Morphology of Banded Anisotropic Structures

Abstract

The study of the formation of bands of drops along the direction of the vorticity in a concentrated emulsion is presented. That is, the observed anisotropic structures are characterized by regions of high concentration of drops interspaced with regions of about equal width where hardly any particles are present. These particle distributions are a clear departure to what has previously reported for this emulsion. These patterns are induced by the effect of a simple flow in circular parallel plate geometry (CSS450-Linkam), but only after a prolonged time after the inception of the flow. That is, the observation of bands in emulsions only appears after various other phenomena occur in the emulsion. That is, the separation of the flow cell plates is 100 \mu m, and the observation of bands occurs within the interval of shear rates of 3.0 to 5.0 s^{-1}, but only after a long evolution of the initial structure with a series of flows of 0.75 to 2.25 s^{-1}.