Design of Recyclable Superhydrophobic PU@Fe3O4@PS Sponge for Removing Oily Contaminants from Water

With the increase of oil spill accidents and discharge of oily wastewater, a novel oil adsorption material with superhydrophobicity and reusability is desired. To our knowledge, low surface energy and surface roughness are two key factors for superhydrophobic materials. Thus, a recyclable superhydrophobic PU@Fe3O4@PS sponge was fabricated through ultrasonic dip-coating and self-initiated photografting and photopolymerization (SIPGP) to attach Fe3O4 nanoparticles and polystyrene (PS) brushes onto the skeleton surface of the polyurethane (PU) sponge, constructing superhydrophobic micronano hierarchical surface. The preparation process was facile and simple, which was accomplished without initiator under simple UV irradiation. This as-prepared sponge selectively removed various oily contaminants from water with high adsorption capacity, and its magnetic property and elasticity endowed it with good reusability. When it was connected with a negative pressure system, continuous oil–water separation was achieved...