Remote-control soap mixes oil and water on demand

A kind of chemical remote control has been developed by UK chemists who are able to mix and separate oily and watery fluids on demand.

The chemical, which is triggered by light, can also command microscopic nanoparticles suspended in a liquid to neatly separate themselves out for collection.

While mixing together two liquids, or mixing a powder into a liquid, is easy, reversing the process is a vastly trickier proposition.

Chemists regularly wish they could perform such tricks, says Julian Eastoe, a chemist at the University of Bristol in the UK - such as after adding expensive catalytic nanoparticles to an industrial reaction mixture.

"These particles are so small that they are almost impossible to recover," he says. It is only possible using costly processes like heating to high temperatures or ultra-high-speed centrifugation.

Source: newscientist.comAdded: 2 December 2008