Change of morphology of a liquid—liquid dispersion as a stochastic process

Abstract

We report a new phenomenon: that the morphology of an unstabilized liquid—liquid dispersion is predicted by a statistical law rather than by a causal law. For any given volume ratio of the two liquids, only a probability of obtaining one type of dispersion rather than the other can be determined. The inversion point is defined as the volume ratio, all other variables being constant, at which the probabilities of obtaining the two morphological types of dispersion are equal. For a given set of conditions the probability of obtaining a certain morphology, as determined statistically, is a smooth continuous function of the composition, conforming to a symmetrical distribution of probabilities on either side of the inversion point. These effects are demonstrated with a system of three liquid components in which a miscibility gap occurs between two liquid phases. The inversion point manifests a continuous trend toward a 50:50 volume ratio as the two conjugate solutions of the system approach identity of physical properties at their temperature-invariant point. An application of statistical mechanics, in which the degree of mechanical agitation assumes the role of temperature, provides a theory that is confirmed by its agreement with the observed facts.