湿法纺制石墨烯纤维：工艺、结构、性能与智能应用

石墨烯纤维是由石墨烯片层通过组装过程形成的宏观一维材料。其具有较好的耐热性、导热性、导电性以及轻质高强等优点，是实现高品质、功能化纤维的重要突破口。石墨烯纤维在超轻导线、可穿戴储能、传感、生物电极等领域具有广阔应用前景。目前，湿法纺制技术是石墨烯纤维的最主要制备手段，与现有的化学纤维制备过程兼容，是最有望实现规模化制备高品质石墨烯纤维的技术。本文首先介绍了湿法纺制石墨烯纤维工艺中的关键步骤，重点讨论了制备技术与石墨烯纤维结构之间的关系。论述了提升纤维性能的相关策略，总结了石墨烯纤维在功能/智能纤维领域应用。并对提升石墨烯纤维性能的关键问题进行总结阐述，展望了石墨烯纤维的发展前景。

Wet Spinning Assembled Graphene Fiber: Processing,Structure, Property,and Smart Applications

Graphene fiber, a macroscopic one-dimensional material formed by assembling elementary graphene flakes, has emerged in response to the increasing demand for multifunctional or even smart fibers. Based on the astonishing properties of graphene building blocks, graphene fiber presents a series of attractive features, such as superior mechanical strength and electronic conductivity, light-weight, and efficient thermal conductivity. As a result, graphene fiber exhibits broad prospects for application in ultralight cables for aerospace, wearable energy storage devices, biosensors, and neuroelectronics. graphene fiber may provide a critical breakthrough for realizing multi-functional fibers or even smart textiles. Since it was first prepared in 2011, numerous fabrication techniques have been developed to assemble graphene fiber, such as wet spinning, space-confined hydrothermal assembly, film twisting approaches, and template-assisted chemical vapor deposition. Among various graphene fiber preparation approaches, wet spinning has great application potential, as it affords the best mechanical strength and electrical conductivity of the prepared graphene fiber, along with great compatibility with the commercialized wet spinning technique. Therefore, the wet spinning approach has attracted extensive attention for batch production of high-performance graphene fiber. Herein, we introduce the pivotal steps of the wet spinning preparation of graphene fiber, with focus on summarizing the detailed strategies for enhancing the fiber properties and we also discuss the relationship between the structure and assembly approaches. The wet spinning technology for assembling graphene fiber includes a series of critical steps, such as preparation of the spinning liquid, bath coagulation, spinneret design, and post-treatment process. These procedures may have a significant influence on the micro-, meso-, and macro-structure of the final prepared graphene fiber. We also discuss the fundamental relationship between the typical properties of graphene fibers and their hierarchical structures, such as the in-planar structure of graphene sheets, aggregation structure of graphene flakes, and the macrostructure or morphology of graphene fiber. The recent advances in graphene fiber-based smart fibers and fabric applications are also analyzed, highlighting possible strategies for promoting structural-functional integrated applications. Finally, the current challenges and possible approaches for further improving the mechanical and electric properties of graphene fiber are presented. This review can be briefly divided into three parts: (1) details of the wet spinning process and its specific influence on the structural features of graphene fiber, (2) characteristics of current graphene fibers and promising strategies for enhancing the properties, (3) latest studies of graphene fiber applications and perspectives for future application.