Enhanced hydrophobicity of shell-ligand-exchanged ZIF-8/melamine foam for excellent oil-water separation

Oil and organic solvent spills have caused serious environmental issues. To address these issues, several novel materials have been developed for the efficient separation of oil/organic solvents from water. In this study, ZIF-8 was loaded onto a melamine foam (MF) skeleton a simple in situ growth method. ZIF-8/MF was modified via a shell-ligand-exchange reaction (SLER) to improve its hydrophobicity. The prepared D-ZIF-8/MF exhibited strong hydrophobicity, with a WCA of 145.1° and an OCA of 0°. D-ZIF-8/MF can absorb up to 68–165 times its weight in oil/organic solvents. D-ZIF-8/MF also exhibited excellent stability, corrosion resistance, recovery, and recyclability. Furthermore, D-ZIF-8/MF has a high oil-water separation efficiency for absorbing organic solvents through a continuous oil-water separation device. This study provides a novel strategy for the preparation of strong hydrophobic foams via surface modification and SLER for oil-water separation. It has immense potential for the scale-up practical treatment of oily wastewater.