Multifunctional PDMS/Fe₃O₄@MMT/SA@PDA-modified melamine sponge for oil/water separation and fire suppression

Abstract

Conventional sorption materials exhibit disadvantages such as low sorption capacity, difficulty in treating heavy oil, and insufficient flame retardancy when addressing oil spills. In this study, a magnetic superhydrophobic photothermal flame-retardant material was synthesized via polymerization and immersion techniques, utilizing cost-effective and environmentally friendly melamine sponge (MS) as the substrate. The modified sponge exhibits a water contact angle of 153°, an sorption capacity ranging from 9.7 g/g to 19.0 g/g for various oils and organic solvents, and stable mechanical properties. It demonstrates excellent oil-water separation performance and reusability. Under light irradiation, its crude oil sorption rate increases by 6.6 times compared to conditions without light exposure. Thermogravimetric analysis (TGA) reveals that the initial decomposition temperature of the modified sponge is 54.7°C higher than that of the unmodified sponge, with a residual mass 2.2 times greater. Moreover, it can efficiently adsorb oil and suppress fire on the water surface under magnetic drive, concentrating the spilled oil within the sponge while leveraging the sponge's inherent flame-retardant property to quickly extinguish the fire.