Graphene makes rockets go faster

A material known as graphene, which consists of a single layer of carbon atoms arranged in a chicken-wire pattern, can be manufactured to include ruptures studded with oxygen atoms (red balls). The resulting “functionalized graphene sheets” have been found to make rocket fuel burn faster. (Image courtesy of Annabella Selloni and Roberto Car)

A material known as graphene, which consists of a single layer of carbon atoms arranged in a chicken-wire pattern, can be manufactured to include ruptures studded with oxygen atoms (red balls). The resulting “functionalized graphene sheets” have been found to make rocket fuel burn faster. (Image courtesy of Annabella Selloni and Roberto Car)By Catherine Zandonella

Graphene, the single atom-thick carbon sheet that has garnered attention for its novel electronic properties, can also act as a catalyst in fuels to propel the super-speedy rockets of the future. Researchers at Princeton and Pennsylvania State University collaborated to explore the use of graphene additives to speed up the burn rate of nitromethane, a liquid fuel.

The researchers found that they could speed the combustion rate by about 175 times with the addition of functionalized graphene sheets, which are nearly identical to pristine graphene but have lattice vacancies and oxygen groups sprinkled throughout the layer. “You can think of graphene as a sheet of chicken wire,” said Ilhan Aksay, a key collaborator on the research and a professor of chemical and biological engineering at Princeton. “Functionalized graphene sheets are like chicken wire with ruptures or vacancies in the lattice. These vacancies can contain oxygen groups.”

The vacancies, Aksay said, greatly accelerate the combustion of nitromethane through the exchange of protons or oxygen atoms between the oxygen-containing groups and the fuel. The team made the discovery using computer models that simulate the interactions of atoms, and published the results in the Journal of the American Chemical Society. The first author on the study was Li-Min Liu, a former Princeton postdoctoral researcher now at the Beijing Computational Research Center. The research team included Penn State professor of mechanical engineering Richard Yetter and Princeton researchers Roberto Car, the Ralph W. *31 Dornte Professor in Chemistry; Annabella Selloni, the David B. Jones Professor of Chemistry; and Daniel Dabbs, a research scientist in chemical and biological engineering. The project was funded by the American Recovery and Reinvestment Act (ARRA) through the U.S. Air Force Office of Scientific Research.

-By Catherine Zandonella