Novel magnetic and flame-retardant superhydrophobic sponge for solar-assisted high-viscosity oil/water separation

The development of new multifunctional adsorbent sponge with superhydrophobic, magnetic drive, flame retardancy and efficient adsorption of high viscosity oils display an attractive potential for oil/water separation. In this work, the Fe3O4 nanoparticles with photothermal and magnetic effect were used to achieve solar-assisted efficient adsorption of high-viscosity oil and controlled magnetic drive adsorption and recovery. Using intrinsic flame-retardant melamine-formaldehyde (MF) sponge as the skeleton, the Fe3O4 nanoparticles and poly-dimethylsiloxane solution (Fe3O4/PDMS) were used to modify superhydrophilic sponges into superhydrophobic (WCA = 158 degrees) and superoleophilic (OCA = 0 degrees) sponges with excellent flame-retardant property. Due to the chemical stability, low density and high porosity, the modified sponge exhibits excellent oil and organic solvent adsorption properties and reusability. Owing to the excellent photothermal performance of Fe3O4/PDMS modified MF (Fe3O4/PDMS@MF) sponge, the sponge was heated rapidly with solar-assisted and decreased the viscosity of the high-viscosity oil, which allowed the high-viscosity oil to be absorbed efficiently. At the same time, the Fe3O4/PDMS@MF sponge can be controlled by the remote magnetic field and enters the special oil pollution area for oil adsorption and recovery. This superhydrophobic multifunctional sponge has great potential for high-viscosity oil adsorption, magnetic drive recovery and flame-retardant applications.