Fig. 5
1D nacre-inspired fibers reinforced by twisting. Morphology of twisted graphene-based fibers: a typical dry-scrolled GO fibers, b quadruple overhand knot, c single knot, d self-coiled homochiral yarn, and e neat two-ply yarn. f Tensile stress–strain curves of fibers synthesized from films with different thicknesses. g Progressive fracture surface of a twisted fiber and h brittle fracture surface of a non-twisted fiber. Reproduced with permission47. i Schematic diagram of the two-step formation of nacre-like composite fibers. j Overall SEM image of twisted PVA-graphene. k Corresponding surface morphology. l Low-magnification and m high-magnification SEM images. n Typical tensile stress–strain curves. o Progressive and p brittle fracture surface. Reproduced with permission48
