Polarized optical microscopy reveals beautiful patterns in graphene oxide liquid crystals (scale bar = 100 μm).
Nano-sized flakes of graphene oxide can be spun into graphene fibres several metres long, researchers in China have shown. The strong, flexible fibres, which can be tied in knots or woven into conductive mats, could be the key to deploying graphene in real-world devices such as flexible batteries and solar cells1.
When it comes to physical properties, graphene is remarkably well-rounded. This two-dimensional mesh of carbon atoms has the highest mechanical strength ever recorded, and also breaks records for its thermal and electrical conductivity. But harnessing graphene’s properties requires finding a way to turn these tiny 800-nanometre-wide flakes of carbon into macro-scale materials.
Zhen Xu and Chao Gao at Zhejiang University in Hangzhou, China, have achieved just that. They have used an industrial process called wet spinning to turn an aqueous solution of graphene oxide — a modified form of graphene that is easier to dissolve — into fibres that are tens of metres long. A final chemical reduction treatment turns the long strings of graphene oxide back into graphene.