Berlin 2015 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 73: Focus: Disordered Systems/Glasses under Shear (joint session CPP, DY)

CPP 73.3: Talk

Thursday, March 19, 2015, 16:15–16:30, C 243

Transition to flow of binary glasses under applied stress or strain rate — •Marco Laurati¹, Tatjana Sentjabrskaja¹, Jan Hendricks¹, Alan R Jacobs², George Petekidis², and Stefan U Egelhaaf¹ — ¹Condensed Matter Physics Laboratory, Heinrich-Heine University Düsseldorf — ²IESL-FORTH, University of Crete

We investigate and compare the transition to flow of glasses composed by two species of colloidal hard spheres presenting large size asymmetry, upon application of a constant stress or constant shear rate. The transition to flow of the binary glasses is affected by the composition of the mixture, and reflects changes in the prevailing caging mechanism, i.e. transitions between different glass states [1]. Furthermore, the timescales characterising the onset of flow significantly differ depending on the nature of the applied field, i.e. stress or strain. The relaxation of the accumulated stress after removal of the applied field demonstrates the presence of residual stresses that can be tuned through the mixture's composition. The recovery of strain after creep reveals a non monotonic dependence of the recovery time as a function of the previously applied stress, with a maximum recovery time observed in correspondence to the yield stress of the glass. [1] T. Sentjabrskaja et al. (2014), Soft Matter, 10, 6546-6555.