Flexible Co-ZIF-L@melamine sponge with underwater superoleophobicity for water/oil separation

In this study, melamine sponge (MS) is modified by in-situ growth of leaf-like Co-ZIF-L without the addition of additives or surfactants. Such modified MS shows good underwater superoleophobicity because of the unique pore structure and highly rough surface of MS@Co-ZIF-L. Compared to the pristine MS, the water-wetted MS@Co-ZIF-L exhibits excellent water-oil separation for various oils (the separation efficiencies are higher than 99.2%) with good long-term stability (no decrease in flux and separation efficiency after 60 cycles of separation). Moreover, MS@Co-ZIF-L is highly effective to treat oil-water emulsions. Besides the excellent separation performance, due to the outstanding mechanical properties, MS@Co-ZIF-L can be shaped into various configurations such as membranes, filters, adsorbing foams or other forms for the oil/water separation in various situations.