Nanotechnology: Graphene takes on carbon nanotubes

Carbon nanotubes might have a cheaper, less controversial alternative in graphene, a single-layer flat sheet of carbon atoms that promotes strength and conductivity. Researchers at Northwestern University published their findings in Nature Nanotechnology, reporting that the breakthrough was made possible by isolating the proper kind of graphene sheet. According to a report from the Massachusetts Institute of Technology Review, having a few hydroxyl groups or oxygen atoms loose on the surface of graphene allows the material to link to polymers and disperse evenly. Researchers at Princeton, who coauthored the paper, were able to generate this form of graphene by expanding graphite oxide rapidly at high temperatures.

Rival technology carbon nanotubes are currently under fire after some research showed that they mimic fibrous materials like asbestos, fueling speculation that they also could be carcinogenic. Lab work showed that at letdown ratios of 1%, graphene outperformed or matched the performance of carbon nanotubes in many criteria. Graphene made the polymer 80% stiffer (carbon nanotubes add roughly 50% stiffness), and the graphene composite could withstand 30°C higher temperatures compared with virgin polymer, while carbon nanotubes did not increase temperature stability.

Big 10 rival Michigan State University is undertaking its own work with graphene, with a spinoff company called X G Sciences (East Lansing, MI), which is setting up a pilot plant to create polymer/graphene nanocomposites. Of particular interest are graphene’s strong barrier properties, making it a target for applications in food packaging or fuel systems.—[email protected]