MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, 38 Zheda Road, Hangzhou 310027, People's Republic of China.
ACS Nano. 2012 Aug 28;6(8):7103-13. doi: 10.1021/nn3021772. Epub 2012 Jul 23.
Liquid crystals of anisotropic colloids are of great significance in the preparation of their ordered macroscopic materials, for example, in the cases of carbon nanotubes and graphene. Here, we report a facile and scalable spinning process to prepare neat "core-shell" structured graphene aerogel fibers and three-dimensional cylinders with aligned pores from the flowing liquid crystalline graphene oxide (GO) gels. The uniform alignment of graphene sheets, inheriting the lamellar orders from GO liquid crystals, offers the porous fibers high specific tensile strength (188 kN m kg(-1)) and the porous cylinders high compression modulus (3.3 MPa). The porous graphene fibers have high specific surface area up to 884 m(2) g(-1) due to their interconnected pores and exhibit fine electrical conductivity (2.6 × 10(3) to 4.9 × 10(3) S m(-1)) in the wide temperature range of 5-300 K. The decreasing conductivity with decreasing temperature illustrates a typical semiconducting behavior, and the 3D interconnected network of 2D graphene sheets determines a dual 2D and 3D hopping conduction mechanism. The strong mechanical strength, high porosity, and fine electrical conductivity enable this novel material of ordered graphene aerogels to be greatly useful in versatile catalysts, supercapacitors, flexible batteries and cells, lightweight conductive fibers, and functional textiles.
各向异性胶体的液晶在制备有序的宏观材料方面具有重要意义，例如在碳纳米管和石墨烯的情况下。在这里，我们报告了一种简便且可扩展的纺丝工艺，用于从流动的液晶氧化石墨烯（GO）凝胶中制备纯“核壳”结构的石墨烯气凝胶纤维和具有定向孔的三维圆柱。石墨烯片的均匀排列，继承了 GO 液晶的层状有序，为多孔纤维提供了高比拉伸强度（188 kN m kg(-1)）和多孔圆柱的高压缩模量（3.3 MPa）。由于其相互连接的孔，多孔石墨烯纤维具有高达 884 m(2) g(-1)的比表面积，并在 5-300 K 的宽温度范围内表现出良好的电导率（2.6×10(3) 到 4.9×10(3) S m(-1)）。随着温度的降低，电导率的降低说明了典型的半导体行为，而二维石墨烯片的 3D 相互连接网络决定了双二维和 3D 跳跃传导机制。这种新型有序石墨烯气凝胶材料具有较强的机械强度、高孔隙率和良好的导电性，可广泛应用于各种催化剂、超级电容器、柔性电池和电池、轻质导电纤维和功能纺织品。
