Preparation of superhydrophobic melamine sponge based on in-situ polymerization for oil-water separation

With the continuous increase in energy demand and the growing severity of environmental issues, oily wastewater has become one of the key sources of pollution. In this study, through the in-situ polymerization reaction of trimethylolpropane trimethacrylate (TMPTMA), acrylic acid (AA), and perfluorooctyl acrylate (PFA), a fluoropolymer (FP) layer was directly constructed on the surface of commercial melamine sponge (MS), successfully preparing the hydrophobic MS@FP sponge. By adjusting the ratio of TMPTMA to PFAc, the content of the fluoropolymer layer on the MS surface can be effectively controlled. This fluoropolymer layer significantly improves the interfacial properties of the sponge and reduces its surface energy, with the static water contact angle of the MS@FP-2 sponge reaching as high as 151°. In addition, the adsorption performance, acid and alkali resistance, and oil-water separation performance of the MS@FP sponge were systematically investigated. The results show that the MS@FP-2 sponge maintains excellent hydrophobicity in strong acid and alkali solutions, demonstrating good chemical stability. The sponge can achieve continuous and efficient separation of chloroform-water mixtures, and the surface fluoropolymer layer is stable, with separation efficiency remaining above 95 % after multiple cycles of separation. The MS@FP-2 sponge, with its outstanding hydrophobic and oleophilic properties, chemical stability, and recyclability, holds broad application prospects in the field of complex industrial wastewater treatment.