Coexisting multiphase and interfacial behaviour of ouzo

Speaker's Name: David Sibley
Speaker's Affiliation: Loughborough University
Speaker's Research Theme(s): Applied Mathematics, Fluid mechanics
Abstract: Multi-component liquid mixtures can be both complex and fascinating, with some systems being amenable to simple experimentation at home, giving valuable insight into fundamental aspects of bulk and interfacial phase behaviour. One particularly interesting mixture is thepopular drink ouzo, which has charmed both the general public and scientists by virtue of its ability to display spontaneous emulsification when water is added. When these two clear (and drinkable) liquids are poured into each other, a single milky-coloured liquid is formed. 
In this seminar I will discuss some recent collaborative work finding the equilibrium phase-diagram for the stable liquid phases of ouzo via experiment and modelling and extensions for when the two liquid phases also coexist with a vapour phase (i.e., along a line of triple points) and within our model uncover the complex bulk phase behavior for this simple beverage. As a consequence, this leads to some interesting observations that also apply more widely, about visualising phase diagrams in ternary systems of this type. Our modelling relies on a relatively simple lattice density functional theory model but captures physical reality surprisingly well. We also examine the interfacial behaviour, connecting microscopic density functional theory results with macroscopic (Neumann) predictions for the shape of droplets at interfaces.

Venue: A17