To this aqueous emulsion (5 mL), hexadecane (200 µL, in which some Nile red was also added) and CTAB dispersed in water (5%, 100 µL) were added and the mixture was further sonicated for 30s. This yielded a very turbid, milky solution formed by small droplets surrounded by a red fluorescent shell having a diameter relatively monodisperse lower than 5 µm (figure and). These small droplets no longer coalesced as observed in the oil and CTAB free all-aqueous emulsion. The use of Nile red allowed labelling the oily hexadecane phase and the observation of small circles by epifluorescence (figure ) attested that the shell of these droplets is made of small oil-in-water droplets (stabilized by CTAB) that formed upon sonication of the mixture (note that here, the water phase is in fact a PEG-rich aqueous phase). Obviously, the size of oil-in-water droplets as produced by sonication is expected to range from 100 nm to 1 µm so that these are not distinctly visible on microscopy images. The solution was stable for months and showed creaming but no any coalescence of Dex-rich droplets.