Graphene-based fibers synthesized under ambient temperature have not achieved excellent mechanical properties of high toughness or tensile strength compared with those synthesized by hydrothermal strategy or graphitization and annealing treatment. Inspired by the relationship between organic/inorganic hierarchical structure, interfacial interactions, and moderate growth temperature of natural nacre, we fabricate an ultratough graphene fiber via sequential toughening of hydrogen and ionic bonding through a wet-spinning method under ambient temperature. A slight amount of chitosan is introduced to form hydrogen bonding with graphene oxide nanosheets, and the ionic bonding is formed between graphene oxide nanosheets and divalent calcium ions. The optimized sequential toughening of hydrogen and ionic bonding results in an ultratough graphene fiber with toughness of 26.3 MJ/m³ and ultimate tensile strength of 743.6 MPa. Meanwhile, the electrical conductivity of the resultant graphene fiber is as high as 179.0 S/cm. This kind of multifunctional graphene fiber shows promising applications in photovoltaic wires, flexible supercapacitor electrodes, wearable electronic textiles, fiber motors, etc. Furthermore, the strategy of sequential toughening of hydrogen and ionic bonding interactions also offers an avenue for constructing high-performance graphene-based fibers in the near future.

中文翻译：

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通过氢和离子键合依次增韧的超韧生物启发石墨烯纤维

与通过水热策略或石墨化和退火处理合成的那些相比，在环境温度下合成的基于石墨烯的纤维没有获得高韧性或拉伸强度的优异机械性能。受有机/无机层级结构，界面相互作用和天然珍珠母适度生长温度之间关系的启发，我们通过以下方法制备了超韧石墨烯纤维：在环境温度下通过湿纺法依次增强氢和离子键的增韧。引入少量的壳聚糖以与氧化石墨烯纳米片形成氢键，并且在氧化石墨烯纳米片和二价钙离子之间形成离子键。氢和离子键合的最佳顺序增韧产生了具有26.3 MJ / m ^3的韧性和743.6 MPa的极限拉伸强度的超韧石墨烯纤维。同时，所得石墨烯纤维的电导率高达179.0S / cm。这种多功能石墨烯纤维在光伏线，柔性超级电容器电极，可穿戴电子纺织品，纤维电动机等方面显示出广阔的应用前景。此外，氢和离子键相互作用的连续增韧策略也为在不久的将来构建高性能石墨烯基纤维提供了一条途径。