Evolution of water-in-oil emulsion controlled by droplet-bulk ion exchange: acoustic, electroacoustic, conductivity and image analysis

The measured electroacoustic signal gradually decays with time. In the final state the mini-emulsion droplets generate practically no electroacoustic signal and appear uncharged. This fact, combined with conductivity measurements, indicates a strong role for electrostatic factors in emulsion stability and its transition to mini-emulsion state. We suggest that ion exchange between the exterior and interior diffuse layers leads to a gradual collapse of the exterior DL and explains all the experimental observations.