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The European Physical Journal B
ISSN: 1434-6028 (printed version)
ISSN: 1434-6036 (electronic version)
Abstract Volume 4 Issue 1 (1998) pp 65-74
A dynamic study of onion phases under shear flow: size changes
P. Panizza (a), A. Colin, C. Coulon, D. Roux
Centre de Recherche Paul Pascal, avenue Dr Schweitzer, 33600 Pessac, France
Received: 14 November 1997 / Received in final form: 2 March 1998 / Accepted: 9 March 1998
Abstract: It has been shown that lyotropic lamellar phases under shear flow form structures corresponding to a close packed assembly of monodisperse multilamellar vesicles (onions). The size, which is fixed by the shear rate, can vary from a few microns to a tenth of a micron. In this study, we investigate for the first time the transient behaviour of size changes of onions under shear flow by means of small angle light scattering, direct microscopic observations, and conductivity measurements. We evidence two regimes: continuous and discontinuous. The nature of which (continuous or discontinuous) depends on the initial and final shear rate, and can be described by a dynamic phase diagram.
PACS. 83. Rheology - 64.60 Ht Dynamic critical phenomena - 61.30 Eb Experimental determinations of smectic, nematic, cholesteric, and other structures
(a) Present address: Centre de Physique Moléculaire Optique et Hertzienne, Université Bordeaux-I, 351 cours de la Libration, 33405 Talence, France. email: ppanizza@iris.cpmoh.u-bordeaux.fr
Article in PDF-Format (357 KB)
Online publication: July 27, 1998
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