Superhydrophobic, flame-retardant and magnetic polyurethane sponge for oil-water separation

With the increasing environmental pollution by frequent spill accidents and industrial wastewater emissions, superhydrophobic materials for oil-water separation have attracted considerable attention. Herein, we proposed a facile method to prepare superhydrophobic, flame-retardant and magnetic polyurethane sponge (SFRM-PUS) for oil-water separation. Firstly, pristine PUS was immersion-coated with ferric oxide (Fe3O4) nanoparticles, graphene oxide (GO) and phytic acid, and then treated with hydroiodic acid (HI) to reduce GO and modified with perfluorooctyltriethylsilane to provide low surface energy. The SFRM-PUS had a high water contact angle of 156° and a low water sliding angle of 8.9°, and exhibited excellent anti-adhesion property and high oil-water separation efficiency of 98.9%. By means of the magnetic property, the SFRM-PUS was also applied for the removal of oil from water in specified area. In addition, the SFRM-PUS showed superior flame-retardant performance, and the ignited flame extinguished within only 4 s. Our findings conceivably provided a new strategy to prepare functional superhydrophobic materials for the treatment of oil spill accidents and industrial sewage emissions.