Researchers discover ‘super material’ in coal
Researchers at Virginia Tech have found a way to use coal to create a “super material” known as graphene.
Graphene has the highest thermo-conductivity of any known substance on the planet. It can take heat away from chips in our computers. And it’s used in batteries for electric vehicles.
It’s very flexible and strong, and could be used to build spacecraft. “It’s 250 times stronger than steel,” said Roop Mahajan, a Professor of Mechanical Engineering at Virginia Tech.
Graphene was discovered in 2004. Since then, scientists have been trying to figure out how to make it using substances other than graphite, which is in short supply, and difficult to mine.
“Most of it comes from China,” Mahajan said.
So he and his team of researchers at Virginia Tech discovered a way to use coal to make graphene.
Their lab sources coal from a mine in Pennsylvania. They pour small coal rocks into a small machine that shakes it into a powder. Then another machine strips away all the silica and other materials, purifying it with acid.
Eventually, they convert the powder into particles so thin, they’re considered two dimensional, 100 times skinnier than a strand of hair. You can’t see them unless you put them under a microscope.
“Graphene is one of the next wonder materials of the century. It can go into almost any field,” Sprow said. Cyrus Sprow is a master’s student at Virginia Tech, studying in the lab.
Sumam Jhajharia is a post-doctorate researcher who also works in this lab.
For her PhD, which she did in India, she made graphene using traditional methods. From graphite. Which is dangerous. It’s potentially explosive, and requires handling a lot of acidic chemicals.
“So once I came to this group, we started making it from coal. Since that, the use of acid has come down, the processing begin a lot easier,” Jhajharia said. This process using coal feels safer, she said.
This process is also cheaper than traditional methods of creating graphene particles, and it requires fewer chemicals. Still, the process does use one acid, and the research is still being studied.
Mahajan said the market for graphene is expected to grow sharply over the next few years. However, it won’t come near requiring the amount of coal currently used to produce electricity.