Eur. Phys. J. B 4, 65-74 (1998)
https://doi.org/10.1007/s100510050352

A dynamic study of onion phases under shear flow: size changes

Centre de Recherche Paul Pascal, avenue Dr Schweitzer, 33600 Pessac, France

Corresponding author: ^a ppanizza@iris.cpmoh.u-bordeaux.fr

Received: 14 November 1997
Revised: 2 March 1998
Accepted: 9 March 1998
Published online: 15 July 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.