Superhydrophobic, conductive and magnetic sponge for high performance oil-water separation and recycled oil absorption

Nowadays, the frequent occurrence of oil spills at sea has caused serious pollution to the ecosystem and has led to a gradual decrease in marine resources. Conventional adsorbent materials have difficulty absorbing high- viscosity oils and separating oil from water, and recycling still has great challenges. We developed a novel superhydrophobic, magnetic, and photo-thermal sponge (SMPS) with a simple preparation method, which is composed of polyurethane (PU) sponge, polydopamine (PDA), acidified carbon nanotubes (ACNTs), ferric tetroxide (Fe3O4), and polydimethylsilane (PDMS), modified by self-polymerization, ultrasonication, and soaking. The modification of ACNTs, Fe3O4, and PDMS further enhances the electrical conductivity, magnetism, photo- thermal effect, and superhydrophobicity of the PU sponge. The SMPS (PU/PDA/ACNTs-Fe3O4/PDMS) can reach a water contact angle of 168.32 degrees, which can still be maintained at 150 degrees in harsh environments, and it has a good oil adsorption capacity (up to 31.06 g/g) and an oil-water separation efficiency of 96 %. In addition, the SMPS has an excellent photo-thermal effect (surface temperature up to 204.9 degrees C) for better adsorption of high- viscosity oils. It can also be used for oil adsorption and recycling in local areas through its own magnetism. This paper has studied PU sponges with superhydrophobic, magnetic, and photo-thermal performance, which provides a new research idea for large-scale, regional cleaning and recycling of marine high-viscosity oil pollution.