Study on the Mechanism of Rapid Oil-Water Separation by a Fe₃ O₄ @PMMA@PDMS Intelligent Superhydrophobic...

We prepared an environmentally friendly intelligent Fe₃ O₄ @PMMA@PDMS superhydrophobic oil-absorbing material with simple process and excellent performance, and investigated the effects of different particle sizes of Fe₃ O₄ , different concentrations of PDMS, and different heating times on the superhydrophobicity of the coating. The best performance of the coating was achieved at a particle size combination of 20/500 nm for Fe₃ O₄ , a PDMS to Fe₃ O₄ @PMMA mass ratio of 6 : 1, and a heating time of 2 min at 400 °C. H2-SPSS coating not only has excellent superhydrophobicity, abrasion resistance, self-cleaning property, and chemical corrosion, but also has good flux and efficiency for separating oil-water mixture, with fluxes of 40,540, 32,432, and 37,027 Lm^-2 h^-1 for trichloromethane, dichloromethane and bromoethane, respectively, and separation efficiencies of 99.78 %, 99.74 % and 99.73 %, respectively. In addition, we also prepared a superhydrophobic magnetic polyurethane (SPPU) sponge using Fe₃ O₄ @PMMA@PDMS, which not only has a good oil absorption capacity of 18-44 g/g for different oil substances, it can also move directionally by magnet attraction and absorb oil along a fixed path. Under the control of the magnet, SPPU completes the whole oil absorption process in only 4 s, showing excellent oil absorption and intelligence.