Dresden 2014 – wissenschaftliches Programm
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DF: Fachverband Dielektrische Festkörper
DF 25: Glasses and Glass Transition II (Joint Session with CPP and DY)
DF 25.7: Vortrag
Donnerstag, 3. April 2014, 17:15–17:30, ZEU 114
Intermittent Quakes on Surface of Soft Glassy Suspensions — •Tadashi Kajiya1, Tetsuharu Narita2, Velonique Schmitt3, Francois Lequeux2, and Laurence Talini2 — 1Max Plank Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany — 2PPMD-SIMM, UMR 7615 CNRS, UPMC, ESPCIParisTech, 10 rue Vauquelin, 75231 Paris Cedex 05, France — 3CRPP, UPR 8641 CNRS, Universite Bordeaux 1, 115 Avenue Schweitzer, 33600 Pessac, France
We present measurements of the thermal fluctuations of the free surface of oil-in-water emulsions which exhibit a glassy behavior. The Surface Fluctuation Specular Reflection (SFSR) technique was applied to measure the free surface fluctuation. SFSR technique permits to probe the height of the fluctuations of liquid surface using the reflection of a laser beam projected on the target surface [1].
We found that when the volume fraction of the oil droplets is close to or larger than the disordered packing volume fraction, the free surface exhibits abnormal fluctuations, consisting of rare but large amplitude quakes. From a statistical analysis of the fluctuation signal, we also found that such large fluctuations become more prominent as the system ages. These quakes correspond to large changes in the local slope of the free surface over a few tenths of a second. We conjecture that such quakes reflect the dynamics peculiar to glassy systems driven by the relaxations of internal stress [2].
[1] A. Tay et al. Rev. Sci. Instrum. 79, 103107 (2008) [2] T. Kajiya et al. Soft Matter. 9, 11129 (2013).