Beijing National Laboratory for Molecular Sciences, School of Materials Science and Engineering, College of Chemistry and Molecular Engineering, Academy for Advanced Interdisciplinary Studies, Beijing Science and Engineering Center for Nanocarbons, Peking University, 100871, Beijing, China.
Beijing Graphene Institute (BGI), 100095, Beijing, China.
Nat Commun. 2023 May 25;14(1):3019. doi: 10.1038/s41467-023-38701-4.
Synthetic high-performance fibers present excellent mechanical properties and promising applications in the impact protection field. However, fabricating fibers with high strength and high toughness is challenging due to their intrinsic conflicts. Herein, we report a simultaneous improvement in strength, toughness, and modulus of heterocyclic aramid fibers by 26%, 66%, and 13%, respectively, via polymerizing a small amount (0.05 wt%) of short aminated single-walled carbon nanotubes (SWNTs), achieving a tensile strength of 6.44 ± 0.11 GPa, a toughness of 184.0 ± 11.4 MJ m, and a Young's modulus of 141.7 ± 4.0 GPa. Mechanism analyses reveal that short aminated SWNTs improve the crystallinity and orientation degree by affecting the structures of heterocyclic aramid chains around SWNTs, and in situ polymerization increases the interfacial interaction therein to promote stress transfer and suppress strain localization. These two effects account for the simultaneous improvement in strength and toughness.
合成高性能纤维具有优异的机械性能，在冲击防护领域有广阔的应用前景。然而，由于其内在的矛盾，很难制造出高强度和高韧性的纤维。本文通过聚合少量（0.05wt%）短氨基化单壁碳纳米管（SWNTs），将杂环芳纶纤维的强度、韧性和模量分别提高了 26%、66%和 13%，得到了拉伸强度为 6.44±0.11GPa、韧性为 184.0±11.4MJ m 和杨氏模量为 141.7±4.0GPa 的纤维。机理分析表明，短氨基化 SWNTs 通过影响 SWNTs 周围杂环芳纶链的结构来提高结晶度和取向度，原位聚合增加了界面相互作用，从而促进了应力传递和抑制了应变局部化。这两种效应共同导致了强度和韧性的同时提高。
