高强高模石墨烯纤维的制备研究

Graphene fiber has emerged as a future carbonaceous fiber with high performance and multifunctionalities after conventional carbon fibers. It can be prepared by regularly aligning graphene sheets along the fiber axis. Now, the development of graphene fiber is still being challenged by a fundamental question: how to translate the record mechanical merit of graphene into the mechanical strength of macroscopic fibers in the utmost efficiency. In this project, we proposed a systematic controlling of multilevel and multiscale defects to promote the performance of graphene fibers. We will develop a systematic process ranging from the synthesis of graphene precursors to wet-spinning, structure characterizations and property assessment of fibers. We will track the evolution process of the multilevel defects in the whole preparation and investigate the fundamental relationship between structures and performances. Stretching, finning and densification are employed to minimize defects and upgrade the strength and modulus of graphene fibers. The project establishes a scalable manufacture method for high performance graphene fibers and the deepening understanding on the macroscopic assembly of graphene can be greatly useful for the fabrication of graphene materials with high performance and multifuntionalities.

石墨烯纤维是由单层石墨烯有序排列的新型碳质纤维品种，具有广阔的应用前景和重要的战略意义。单层石墨烯拥有最高的力学强度，然而，如何将石墨烯的力学特性最大程度转化为宏观力学性能是石墨烯纤维发展面临的关键难题。对此，本项目提出“多级多尺度缺陷结构控制”思路来实现石墨烯纤维的高强高模力学性能。项目系统开展石墨烯纤维“原料—制备—结构—力学性能”关系研究，发展“原料调控—纺丝组装过程—后处理”的系统制备方法。系统研究石墨烯制备、组装、后处理过程中缺陷结构以及多级多层次组织的演变过程，细致解析纤维多级缺陷结构，剖析其力学性能与结构的构效关系。通过拉伸取向、细旦化、密实化等方法实现对纤维多级多层次结构的控制，提升纤维拉伸强度、模量及导电导热性能。项目将实现高强度高模量石墨烯纤维的连续可控制备，深化石墨烯纤维结构性能关系的认识，推进石墨烯纤维的结构功能一体化，同时也为其他石墨烯宏观材料的高性能化奠定基础。

项目针对石墨烯纤维的高强度高模量化可控制备及结构性能关系，建立从“原料可控制备”到“纺丝可控组装”以及“低缺陷化后处理”的系统工艺路线，发展塑化拉伸晶化、微纤化等方法有效控制石墨烯纤维“多级多尺度缺陷结构控制”，实现了石墨烯纤维高强度（拉伸强度达3.4GPa）高模量（拉伸模量达340GPa）的性能突破。同时探究石墨烯纤维中多级多尺度缺陷以及组织结构的形成、演变以及与力学性能的构效关系，深化对石墨烯在二维大分子层面的组装行为的认识，为石墨烯纤维发展成结构功能一体化纤维提供基础理论支持，同时也为其他石墨烯宏观材料以及二维宏观材料的高性能化多功能化提供理论指导。以通讯作者发表包括Science Advances、Advanced Materials、Nature Communications、Matter、Accounts of Materials Research等在内的经费标注SCI论文22篇，其中Science Advances 1篇，Nature Communications 4篇，Matter 1 篇，ACS Nano 3篇。申请及授权发明专利3项。