Europhys. Lett.
Volume 75, Number 4, August 2006
Page(s) 624 - 630
Section Interdisciplinary physics and related areas of science and technology
Published online 12 July 2006
Europhys. Lett., 75 (4), pp. 624-630 (2006)
DOI: 10.1209/epl/i2006-10156-y

Yielding of colloidal glasses

K. N. Pham1, G. Petekidis2, 3, D. Vlassopoulos2, 3, S. U. Egelhaaf1, P. N. Pusey1 and W. C. K. Poon1

1  SUPA, School of Physics, University of Edinburgh Mayfield Road, Edinburgh EH9 3JZ, UK
2  Institute of Electronic Structure and Laser-FORTH PO Box 1527, Heraklion 71110, Crete, Greece
3  University of Crete, Department of Materials Science and Technology Heraklion, Crete, Greece

received 10 March 2006; accepted in final form 29 June 2006
published online 12 July 2006

We studied yielding in two kinds of colloidal glasses: hard spheres at high concentrations without and with a short-range interparticle attraction induced by adding non-adsorbing polymer. Our oscillatory shear and step strain measurements reveal single and two-step yielding in these two kinds of glasses, respectively. This finding is interpreted in terms of a simple picture: the breaking of local topological constraints (cages) and the breaking of nearest-neighbour bonds.

82.70.Dd - Colloids.
83.50.-v - Deformation and flow.
83.80.Hj - Suspensions, dispersions, pastes, slurries, colloids.

© EDP Sciences 2006