Recent advances in the modification of melamine sponge for oil-water separation

Melamine sponge is a major concern for oil-water separation due to its lightweight, high porosity (> 99 %), cost-effectiveness, impressive mechanical properties, and chemical/thermal stability. However, its amphiphilic nature hinders selective oil absorption in water. Recent strategies to enhance hydrophobicity are reviewed, including synthetic methods and materials, with comprehensive explanations of the mechanisms driven by surface energy and roughness. Key performance indicators for MS in oil-water separation, including adsorption capacity, wettability, stability, emulsion separation, reversible wettability switching, flame retardancy, mechanical properties, and recyclability, are thoroughly discussed. In conclusion, this review provides insights into the future potential and direction of functional melamine sponges in oil-water separation.