Europhys. Lett.
Volume 65, Number 2, January 2004
Page(s) 214 - 220
Section Condensed matter: structure, mechanical and thermal properties
Published online 01 January 2004
Europhys. Lett., 65 (2) , pp. 214-220 (2004)
DOI: 10.1209/epl/i2003-10073-7

Hydrodynamic delocalization of phase separation in a locally cooled fluid mixture

T. Araki and H. Tanaka

Institute of Industrial Science, University of Tokyo - Meguro-ku, Tokyo 153-8505, Japan

(Received 11 July 2003; accepted in final form 12 November 2003)

We report that phase separation of a fluid mixture, whose temperature is set below the phase separation temperature only locally near one side wall of the container, is strongly delocalized over the entire system if there is density mismatch between the components. We demonstrate that this delocalization is caused by i) gravity-driven convective flow and ii) asymmetric kinetics between fast hydrodynamic coarsening during demixing and slow diffusional mixing through the phase boundary. The relevant physical parameters determining the efficiency of phase separation are clarified.

64.75.+g - Solubility, segregation, and mixing; phase separation.
47.20.Bp - Buoyancy-driven instability.

© EDP Sciences 2004