This carbon nanotube sponge created at Rice University can hold more than 100 times its weight in oil. Oil can be squeezed out or burned off, and the sponge reused. (Credit: Jeff Fitlow/Rice University)
Researchers at Rice University and Penn State University have discovered that adding a dash of boron to carbon while creating nanotubes turns them into solid, spongy, reusable blocks that have an astounding ability to absorb oil spilled in water.
The team was the first to to add boron to nanotubes, which puts kinks and elbows into the microscopic material as they grow and also helps covalent bonds to form, giving the sponges their robust qualities.
The researchers say that the nanotube blocks are both superhydrophobic (they hate water, so they float really well) and oleophilic (they love oil). Once soaked in oil, the block can be squeezed and even burned to remove the oil, leaving the block intact and ready for more.
The nanosponges, which are more than 99 percent air, also conduct electricity and can easily be manipulated with magnets.
Nanotube sponges with oil-absorbing potential have been made before, but this is the first time the covalent junctions between nanotubes in such solids have been convincingly demonstrated, say the researchers.
The material could one day have environmental applications. “For oil spills, you would have to make large sheets of these or find a way to weld sheets together," said Pulickel Ajayan, a professor at Rice. Other potential uses include more efficient and lighter batteries, scaffolds for bone-tissue regeneration, and -- with added polymers -- robust and light composites for the automobile and plane industries.
Source: Rice University News & Media