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.
Photo by Jeff Fitlow

Nanotubes that can absorb oil, hate water, and be used repeatedly, all while remaining capable of conducting electricity and being manipulated by magnets, show promise for a multitude of oil and gas applications.

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 able to absorb oil spilled in water. The boron puts kinks and elbows into the nanotubes as they grow and promotes the formation of covalent bonds, which give the sponges their robust qualities.

The researchers, who collaborated with peers in labs around the nation and in Spain, Belgium and Japan, revealed their discovery in Nature’s online open-access journal Scientific Reports.

The material, which is created in a single step, is formed into blocks that are both superhydrophobic and oleophilic. The elastic, compressible and and flexible material is more than 99 percent air.

Lead author Daniel Hashim, a graduate student in the Rice laboratory of materials scientist Pulickel Ajayan, demonstrated the carbon nanotube material’s properties through a lab experiment with a dish of water with used motor oil floating on top. [VIDEO: link at bottom of page]

The sponge can also store the oil for later retrieval, he said, or it can be burned off. If burned, the carbon nanotube material remains, allowing to be used to again.