Reusable nanosponges could soak up oil spills

Posted by Emma Woollacott

Researchers have created a new material that has, they say, an astounding ability to absorb oil spilled in water.

A team at Rice University and Penn State University have discovered that adding a small amount of boron to carbon while creating nanotubes turns them into solid, spongy, reusable blocks.

"Our goal was to find a way to make three-dimensional networks of these carbon nanotubes that would form a macroscale fabric - a spongy block of nanotubes that would be big and thick enough to be used to clean up oil spills and to perform other tasks," says Mauricio Terrones of Penn State.

"We realized that the trick was adding boron - a chemical element next to carbon on the periodic table - because boron helps to trigger the interconnections of the material. To add the boron, we used very high temperatures and we then 'knitted' the substance into the nanotube fabric."

More than 99 percent air, the resulting blocks are superhydrophobic - so they float very well - and oleophilic, loving oil. They even conduct electricity and can easily be manipulated with magnets.

It's possible to use them to soak up oil, remove it by burning or other methods - and then reuse the blocks immediately. In tests, the material has remained elastic after about 10,000 compressions, and it can absorb more than a hundred times its weight in oil.

"Oil-spill remediation and environmental cleanup are just the beginning of how useful these new nanotube materials could be," says Terrones.

"For example, we could use these materials to make more efficient and lighter batteries. We could use them as scaffolds for bone-tissue regeneration. We even could impregnate the nanotube sponge with polymers to fabricate robust and light composites for the automobile and plane industries."