Dresden 2009 – wissenschaftliches Programm
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DY: Fachverband Dynamik und Statistische Physik
DY 28: Pattern formation in colloidal and granular systems II
DY 28.7: Vortrag
Freitag, 27. März 2009, 12:00–12:15, HÜL 386
Convection in thermosensitive colloidal suspensions — •Florian Winkel1, Stephan Messlinger1, Wolfgang Schöpf1, Ingo Rehberg1, Miriam Siebenbürger2, and Matthias Ballauff2 — 1Experimentalphysik V, Universität Bayreuth, D-95440 Bayreuth, Germany — 2Physikalische Chemie I, Universität Bayreuth, D-95440 Bayreuth, Germany
We investigate thermal convection in a microgel suspension that consists of core-shell colloids which change their size with temperature. The swelling and shrinking of the particles dramatically modifies the volume fraction and therefore the viscosity of the suspension. As a consequence, a temperature gradient applied to the suspension also induces a gradient of the colloid concentration which strongly influences both the onset and the nonlinear behavior of thermal convection. In our experiment we expose a Hele-Shaw convection cell to a constant temperature difference. The thermal convection is monitored via a shadowgraph setup. We report on the formation and evolution of convection patterns in our microgel suspension.