Img/2012/4/17/oil-small.jpgWashington: US scientists have innovated a nanosponge that can sweep the seas clean of oil spills and minimise ecological damage to marine life.The airy nanosponges also conduct electricity and can easily be manipulated with magnets.
Nanosponge is a sponge made of pure carbon nanotubes that can absorb up to 100 times its weight in oil. Due to extremely low density, this material has demonstrated a remarkable ability to absorb oil spills from water.
The innovation involves tweaking carbon with a dash of boron while creating nanotubes in a single step making this process possible.
Boron is a chemical element and has some specialised uses, such as in alloy steels and nuclear control. Boron is a chemical element and has some specialised uses, such as in alloy steels and nuclear control.
The team from Rice and Penn State Universities found for the first time that boron puts kinks and elbows into the nanotubes as they grow and promotes the formation of covalent bonds, investing such sponges with robust qualities.
Daniel Hashim, graduate student at the Rice University lab of materials scientist Pulickel Ajayan, said the sponge blocks are both superhydrophobic (they hate water, so they float really well) and oleophilic (they love oil), the journal Nature reports.
Hashim, who led the study, dropped the sponge into a dish of water with used motor oil floating on top. The sponge soaked it up. He then put a match to the material, burned off the oil and returned the sponge to the water to absorb more, according to a Rice statement.
The robust sponge can be used repeatedly and stands up to abuse. Hashim said a sample remained elastic after about 10,000 compressions in the lab. The sponge can also store the oil for later retrieval.
"These samples can be made pretty large and can be easily scaled up," said Hashim, holding a half-inch square block of billions of nanotubes.
"They`re super-low density, so the available volume is large. That`s why the uptake of oil can be so high," said Hashim.
First Published: Tuesday, April 17, 2012, 13:15