Bidirectionally promoting assembly order for ultrastiff and highly thermally conductive graphene fibres.

Li, Peng; Wang, Ziqiu; Qi, Yuxiang; Cai, Gangfeng; Zhao, Yingjie; Ming, Xin; Lin, Zizhen; Ma, Weigang et al. · Nat Commun · 2024

basic_science · Level V

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Abstract

Macroscopic fibres assembled from two-dimensional (2D) nanosheets are new and impressing type of fibre materials besides those from one-dimensional (1D) polymers, such as graphene fibres. However, the preparation and property-enhancing technologies of these fibres follow those from 1D polymers by improving the orientation along the fibre axis, leading to non-optimized microstructures and low integrated performances. Here, we show a concept of bidirectionally promoting the assembly order, making graphene fibres achieve synergistically improved mechanical and thermal properties. Concentric arrangement of graphene oxide sheets in the cross-section and alignment along fibre axis are realized by multiple shear-flow fields, which bidirectionally promotes the sheet-order of graphene sheets in solid fibres, generates densified and crystalline graphitic structures, and produces graphene fibres with ultrahigh modulus (901 GPa) and thermal conductivity (1660 W m<sup>-1</sup> K<sup>-1</sup>). We believe that the concept would enhance both scientific and technological cognition of the assembly process of 2D nanosheets.