnar phase

Teresa Bauer (1) , Julian Oberdisse (1) , Laurence Ramos (1)

1 LCVN - Laboratoire des colloïdes, verres et nanomatériaux

Creep experiments on polycrystalline surfactant hexagonal columnar phases show a power law regime, followed by a drastic fluidization before reaching a final stationary flow. The scaling of the fluidization time with the shear modulus of the sample and stress applied suggests that the onset of flow involves a bulk reorganization of the material. This is confirmed by X-ray scattering under stress coupled to \textit{in situ} rheology experiments, which show a collective reorientation of all crystallites at the onset of flow. The analogy with the fracture of heterogeneous materials is discussed.

Domaines: Matière Molle [cond-mat.soft]

Teresa Bauer, Julian Oberdisse, Laurence Ramos. Collective rearrangement at the onset of flow of a polycrystalline hexagonal columnar phase. 2006. ⟨hal-00120766⟩