Synergistic toughening of composite fibres by self-alignment of reduced graphene oxide and carbon nanotubes

The extraordinary properties of graphene and carbon nanotubes motivate the development of methods for their use in producing continuous, strong, tough fibres. Previous work has shown that the toughness of the carbon nanotube-reinforced polymer fibres exceeds that of previously known materials. Here we show that further increased toughness results from combining carbon nanotubes and reduced graphene oxide flakes in solution-spun polymer fibres. The gravimetric toughness approaches 1,000 J g−1, far exceeding spider dragline silk (165 J g−1) and Kevlar (78 J g−1). This toughness enhancement is consistent with the observed formation of an interconnected network of partially aligned reduced graphene oxide flakes and carbon nanotubes during solution spinning, which act to deflect cracks and allow energy-consuming polymer deformation. Toughness is sensitive to the volume ratio of the reduced graphene oxide flakes to the carbon nanotubes in the spinning solution and the degree of graphene oxidation. The hybrid fibres were sewable and weavable, and could be shaped into high-modulus helical springs

Preparation of low density hollow carbon fibers by bi-component gel-spinning method

Sheath–core polyacrylonitrile (PAN)/poly(methyl methacrylate) fibers were spun through bi-component dry-jet gel-spinning method and were used for fabricating hollow carbon fibers. After optimizing stabilization and carbonization conditions, the resulting PAN-based hollow carbon fibers possessed an average strength and modulus of 3.16 and 275 GPa, respectively. Additionally, 1 wt% carbon nanotubes (CNTs) were added to PAN portion to form PAN+CNT sheath. The PAN+CNT-based hollow carbon fiber had an average strength of 3.24 GPa and modulus of 254 GPa. These hollow carbon fibers can be used for fabricating low density and high performance structural composite materials. © 2015, Springer Science+Business Media New York.close0