Oil spill response technology has been in the public eye ever since the catastrophic explosion onboard the Deepwater Horizon oil rig two years ago, in 2010, which cost 11 workers their lives. Two days later, the BP-operated rig sank and the Macondo wellhead began to haemorrhage crude oil into the Gulf of Mexico at a rate of 5,000 barrels a day. As the world looked on, clean-up experts deployed everything from floating containment booms and dispersants to ROVs and skimmer ships in a desperate effort to stem the flow.
By the time the well was finally capped a full three months later on 19 September, an estimated 4.9 million barrels (780,000 cubic metres) of crude oil had leaked into the Gulf, decimating the region’s fishing and tourism industries and laying waste to fragile marine and wildlife habitats along a 300-mile stretch of the Louisiana coastline. The disaster remains the largest accidental marine oil spill in the history of the petroleum industry.
As the debate over culpability raged on in Washington, 4,000 miles away in the relative calm of Bristol University in the UK, a research team led by Professor Julian Eastoe was starting work on a groundbreaking project which has the potential to revolutionise oil spill clean-up operations.
Eastoe and his team had previously succeeded in developing soaps – or surfactants as they are known in the industry – that were sensitive to light, carbon dioxide or changes in pH, temperature or pressure.
But it is their latest breakthrough, the world’s first soap sensitive to a magnetic field, which has captured the imagination of fellow academics and industry heavyweights around the globe.
"We estimate that the research has been communicated to more than a billion people in the last month," Eastoe told me, from his office at Bristol University’s School of Chemistry.
"When we created these chemicals we became very excited because it was obvious that there were a number of potential applications."
Oil spill solutions: research into magnetic surfactants
Eastoe’s ebullience is both infectious and fully justified. Scientists have long been searching for a way to control soaps once they are in solution in order to increase their ability to dissolve oils in water and then remove them from a system. His discovery could have a range of industrial applications, but the one that has generated most interest is its potential as a detergent that can be safely removed from sensitive environments after application – making it ideal for the recovery of oil spills at sea.
"We all remember the Deepwater Horizon disaster and the sheer volume of oil that was unaccounted for or simply lost," Eastoe said. "No one had a clue what happened to that oil or where it went.
"The most realistic option is that the dispersants used in the clean-up operation transformed the oil into a fine emulsion and those droplets simply drifted off through the ocean.
"Now, imagine if we could magnetise both the oil droplets and the collection booms that sweep across the surface of the ocean – we might be able to track a much larger fraction of that oil than is possible at present."
By dissolving iron particles in water with surfactants containing chlorine and bromine ions, materials commonly found in household products such as mouthwash or fabric cleaner, Eastoe and his team were able to create a metallic centre within the soap particles that could be influenced by a nearby magnetic field.
"A soap is a chemical made from two distinct parts – one part is attracted to water (hydrophilic), the other to oil (hydrophobic)," Eastoe explained. "The magnetic surfactant works like a normal soap by surrounding oil particles and causing them to disperse in water, but with the addition of a magnetic group. So now we can make oil droplets magnetically attractive."
"Another potential use that was suggested by the RSPB is that it might be an additional clean up step for those poor birds that are afflicted by oil spills," he continued.
"One of the problems they find is that they cannot get the oil off the birds without also removing the protective oils that make the birds’ feathers water repellent. So there is a potential for using magnetic soaps as a gentle way of cleaning the birds."
Proof positive: testing the potential of oil-cleaning soap
To test its properties, the team introduced a magnet to a test tube containing the new soap lying beneath a less dense organic solution. When the magnet was introduced, the iron-rich soap overcame both gravity and surface tension between the water and oil to levitate through the organic solvent, towards the source of the magnetic energy, proving its magnetic properties.
Once the surfactant was developed and shown to be magnetic, Professor Eastoe’s team took it to the Institut Laue-Langevin (ILL) in France, the world’s flagship centre for neutron science and home to the world’s most intense neutron source, to investigate the science behind its remarkable property.
When surfactants are added to water they are known to form tiny clumps, known as micelles.
Scientists at ILL used a technique called neutron scattering to confirm that it was this clumping of the iron-rich surfactant that was responsible for its magnetic properties.
Dr Isabelle Grillo, head of the chemistry laboratories at ILL, explained: "The particles of surfactant in solution are too small to see using light but are easily revealed by neutron scattering which we use to investigate the structure and behaviour of all types of materials at the atomic and molecular scale."
Practical magic: industrial applications for magnetic soaps
Magnetic soaps could have a range of industrial applications thanks to their ability to change properties such as electrical conductivity or melting points, with what is essentially a magnetic on / off switch. The challenge now facing Eastoe and his team is how to take an innovation out of the laboratory and into the marketplace in the form of commercially viable products.
"We’ve attracted the interest of companies from very different industries; household care products, engineering, construction, energy and transport and some from the oil and gas and energy industry. The oil and gas companies are big players within the industry, so that gives me great hope that at least one or more of the ideas will come to fruition.
"The surfactants could also be used for water purification," he explained. "One of the big problems in oil rigs is that they are isolated away from the normal supply of water.
"It is difficult to separate the greywater used for dishwashing or washing clothes in order to recover water that is appropriate for flushing toilets in the bathroom, for example.
"So we’re looking at the potential for magnetic soaps to be able to help in that clean-up process when there is very restricted level of water in the local environment."
"Industry discussions are ongoing right now," Eastoe concluded, "and the likelihood is that by the end of the year we will have a good idea about exactly where the technology could hit."