Green fabrication of superhydrophobic poly(furfuryl alcohol)-coated melamine sponge

The increasing frequency of organic solvent pollution has raised urgent demands for efficient, sustainable, and recyclable materials for solvent-water separation. In this study, we report a green, facile strategy to fabricate a superhydrophobic melamine sponge (MS) modified with poly(furfuryl alcohol) (PFA) using a zinc-based deep eutectic solvent (DES) system. The DES, composed of choline chloride and ZnCl₂, served dually as both the polymerization medium and catalytic agent for the in-situ polymerization of furfuryl alcohol on the MS skeleton. The resulting PFA-coated MS (PFA/MS) retained its intrinsic porous 3D network while acquiring significantly enhanced surface roughness and hydrophobicity. Water contact angle measurements confirmed superhydrophobicity (167.6°), and the sponge exhibited high selectivity and sorption capacity toward a wide range of organic solvents. This environmentally benign, scalable approach offers a promising platform for the development of reusable sorbents in oil spill cleanup and industrial wastewater treatment.

Keywords:
deep eutectic solvent; green synthesis; poly(furfuryl alcohol); solvent-water separation; superhydrophobic sponge