Development of coin-shaped ZIF-7 functionalized superhydrophobic polysulfone composite foams for continuous removal of oily contaminants from water

Development of efficient absorbent materials for oil spillage clean-up and environmental pollution remediation is highly desired but remains a challenge. In this work, superhydrophobic/superoleophilic polysulfone based ZIF-7 composite (SPZ) foams were fabricated via chemical modification of polysulfone and integrating with hydrophobic coin-shaped ZIF-7 particles. The synergistic approaches provided the SPZ foams with high porosity, low density and superhydrophobic/superoleophilic features ( θ water =162.3°, θ oil =0°) and outstanding self-cleaning property. The as-prepared SPZ foams exhibited highly selective absorption capacity (up to 3800 wt%) for various kinds of oils and organic solvents. Furthermore, the SPZ foams still maintained 95.2% of its pristine absorption capacity and the θ water remained at 143.6° after ten absorption/distillation cycles. The SPZ foam showed outstanding separation ability towards different types of emulsions with separation efficiency all above 97%. The high oil/water separation efficiency and robust reusability made the SPZ foams promising absorbent in dealing with practical oil spills. • Novel superhydrophobic polysulfone composite foams was successfully fabricated. • Coin-shaped ZIF-7 particles were synthesized and investigated for the first time. • The oil-absorption capability of the foams was systematically investigated. • The foams exhibited excellent oil/water separation performance and recyclability. • The foams could effectively separate different surfactant-stabilized emulsions.