Stabilizing Liquid Drops in Nonequilibrium Shapes by the Interfacial Jamming of Nanoparticles

Abstract

Dynamic Surfactants Surfactants are used to form a stable interface between two nonmiscible liquids, like oil and water, so that droplets of one fluid can be entrained in the other. Cui et al. (p. 460 ) designed a surfactant based on the association of a hydrophilic nanoparticle with a functionalized oleophilic molecule that self-assembles at a water-oil interface to produce a composite surfactant. Once adsorbed, the nanoparticles tend to remain in place causing them to accumulate and “jam” at the interface. When a drop was deformed, more surfactant could assemble at the surface, allowing droplets of various shapes to be produced.