基于石墨烯量子点/PBO纤维的高性能新型碳纤维研究

Preparation of carbon fiber with nanocomposite fiber is being paid more and more attention now. It is considered to be the most likely way for the super high performance carbon fiber preparation. In this work, we propose a novel method for preparing high performance carbon fiber. The key benefit of this method is the combination of graphene quantum dots (GQDs) with controllable structure and the PBO fiber with the highest strength. GQDs/PBO nanocomposite polymer is firstly synthesized based on the studies of heterogeneous polymerization mechanism between GQDs and PBO polymer. The aggregation structure of GQDs in PBO fiber is controlled in spinning process. And, the orderly structure of GQDs is expected to affect the final carbon fiber structure in the carbonation process. Eventually, a design theory for the new type carbon fiber based on GQDs/PBO composite fiber is proposed. Our experiments are expected to systematically understand the role of GQDs on carbon fiber structure control. Understanding this could be important for understanding the mechanism by which GQDs can efficiently affect the carbon fiber structures and performances. Our researches demonstrate the enormous potential of GQDs for the preparation of super high performance carbon fiber. Furthermore, the advanced performance of GQDs and its application reported here constitute an enabling technology with which material scientist may explore preparation of nanomaterial/polymer composites with controllable structure.

基于纳米复合纤维制备碳纤维已成为当前人们关注的焦点，被认为是碳纤维高强化的发展方向。本项目旨在以石墨烯量子点（GQDs）和目前强度最高的有机纤维PBO为组元，基于高强度GQDs/PBO复合纤维制备新型超高强度碳纤维。研究内容包括：GQDs/PBO非均相聚合规律研究、纺丝过程中GQDs/PBO结构的调控与演变规律、碳化过程中GQDs/PBO结构演化规律及GQDs对碳纤维结构的作用机制、基于GQDs制备的碳纤维结构与性能相关性及设计理论。揭示GQDs对碳纤维结构的模板效应、微结构、结晶度、微晶尺寸、皮芯结构及宏观力学性能的影响机理及其作用规律，探索新型碳纤维多尺度结构控制、结构遗传规律以及增强机制。通过本课题的研究，不但能拓展GQDs的应用领域、丰富量子点/高分子化学这一重要交叉学科的研究内容，更是制备超高性能碳纤维的一次有意义的尝试，是一项前沿创新性的应用基础研究。

本项目通过以石墨烯量子点(GQDs)和目前强度最高的有机纤维为组元，基于高强GQDs基复合有机纤维探索出了新型超高强度碳纤维制备方式。经过4年的研究，本项目采用羧基修饰GQDs接枝改性高性能有机纤维主链结构，明显改善了有机纤维皮芯结构，增强了纤维内部微纤之间相互作用，随着GQDs含量的不断提高，复合纤维的力学性能和耐热性能明显增强，并制备得到不同GQDs含量的高性能复合有机纤维。通过采用稳定、准确的在线和离线的纤维碳化工艺以及结构分析表征方法，实现了GQDs基高性能碳纤维的可控制备，刚性片状GQDs的引入，大幅度提升碳纤维结构规整性、径向结构取向度以及宏观力学性能，结合非均相GQDs聚合规律以及GQDs在碳纤维内部结构遗传规律等基础科学问题的深入探索，较好地完成了预定的研究内容，为制备高性能碳纤维提供了重要的技术支撑。在此基金的资助下，申请发明专利30项，授权发明专利10项，发表学术论文12篇，全部为SCI收录，影响因子大于8的3篇，培养博士生4名，硕士生6名。