Ultrahigh-ratio drawing during spinning achieves graphene fibres with high strength and thermal conductivity

Graphene and carbon nanotubes are renowned for their exceptional properties, driving research into their application in producing continuous, strong fibers. Recent advancements demonstrate that combining carbon nanotubes with reduced graphene oxide flakes in solution-spun polymer fibers significantly enhances toughness. The resulting fibers achieve a gravimetric toughness of nearly 1,000 J g−1, surpassing materials like spider dragline silk and Kevlar. This improvement is attributed to the formation of an interconnected network of partially aligned reduced graphene oxide flakes and carbon nanotubes during the spinning process, which deflects cracks and facilitates energy-consuming polymer deformation. The toughness is influenced by the volume ratio of reduced graphene oxide flakes to carbon nanotubes and the degree of graphene oxidation. These hybrid fibers are not only sewable and weavable but can also be formed into high-modulus helical springs. By self-aligning carbon nanotubes and reduced graphene oxide flakes within the polymer matrix, the toughness of these composite fibers is further enhanced.