Nanoscale Interfacial Engineering Lab
Martin F. Haase
Assistant Professor of Chemical Engineering

These four droplets consist mixtures of oil, alcohol and water. Astonishingly, with time the oil and water form multiple shells composed of alternating oil/water layers by phase separation. This happens because the solvent that initially mixes oil and water escapes the droplet to the surrounding water. Pay attention to droplets (c) and (d): At 10 seconds they complete the first phase separation, but this looks clearly different for droplet (c) compared to droplet (d). The reason is: droplet (c) phase separates by nucleation, droplet (d) by spinodal decomposition.