Constructing robust and magnetic PU sponges modified with Fe3O4/GO nanohybrids for efficient oil/water separation.

Metal oxides, due to their low cost, environmental friendliness and wide sources, have attracted great attention. We chose iron oxide/graphene oxide (Fe₃O₄/GO) nanohybrids to modify a PU sponge to increase the surface roughness of the sponge without damaging its inherent structural properties. The composite was then treated with octadecane thiol to reduce the surface energy and produce a superhydrophobic and oleophilic absorption material with a water contact angle of 157°. From the absorption experiment with simulated oily water (including diesel oil, lubricating oil, rapeseed oil, chloroform, N,N-dimethyl formamide, tetrahydrofuran, ethanol and acetone), it was found that the Fe₃O₄/GO-modified PU sponge could absorb up to 80–170 times its own weight while showing outstanding recyclability achieved by squeeze/absorption cycles. Moreover, the composite absorption material exhibited weak magnetic properties, suggesting its recycling practicability. These results provide a quick and simple strategy to deal with oil spills and chemical leakage. [ABSTRACT FROM AUTHOR]