A smart filter with a shape-shifting surface can separate oil and water using gravity alone, an advancement that could be useful in cleaning up environmental oil spills, among other applications. The researchers created a filter coating that repels oil but attracts water, bucking conventional materials' properties
The new coating is a blend of a rubbery, commercially-available polymer and a novel nanoparticle. The polymer can readily form hydrogen bonds with water. The nanoparticle, developed by project collaborators at the Air Force Research Laboratory, is very low in surface energy and does not get wet by oil. The coating creates a smart filter that lets only the water through. The device takes advantage of both gravity and the capillary action phenomenon, enabling liquids to defy gravity in narrow enough spaces.
Also: Learn about a floating oil-spill containment device.
