Preparation of amphiphilic Janus particles and their application in stabilising foams

This work presents the preparation of foaming Janus particles (JPs) decorated with fluorinated chains by the Pickering emulsion method and investigates their self-assembly behaviour at the air-water interface and foam stability under a limited range of concentrations. When the particle concentration reached 0.6 wt%, the adsorption of the JPs at the interface was saturated and the equilibrium surface tension dropped to around 38 mN/m even after an increase in the particle concentration. When the particle concentration reached 0.4 wt%, the Gibbs stability criterion was fulfilled. During the observation period, the foam volume was maintained relatively constant and the bubble size exhibited no significant changes. Additionally, the liquid fraction of the foam exhibited static equilibrium at different observed concentrations, which demonstrated effective drainage arrest. Overall, the present work validated the efficiency of the fluorinated JPs in stabilising the foams.