Emulsions Containing a Third Solid Internal Phase

Abstract

Zero shear-rate rheological properties are calculated for dilute emulsions composed of Newtonian droplets dispersed in a continuous immiscible Newtonian phase and containing a rigid concentric spherical inclusion in the interior of each droplet. A first-order analysis of the deformation of such occluded droplets from the spherical form leads to a qualitative criterion of droplet stability against rupture as a function of shear rate and other basic kinematical and dynamical parameters, especially drop size. In certain circumstances the droplet may be less stable in the presence of the internal solid phase than in its absence. The deliberate introduction of finely divided solid particles (with appropriate surface properties) into a two-phase system may provide a means for creating an emulsion of finer droplet size than would otherwise be possible. Such techniques may also be utilized to enhance interfacial mass transfer area in two-phase contacting devices.