Researchers tapped into a new method of making graphene that could help finally ramp it up to industrial scale.
Graphene is a "wonder material" made from a single layer of carbon atoms, making it ultra-strong and able to conduct electricity, Penn State Materials Research Institute reported. The material could be used to create flexible electronic displays, more efficient solar cells, stronger wind turbines, and contribute to innovations in high-speed computing.
Researchers have been working to develop methods of producing graphene on the industrial scale in recent years, but this new research reveals a technique that has been overlooked for 150 years.
"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," said Thomas E. Mallouk, Evan Pugh Professor of Chemistry, Physics, and Biochemistry and Molecular Biology at Penn State.
The method, dubbed intercalation, employs guest molecules or ions that are inserted between the carbon layers of graphite to pull the single sheets apart. Intercalation of graphite was first achieved in 1841, but a strong oxidizing agent required in the process reduced the desirable properties of the material. Researcher Nina Kovtyukhov developed the most efficient intercalation method in 1999.
While studying the materials Mallouk asked Kovtyukhov if he could use the method to open up single layers of solid boron nitride, which is a material similar to graphene. The researchers were able to get all of the layers to open. In following control experiments Kovtyukhova left out certain agents and found the damaging oxidizing solution was not necessary in the process. Mollouk wanted to try a the process out on actual graphene, but was reminded of the extensive literature showing oxidation would be required.
"I kept asking [Kovtyukhov] to try it and she kept saying no," Mallouk said. "Finally, we made a bet, and to make it interesting I gave her odds. 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."
The researcher believes this process could be used for a number of layered materials. In the future the researchers hope to figure out a way to speed up the reaction to make it more efficient for industrial use.
The findings were published Sept. 9 in the journal Nature Chemistry.
