▎ 摘　　要

With aid of ultrasonication, water-in-supercritical CO2 (scCO(2)) Pickering-type emulsions were successfully prepared by using graphene oxide as stabilizer. The phenomenon was observed from observation window that after the termination of ultrasonication, the darkness of the emulsion declined rapidly in a short period, and then kept relatively stable for a relatively long duration. The addition of graphene oxide (GO) greatly increases the proportion of dispersed phase (water) in the scCO(2) continuous phase. Under optimized conditions, GO emulsifies up to 23% water in scCO(2) with droplets around 0.5 mu m-3 mu m The stabilization time of these emulsions exceeded 10h and increased with system pressure and GO concentration. The superiority of GO as a Pickering stabilizer was theoretically analyzed in this study: by taking advantage of 2D morphology, GO sheets are more likely to irreversibly attach to the scCO(2)-water interface to form a stabilized emulsion than the conventional 3D particles. (C) 2019 Elsevier B.V. All rights reserved.