By fabricating a pH-responsive smart device with tunable surface-wetting properties, we have realized continuous in situ separations of oil/water/oil ternary mixtures without ex situ treatments of cleaning or drying. In air, the superhydrophobic/superoleophilic surface of the smart device allowed heavy oil to permeate through while preventing water from passing. When exposed to alkaline water, the superhydrophilicity/underwater superoleophobicity of the smart device surface prevented the passage of hexane while allowing water to penetrate. In this way, efficient separation and collection of the individual components of a complex oil/water/oil mixture was realized in a continuous process with no ex situ treatments. This method could provide a strategy for continuous separations of oil/water/oil ternary mixtures, which are common in practical oil spill cases.
- Guannan Ju
- Mengjiao Cheng
- Feng Shi