Magnets seen as potential oil-spill cleaner

By Luke Johnson & news reports

26 June 2012 18:34 GMT

As described in the journal Soft Matter, the breakthrough builds on previous research to create a soap-like substance chemically infused with iron particles to make it attractive to magnets.

In the new research, a team of chemists created a type of molecule that can create "magnetic emulsions". The custom-made molecule acts as an "emulsifier", which brings together substances that normally do not mix, such as oil and water, BBC reported.

After adding in the metal particles, the resulting blend can then be collected with a magnet, according to the research.

"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," study co-author Julian Eastoe of the University of Bristol told BBC News.

The technology functions with the use of surfactants, short for "surface-active agents" and the technical name for soap. Surfactants are long chains of atoms. One end of the chain is "hydrophilic", or water-loving, and the other is "hydrophobic", or water-fearing.

In soap, the hydrophobic end attaches to an oily or grimy surface where it breaks down molecules. The soap then pushes the broken down substance to bubble up to the hydrophilic end facing outwards, according to BBC.

The surfactants in the latest study contain metal atoms on the hydrophilic end, which allows the oily droplets to be gathered by a basic magnet.

"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," Eastoe told BBC.

The change allows magnetic molecules to create emulsions when added to even small amounts of surfactants, making it easier to apply the technology to something like an oil-spill clean-up.

Eastoe told BBC that the latest paper demonstrates "a practical application" of magnetic soap "without a shadow of a doubt".