The Methodology of Experimental Investigation of the Kinetic and Aggregative Instability of Macroemulsions

Abstract ABSTRACT A simple, two-parameter methodology has been developed, by which the kinetic unstability of a macroemulsion i.e., sedimentation or creaming, can be separated from the aggregative unstability. It is applicable to systems in which, after cessation of agitation, a clear phase develops, by coalescence of droplets that have been formed under agitation, The methodology has been applied to a series of two-phase systems in which the upper phase was organic and the lower phase, a brine-external mlcroemulsion. The coalescence time parameter, ϕ, was found to be a simple function of the interfacial tension, in the composition range studied, for which γ varied from 0.024 to 0.33 dyne/cm. The sedimentation time parameter, τ was interpreted in terms of a Stokes’ law drift process together with a previously-established relation between drop size and intensity of agitation. The predicted form of the relation between the experimental variables was confirmed.