Bioinspired superhydrophobic polysulfone foams with micro/nano hierarchical structures for highly efficient solar-assisted cleanup of viscous crude oil

Three-dimensional (3D) superhydrophobic/superoleophilic foams are promising candidates for swiftly and continuously separating immiscible and emulsified oil-water mixtures, but still need further study to fully improve their comprehensive performance, especially for viscous oils. This work designed and prepared superhydrophobic core-shell polydopamine nanoparticles modified polysulfone foams (denoted as SPP foams) with hierarchical micro/nano-structures, which exhibited robust super-wetting property ( B water = 163.1 degrees, B oil = 0 degrees). Immiscible oil-water compounds and water-in-oil emulsions could be continuously separated by the SPP foams with separation efficiencies higher than 99 %. The SPP foams showed high absorption capacity towards different types of oils and organic solvents (between 20 and 30 times of self-weight). The SPP foams also exhibited excellent self-cleaning ability, resistance to strong acids and alkalis, and long-term reusability. Through the integration of polydopamine, the foams achieved prompt photothermal conversion (the surface temperature could be increased to 80.7 degrees C in 1 min under 1 sun), and the generated heat could noticeably decrease the viscosity of crude oil, realizing efficient recovery of vicious crude oil. This study made progress in superhydrophobic/superoleophilic absorbent fabrication and the obtained SPP foams had great potential in treating oil spills especially in the aspect of solar-assisted cleanup of viscous oils.