'Magnetic emulsions' could clean up oil spills

Researchers have unveiled a molecule that can make "magnetic emulsions", which has the potential to revolutionise the chemical industry.

Emulsions are blends which normally do not mix, like oil and water.

The team's custom-made molecule, described in Soft Matter, acts as an "emulsifier", coating oily materials and acting to blend the liquids.

But because the molecule responds to magnetic fields, it could be put to use in cleaning up oil spills.

The work is an extension of the "magnetic soap" the team reported in January and published in the journal Angewandte Chemie.

The earlier work showed promise for industrial and cleanup applications, but study co-author Julian Eastoe of the University of Bristol said the new paper demonstrates "a practical application without a shadow of a doubt".

The idea of an "emulsion" in paint may be the only familiar use of the word, but emulsions are tremendously common in industrial chemicals and also in many products found under the kitchen sink.

It makes them part of an industry worth billions of pounds.

What is clear from the team's demonstrations is that their magnetic emulsions will be useful in the cleanup of oil spills.

"We're making emulsions from essentially seawater and the kind of oils that would be spilled, and we're seeing that we can manipulate them using a magnetic field," Mr Eastoe told BBC News.

At the heart of both ideas are what are known as surfactants - short for surface-active agents - that are based on metal atoms, which respond to magnetic fields.

These magnetic surfactants are long chains of atoms, with metal atoms at one end.

One end of these surfactant molecules is "hydrophilic", or water-loving, and the other "hydrophobic", or water-fearing.

In a mixture including water and oily substances, the molecules surround bubbles of oils, aligning themselves with their hydrophilic tails pointing outward into the water.

To achieve this effect, Prof Eastoe said the team changed their original formula.

"We've changed the identity of the magnetic component and made it much more active, by replacing what was iron by another iron complex or another complex of gadolinium," he said.

The result is that the magnetic molecules create emulsions even when added in small amounts to currently available surfactants - so they could be easily implemented into industrial or clean-up applications.

Prof Eastoe also says that the simple preparation of the molecules could mean they join a number of other approaches to deliver medicines to specific sites in the body using magnetic fields.