Coexistence of liquid-like emulsion and solid-like emulsion glass beyond the close-packing limit

The unjamming-jamming transition of a concentrated oil-in-water emulsion is generally characterized by a critical volume fraction of the dispersed phase. However, in this work, we demonstrate that both liquid-like emulsions and solid-like glasses can coexist in a certain range of volume fraction. At a given volume fraction, jammed glasses can be obtained from their emulsions directly by applying mechanical agitation. This agitation-induced ergodic-nonergodic transition is attributed to the reduction of the droplet size. The decrease of the droplet size leads to a significant growth of lubrication repulsions between neighboring particles. This coexistent behavior indicates that size does matter in concentrated dispersions of soft particles. An application example showed that the elasticity of solid-like glass can give the medium supporting ability while the liquid-like emulsion cannot.(c) 2020 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.