Magnetic Sponge Developed for Oil Spill Cleanup

Nashaat Nassar, an associate professor at the Schulich School of Engineering, has developed a material that acts as a super sponge for spilled oil. Photo by Michael Platt, University of Calgary

A team of researchers at the University of Calgary in Canada have developed a sponge for soaking up aquatic oil spills that is composed of magnetic boron nitride.

The non-toxic, biodegradable material, consisting of magnetic nanostructured white graphene, absorbs crude oil at up to 53 times its own weight. It can also be reused, and unlike some clean-up technologies, it allows for recovery of spilled oil.

Led by Dr. Nashaat Nassar, the team conducted tests demonstrated that, placed in water where an oil spill has taken place, the hydrophobic material repels water while attracting the oil, at which point the magnetic boron nitride surrounds and absorbs it. Once the oil has been soaked up, magnets are lowered close to the surface of the water, lifting the magnetic sponge and oil together, where it can be separated and the sponge reused.

While magnetic nanomaterials have been considered before for oil spill cleanup, biopersistence – that is, a material tending to remain inside a biological host – made the prospect too dangerous, due to the risk of disease like lung cancer and genetic damage to the lung. However, Nassar's material has been shown to be biocompatible with humans and other organisms.

Nassar says the new nanomaterial is ready for real-life applications. “If someone wants to start manufacturing this, it is ready to be used right now.”

The Deepwater Horizon explosion that led to 4.9 million barrels of oil to spill in the Gulf of Mexico in 2010 has prompted scientists to rethink cleanup technologies, and another recent development made by scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory in 2017 is called Oleo Sponge. The material easily absorbs oil from water, is reusable and can pull dispersed oil from the entire water column. The scientists started out with common polyurethane foam and then infused hard metal oxide atoms within complicated nanostructures. This serves as glue for attaching other oil-attaching molecules. The material, which looks a bit like an outdoor seat cushion, can be wrung out to be reused and the oil recovered.

Last year, researchers from Flinders University in Australia, developed an absorbent polymer made from waste cooking oil and sulfur (a by-product of the petroleum industry). The highly buoyant polymer acts like a sponge to absorb oil from sea water, and it can be squeezed to recover the oil and then reused.