Preparation of magnetic superhydrophobic melamine sponges for effective oil-water separation

In this work, hydrophobic magnetic nanoparticles (MNPs) were successfully synthesized by the one-pot solvothermal reaction at the presence of surface modifier for the first time and characterized by SEM, EDS, TEM, WAXD, TGA, FTIR, and XPS. The fabrication of the magnetic superhydrophobic melamine sponge was realized by the deposition of the as-synthesized hydrophobic MNPs on the melamine sponge using a simple drop-coating method with the aid of silicone adhesive to achieve a firm attachment. The resultant surface-modified durable melamine sponge exhibited not only the high absorption capacities for different oil and organic solvent ranging from 39.8 g/g to 78.7 g/g but also the good reusability for absorption even after 14 absorbing-squeezing cycles. The oil absorption ability of the magnetic superhydrophobic highly-porous melamine sponge was much better than that of the magnetic superhydrophobic polyurethane sponge with relatively low porosity. Moreover, it could be found from the demonstrating experiments that the as-prepared magnetic superhydrophobic melamine sponge had the abilities to (1) remove the floating peanut oil from water followed by convenient magnetic recovery, (2) separate CH2Cl2 from water as a filter only driven by gravity, (3) absorb and collect peanut oil continuously from water surface assisted by a vacuum pump. We believe that the as-prepared magnetic superhydrophobic melamine sponge should have great potential in the effective oil-water separation.