Fig. 5: Gas switchable multiphase emulsion mixtures separation and self-cleaning performance.

A Schematic showing the two-step separation process for the multiphase emulsion system under CO₂/N₂ stimulation. B Separation efficiency of PPFM-0.5 with gap width of 150 μm in the 1st and 2nd step operations. The emulsion content is oil content for O/W emulsion and water content for W/O emulsion, respectively. C Photo of the prepared large-size PPFM with 60 × 60 cm. D, E Separation efficiency and flux of the selected area in PPFM with gap width of 150 μm for both W/O and O/W emulsions at 25 °C. The W/O and O/W emulsions used are water/n-hexane and n-hexane/water emulsions, respectively. F Self-cleaning performance of PPFM-0.5 with gap width of 150 μm for both W/O and O/W emulsions with or without organic foulants at 25 °C. The W/O and O/W emulsions used are water/n-hexane and n-hexane/water emulsions, respectively. The concentrations of BSA protein and TC in the O/W emulsion were 1 g/L and 50 mg/L, respectively. G Schematic illustration of the gas-controlled self-cleaning mechanism. The error bars represent the standard deviation and were calculated on the basis of at least three data points measured from different samples.