Graphene, a material that could usher in a new generatin of electrics, could be closer than ever to mass production, thanks to a 10-dollar bet. The substance is created in layers, just one atom thick, yet graphene is 200 times stronger than steel.
Thomas E. Mallouk, a professor from Penn State, made a bet with colleague Nina Kovtyukhova that she could develop a new way of separating sheets of graphene from graphite. The agreed-upon bet was 10-to-one, winning Mallouk 10 dollars, rather than costing him $100.
Graphene, produced in mass quantities, could revolutionize the manufacture of batteries, wind turbines and solar cells. Because the substance is composed entirely of carbon, manufacture could be incredibly inexpensive. Most of the cost has to do with the amount of work required to create the desired form. Diamonds are also made completely from carbon, and can be extremely expensive.
Graphene was first produced by peeling sheets of carbon from graphite using ordinary adhesive tape. This won the Nobel Prize for the developers in 2004. Other methods to produce the material include whipping graphite in a blender, or storing the raw material with dry ice and steel balls. However, the earliest method of production is not economical, and the others produce a product with unacceptably high levels of contaminants.
"There are lots of layered materials similar to graphene with interesting properties, but until now we didn't know how to chemically pull the solids apart to make single sheets without damaging the layers," Mallouk said.
The Penn State researchers discovered the new production technique on an idea that has been around for 150 years.
Intercalation, a process in which ions or molecules are placed between sheets of graphite, was first developed in 1841. However, early techniques of accomplishing this feat involved the use of strong oxidizers or reducers, which negate many of the unique properties of the substance.
Nina Kovtyukhova developed a unique means of achieving intercalation using oxygen in 1999. She soon discovered the process also functioned to open up layers in boron nitride, a substance similar to graphite. Later experiments showed that effect took place, even when the oxidizer was not present.
Mallouk challenged Kovtyukhova to split graphite into sheets of graphene without the use of an oxidizer. Most scientific literature said an oxidizer was required, but the experiment worked.
"If the reaction didn't work I would owe her $100, and if it did she would owe me $10. I have the ten dollar bill on my wall with a nice Post-it note from Nina complimenting my chemical intuition," Mallouk told the press.
Investigation of intercalation as a means of producing graphene was detailed in the journal Nature Chemistry.