University of Bristol
A magnet plunged into test tubes filled with soap under an organic solution. The soap on the right is magnetic. You can see how it is attracted to the magnet.
Scientists have created the world's first soap that can be controlled by magnets.
That's right: magnetic suds.
The breakthrough may revolutionize industrial cleaning products and the response to environmental disasters such as oil spills, reports the research team from Bristol University in England.
The soap works like ordinary soap — breaking up the oily, grimy particles it touches and clumping it all into a drop. Only these clumps can be controlled simply by turning on a magnet.
The property could, for example, allow environmental cleanup crews to dump soap onto an oil spill, let it do its thing and then turn on a magnet to remove it all from the environment.
The soap was created by dissolving iron in a range of standard soap materials made of chlorine and bromine ions, similar to those found in mouthwash and fabric softener.
"Any fool would know that if you tried to put a magnet next to a soap bottle, nothing happens," Julian Eastoe, a chemist at Bristol University who led the group that developed the soap, told me Tuesday.
"But what we did is we changed ... an important part of the molecule for a known magnetically active group."
Soap molecules have an oil-loving part and a water-loving part. "It is almost like a schizophrenic molecule," he explained. His team left the oil-loving part alone, but made the water-loving part magnetic.
The addition of iron creates metallic centers within the soap particles that, lab tests show, are big enough be magnetically attractive.
While ionic liquid soaps infused with iron have been suggested as possible, scientists thought the metallic centers would be too isolated for the long-range interactions necessary for magnetic attraction.
A droplet of liquid soap responds to a magnet.
"A single atom alone is not magnetic," Eastoe said. "It is only when put next to neighbors, brothers, that there is a communication between the brothers in a network and that connective communication gives rise to a macroscopic magnetic effect."
Surprised by their lab results, the Bristol University researchers took a sample to the Institut Laue-Langevin in France where they studied it with a so-called neutron microscope.
The neutrons revealed the iron particles were clumping together sufficiently to make the suds magnetic.
According to Eastoe, the potential applications are many.
Simply by turning on or off a magnet, researchers can change the electrical conductivity of the soap, its melting point, and the size and shape of aggregates, for example.
These properties are traditionally controlled with the addition of electrical charge, or changing the pH or temperature of a system. All of these alter the system and can cost money to remediate.
The magnetic property also makes the soap easier to collect and remove from a system once it has done its job. This could prove particularly useful, for example, in cleaning up oil spills.
Research to make the soap commercially viable is ongoing, Eastoe noted.
"We've uncovered a proof of principle," he said, noting that it should open minds to consider other ways to make magnetic soaps. Other solutions might be more attractive, less expensive, or more appropriate for a given application.
But within one to three years, he surmised, "you might see something appear."
More stories on soapy technology:
- That kitchen grease isn't sliding through sewers
- Space washing machine could microwave laundry
- New coating helps wash grease off with water
- Colored bubbles arise after 15-year quest
Findings are reported January 23 in Angewandte Chemie.
As computing power increases exponentially, the ways we relate to computers become more natural — and more ubiquitous. Msnbc.com's Wilson Rothman explores the evolution of interfaces, from primitive punch cards to interactive buildings.