Nanoscale http://doi.org/zj6 (2014)

There are a variety of materials for cleaning an oil spill, but many of them can only be operated in situ. In some extreme cases, where polluted waters could harm the safety of workers, there is a need for materials that can be used from a distance. Inspired by marine mussels, Yong Zhao and colleagues have now developed a magnetically responsive film that can efficiently absorb a variety of oils.

The researchers — who are based at various institutes in Beijing — created fibrous poly(vinylidene) fluoride films through electrospinning, and used dopamine (a compound found in the adhesive proteins of mussels) to anchor magnetic iron oxide nanoparticles onto the surface of the fibres. The resulting composite material is magnetically responsive and absorbs oils of different viscosity from water, including soybean oil, diesel and gasoline. Films that contained nanoparticles showed better oil adsorption capacities than the undecorated ones. This is because the nanoparticles increased the surface roughness of the film, which, in turn, increased its ability to repel water and adsorb oils. Films containing oil could be easily separated using a magnet, offering a way to remotely manage oil spills. Moreover, adsorbed oils can be removed from the film by extrusion or centrifugal separation, and the films could be reused without any obvious changes in adsorption capacity over the five cycles examined in the study.