Ultra-Tough and Highly Ordered Macroscopic Fibers Assembly from 2D Functional Metal Oxides Nanosheets Liquid Crystals and Strong Ionic Interlayer Bridging
Macroscopic assembly of 2D nanomaterials, especially for the one-dimensional macroscopic ordered fibers assembly from 2D liquid crystals (LCs), is rising to an unprecedented height and will continue to be an important topic in materials. However, this case of 2D functional metal oxides is quite challenging, everything has to start from scratch. For the first time, the high-performance macroscopic fiber is realized from 2D tungstate nanosheets LCs through a wet-spinning process involving the formation and processability of nematic LCs colloid, macroscopic assembly induced by shear flow and performance enchantment by ionic interlayer bridging. The resultant tungstate macroscopic fibers yield record high tensile strength (198.5 MPa) and fracture toughness (3.0 MJ·m−3) owing to the highly ordered structure and strong interlayer bridging. Despite the intrinsically weak mechanical strength in this kind of metal oxides nanosheets, only a few percent of graphene, the fibers manifest mechanical properties comparable to that of graphene fibers reported previously. Inspired by this concept, the possible LCs colloids and macroscopic fibers of other 2D functional nanosheets will become a reality in the near future, holding great promising in aerospace and wearable applications.