Capillary Bridge of binary immiscible fluids

When a liquid is placed between two rigid bodies, a bridge with minimized surface is formed. The shape of capillary bridges of single liquid between various shapes such as plates, cylinders, and spheres has been investigated theoretically and experimentally. Less attention has been paid to capillary bridges made of two or more mutually immiscible liquids between a pair of solids. This talk will describe our work on using surface evolver simulations to probe the static morphology of capillary bridges made of two immiscible fluids in two geometries: between parallel plates and between a pair of contacting spheres. A phase diagram of configurations for two liquid bridges is obtained upon varying the mutual interfacial tension of the two liquids and the solids, liquid volumes, and geometrical parameters like the inter-plate distance and radii of spheres. We show that capillary bridges between contacting spheres can become non-symmetric when the interfacial energy and volume of the bridge exceeds that of a catenoidal, symmetrical bridge between two spheres.