Origin of the Slow Dynamics and the Aging of a Soft Glass

Authors :: Luca Cipelletti
Laurence Ramos
Sylvain Mazoyer
Laboratoire des colloïdes, verres et nanomatériaux (LCVN)
Université Montpellier 2 - Sciences et Techniques (UM2)-Centre National de la Recherche Scientifique (CNRS)
Source :: Physical Review Letters, Physical Review Letters, American Physical Society, 2006, 97, pp.238301
Publication Year :: 2006
Publisher :: American Physical Society (APS), 2006.
Abstract: We study by light microscopy a soft glass consisting of a compact arrangement of polydisperse elastic spheres. We show that its slow and non-stationary dynamics results from the unavoidable small fluctuations of temperature, which induce intermittent local mechanical shear in the sample, because of thermal expansion and contraction. Temperature-induced shear provokes both reversible and irreversible rearrangements whose amplitude decreases with time, leading to an exponential slowing down of the dynamics with sample age.<br />Comment: published in PRL 97, 238301, 2006