Bristol scientists produce magnetic soap that could help clean up oil spills

Scientists at the University of Bristol have dissolved iron in liquid surfactant to create a soap that can be controlled by magnets. The discovery could be used to create cleaning products that can be removed after application and used in the recovery of oil spills at sea.

The soap, composed of iron rich salts dissolved in water, responds to a magnetic field when placed in solution. The soap's magnetic properties were proved with neutrons at the Institut Laue-Langevin to result from tiny iron-rich clumps that sit within the watery solution, a university release said.

The generation of this property in a fully functional soap could calm concerns over the use of soaps in oil-spill clean-ups and revolutionise industrial cleaning products.

Scientists have long been searching for a way to control soaps (or surfactants as they are known in industry) once they are in solution to increase their ability to dissolve oils in water and then remove them from a system.

The team at the University of Bristol has previously worked on soaps sensitive to light, carbon dioxide or changes in pH, temperature or pressure. Their latest breakthrough, reported in Angewandte Chemie, is the world's first soap sensitive to a magnetic field.

Ionic liquid surfactants, composed mostly of water with some transition metal complexes (heavy metals like iron bound to halides such as bromine or chlorine) have been suggested as potentially controllable by magnets for some time, but it had always been assumed that their metallic centres were too isolated within the solution, preventing the long-range interactions required to be magnetically active.