Facile fabrication of magnetic and superoleophilic composite melamine sponges for efficient oil-water separation

s Polyphenol-amine exhibits strong adhesive properties, attributed to its structural similarity to dopamine. In this study, Polyphenol-amine formed from low-cost catechol and diethyltriamine (DETA) as monomers, was blended with hydrophobic agents, including n-dodecyl mercaptan, stearic acid, and ferric oxide, to form soaking agents. Using a facile and environmentally friendly dip-coating method with commercial melamine sponges (MS) as templates, two types of sponges were fabricated: a hydrophobic superoleophilic sponge (PCAD/MS) and a magnetic superhydrophobic superoleophilic sponge (SA/Fe 3 O 4 @PCA/MS). Both modified sponges exhibit exceptional oil absorption capacities, ranging from 74 to 152 g/g and 63–118 g/g for various oils and organic solvents, high oil–water separation efficiency (＞99.1 % and ＞99.5 %), respectively. Additionally, they demonstrate excellent resistance to acidic, alkaline, and saline conditions, remarkable recyclability, and effective demulsification performance. Notably, the magnetic SA/Fe 3 O 4 @PCA/MS could be remotely actuated for continuous oil-water separation, enhancing its potential for large-scale oil spill cleanup and industrial wastewater treatment. Compared with conventional polydopamine- or fluorine-based coatings, this method provides a greener, more economical, and scalable solution for the fabrication of high-performance oil-absorbent materials.