Ultra-stable CO2-in-water foam by generating switchable Janus nanoparticles in-situ

Upon adding only 0.1 wt% NP, ultra-stable CO foam was observed at 60 °C with a bubble coarsening rate 3 orders of magnitude lower than with surfactant alone. Foam bubbles were spherical with NP present, but became polyhedral for the much less stable surfactant-only foams. For this novel like-charged surfactant-NP system, the limited surfactant adsorption on the NP resulted in NP stabilized CO foam, while maintaining NP colloidal stability at high surfactant concentrations and high salinity, providing a new perspective of NP-surfactant design.