A collaboration between researchers at Penn State University, and Shinshu University in Japan say that they have developed a simple, scalable method of making graphene oxide (GO) fibers that are strong, stretchable, and can be easily crolled into yarn with strengths approximating that of Kevlar.
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, which was spread 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 can then be cut into narrow strips and wound upon itself with an automatic fiber scroller, resulting in a fiber that can be knotted and stretched without fracturing.
The researchers say that they believe that pockets of air inside the fiber keep it from being brittle. This method could open up multiple possibilities for useful products. For instance, removing oxygen from the GO fiber results in a graphene fiber with high electrical conductivity. Adding silver nanorods to the graphene film would increase the conductivity to the same as copper, which could make it a much lighter weight replacement for copper transmission lines.
