The researchers made a thin film of graphene oxide by chemically exfoliating graphite into graphene flakes, which were then mixed with water and concentrated by centrifugation into a thick slurry. The slurry was then spread by bar coating -- something like a squeegee -- across a large plate. When the slurry dries, it becomes a large-area transparent film that can be carefully lifted off without tearing. The film is then cut into narrow strips and wound on itself with an automatic fiber scroller, resulting in a fiber that can be knotted and stretched without fracturing.
"We found this graphene oxide fiber was very strong, much better than other carbon fibers. We believe that pockets of air inside the fiber keep it from being brittle," says Mauricio Terrones, professor of physics, chemistry and materials science and engineering at Penn State.
esearchers at Penn State and Shinshu University in Japan have developed a simple, scalable method of making graphene oxide (GO) fibers that are strong, stretchable and can be easily scrolled into yarns with strengths approaching that of Kevlar.
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