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Magnetic soap could suck up oil spills

posted 27 Jan 2012, 08:05 by Mpelembe   [ updated 27 Jan 2012, 08:06 ]

Development of the first ever magnetic soap, containing iron atoms, promises to change forever the process of cleaning up oil spills.

GRENOBLE, FRANCE (ILL HANDOUT) - A team of international scientists has invented a magnetic soap that could revolutionise the clean-up of dangerous oil spills. It's the first

cleaning surfactant that responds to magnets.

The team, led by Bristol University Professor of Chemistry Julian Eastoe, created a liquid soap containing iron atoms which help form tiny particles.

It means the surfactant and any materials it dissolves can be removed easily by applying a magnetic field.

Research student Paul Brown demonstrated the soap in the laboratory in Bristol on Wednesday (January 25). "As the magnet comes down toward the magnetic surfactant the soap overcomes both gravity and surface tension and rises up towards the magnet and we can see it coming up through an oily top phase until it is deposited," he explained.

In a separate experiment droplets of magnetic soap were dripped above a metal casing and a 50 pence piece. The magnetic soap moved sideways towards the metal. "An ordinary surfactant would drop just due to gravity but this one has sideways effect due to magnetism," said Brown.

Soap is made of long molecules with ends that behave in different manners. One end of the molecule is attracted to water while the other is repelled by it, as Eastoe explained.

"Like all soaps these molecules are made up of two parts. One of them dislikes water, it's hydrophobic, and is normally an organic part of the molecule. And the other likes water, it's called hydrophilic. What we have in those soaps is a hydrophilic part that contains the element iron, and everybody knows that iron interacts with magnets and so we have synthesises a new kind of molecule which has iron as an integral part of the molecular structure," he said.

With further development, Eastoe believes the soap could find applications in cleaning up oil spills and waste water.

"For today we have uncovered the proof of principle. As I said ten years ago it would have been impossible to have a magnetic soap or surfactant. But now we have them we know how to generate them there are various applications that can be envisaged, the most obvious is the potential for using compounds of this kind in oil remediation or clean-up when there's been an oil spill or an oil slick on the surface of the sea or the ocean," he said.

The detergent action of soap comes from its ability to attach to oily surfaces, with the hydrophobic end breaking up molecules at that surface. The soap molecules then gather up into droplets in which all the hydrophilic ends face outward.

Eastoe and his team started with detergent molecules that he said were similar to what you might find in mouthwash.

The team found a way to simply add iron atoms into the molecules. The droplets that the soap formed were attracted to a magnet, just as iron filings would be.

They sent their samples to the Institute Laue Langevin (ILL) in Grenoble, France, where an intense beam of the sub-atomic particles known as neutrons proved that the iron particles clumped together neatly into iron nanoparticles responding to a magnetic field.

Eastoe said the traditional difficulties faced by environmentalists cleaning sea birds could become a thing of the past.

He said: "Sea birds become contaminated by oil and cleaning them is a great great problem. That is because you cannot suck off the dirt from a sea bird. You can only rely on normal; detergent action. With magnetic soaps it would be possible to have not only the detergency cleaning action but also an added pull of the contaminating oil using an external magnetic field."

The research is still at the laboratory stages but Eastoe said a number of large companies have shown interest in developing the technology.