%0 Journal Article
%A García Fernández, Loreto
%A Bataller, Henri
%A Fruton, Paul
%A Giraudet, Cédric
%A Vailati, Alberto
%A Croccolo, Fabrizio
%T Stabilized convection in a ternary mixture with two Soret coefficients of opposite sign
%D 2022
%@ 1292-8941
%U https://hdl.handle.net/20.500.14352/71648
%X We performed ground-based experiments on the sample polystyrene–toluene–cyclohexane in order to complement the experimental activities in microgravity conditions related to the ESA projects DCMIX4 and Giant Fluctuations. After applying a stabilizing thermal gradient by heating from above a layer of the fluid mixture, we studied over many hours the density variations in the bidimensional horizontal field by means of a Shadowgraph optical setup. The resulting images evidence the appearance of convective instability after a diffusive time associated with the binary molecular solvent consisting of toluene and cyclohexane, confirming the negative sign of the Soret coefficient of this mixture. After a larger diffusive time related to mass diffusion of the polystyrene in the binary solvent, convection was suppressed by the increasing stabilizing density gradient originated by the Soret-induced concentration gradient of the polymer. This is compatible with a positive sign of the Soret coefficient of the polymer in the binary solvent.
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