Particle dynamics in colloidal suspensions above and below the glass-liquid re-entrance transitionA. Latka1, Y. Han2, A. M. Alsayed3, A. B. Schofield4, A. G. Yodh3 and P. Habdas1
1 Department of Physics, Saint Joseph's University - Philadelphia, PA 19131, USA
2 Department of Physics, Hong Kong University of Science and Technology - Hong Kong
3 Department of Physics and Astronomy, University of Pennsylvania - Philadelphia, PA 19104, USA
4 The School of Physics and Astronomy, The University of Edinburgh - Edinburgh, Scotland EH9 3JZ, UK, EU
received 12 February 2009; accepted in final form 6 May 2009; published June 2009
published online 8 June 2009
We study colloidal particle dynamics of a model glass system using confocal and fluorescence microscopy as the sample evolves from a hard-sphere glass to a liquid with attractive interparticle interactions. The transition from hard-sphere glass to attractive liquid is induced by short-range depletion forces. The development of liquid-like structure is indicated by particle dynamics. We identify particles which exhibit substantial motional events and characterize the transition using the properties of these motional events. As samples enter the attractive liquid region, particle speed during these motional events increases by about one order of magnitude, and the particles move more cooperatively. Interestingly, colloidal particles in the attractive liquid phase do not exhibit significantly larger displacements than particles in the hard-sphere glass.
82.70.Dd - Colloids.
64.70.P- - Glass transitions of specific systems.
05.40.Jc - Brownian motion.
© EPLA 2009