Europhys. Lett., 61 (2) , pp. 275-281 (2003)
How do closed-compact multi-lamellar droplets form under shear flow? A possible mechanismL. Courbin1, R. Pons1, 2, J. Rouch1 and P. Panizza1
1 Centre de Physique Moléculaire Optique et Hertzienne, UMR 5798 Université Bordeaux I - 351 Cours de la Libération, 33400 Talence, France
2 Departament de Tecnologia de Tensioactius, CID/CSIC Jordi Girona 18-26, 08034 Barcelona, Spain
(Received 5 August 2002; accepted in final form 28 October 2002)
The formation of closed-compact multi-lamellar droplets obtained upon shearing both a lamellar phase and a two-phase-separated lamellar-sponge ( - L3) mixture is investigated as a function of the shear rate , using small-angle light scattering (SALS) and cross-polarized optical microscopy. In both systems the formation of droplets occurs homogeneously in the cell at a well-defined wave vector via a strain-controlled process. These results suggest that the formation of droplets may be monitored in both systems by a buckling instability of the lamellae as predicted from a recent theory.
83.60.Rs - Shear rate-dependent structure (shear thinning and shear thickening).
82.70.-y - Disperse systems; complex fluids.
61.30.Eb - Experimental determinations of smectic, nematic, cholesteric, and other structures.
© EDP Sciences 2003