One-step fabrication of superhydrophobic sponge with magnetic controllable and flame-retardancy for oil removing and collecting

Water pollution arising from oil spillage and chemical leakage has emerged as a critical problem imposing threat to the human and animal health. Effective removal of oils and chemical from water has become a global challenge. Recently, superhydrophobic/superoleophilic magnetic controllable (SHPB-SOPI-MC) porous materials have attracted more attention in the field of oil-removing because of the high selectivity, large absorption capacity, easy collection, and ideal recyclability. Moreover, in order to keep safety, the fire proofing performance should be taken into consideration. Therefore, fabricating SHPB-SOPI-MC porous materials with flame-retardancy through a low cost and simple strategy is necessary but also challenging. In this work, an ultrasound-assisted dip-coating method was applied to fabricate polydimethylsiloxane-vermiculite-Fe3O4 (PDMS-VMT-Fe3O4) coating onto discarded polyurethane (d-PU) sponge, which exhibited superhydrophobic, superoleophilic, magnetic controllable, and flame-resistant properties. The PDMS-VMT-Fe3O4@d-PU sponge owned excellent mechanical durability, chemical stability, and long-term storage stability. Importantly, the PDMS-VMT-Fe3O4@d-PU sponge instantly adsorbed oil floating on water under magnetic field driving. Furthermore, PDMS-VMT-Fe3O4@d-PU sponge absorbed various oils and chemical with ideal selectivity, absorption capacity (up to 40 times of its own weight), speed, and recyclability (exceeding 100 cycles). These findings suggested that PDMS-VMT-Fe3O4@d-PU sponge was a promising oil-removing material for practical application of oil spills cleanup.