Selective Interbundle Cross-Linking for Lightweight and Superstrong Carbon Nanotube Yarns

Abstract

In this study, a range of carbon nanotube yarn (CNTY) architectures was examined and controlled by chemical modification to gain a deeper understanding of CNTY load-bearing systems and produce lightweight and superstrong CNTYs. The architecture of CNTY, which has polymer layers surrounding a compact bundle without hampering the original state of the CNTs in the bundle, is a favorable design for further chemical cross-linking and for enhancing the load-transfer efficiency, as confirmed by in situ Raman spectroscopy under a stress load. The resulting CNTY exhibited excellent mechanical performance that exceeded the specific strength of the benchmark, high-performance fibers. This exceptional strength of the CNTY makes it a promising candidate for the cable of a space elevator traveling from the Earth to the International Space Station given its strength of 4.35 GPa/(g cm–3), which can withstand the self-weight of a 440 km cable.

A review of high-performance carbon nanotube-based carbon fibers

“…The formed cross-linkers facilitate load transfer within the CNT fiber, increasing the mechanical strength and modulus, as shown in figure 8. CNT fibers have been coated or infiltrated with various polymers, such as PAN, polydopamine (PDA), polyvinyl alcohol (PVA), polyimide (PI), bismaleimide, resorcinol-formaldehyde resin, and polymeric carboxyl group, to enhance their properties (figure 9) [158][159][160][161][162][163][164][165][166][167][168][169][170][171][172]. The polymers are composited with CNT fibers in various forms, making load transfer between CNTs easier and enhancing shear force.…”

“…Reprinted from [171], © 2019 Elsevier Ltd. All rights reserved. Reprinted with permission from [172]. Copyright (2023) American Chemical Society.…”

Unique correlation between electrical, structural properties and electromagnetic shielding properties of carbon nanotube sheets

“…CNTSs prepared by a direct-spinning method are composed of elongated tubular bundles formed by the aggregation of individual CNTs through van der Waals forces [23]. The one-dimensional structure of these bundles creates an entangled network within the CNTSs [24,25]. In this internal network structure, electrons transfer within the bundles or through inter-bundle junctions, forming an electrical pathway [26].…”

Fabricating Ultrastrong Carbon Nanotube Fibers via a Microwave Welding Interface

“…CNTs in bundles bind together like ropes via van der Waals interactions, which even reach an incredible tensile strength of 80 GPa . Introducing covalent linkages among nanotubes would markedly mitigate intertube slippage . For instance, electron irradiation has been employed on CNT bundles to induce intertube cross-linking, yielding near-ultimate strength (ranging from 35 to 110 GPa) and modulus (ranging from 590 to 1049 GPa) in CNT bundles. − However, the extraordinary attributes exhibited by CNT bundles rarely extend to macroscopic fibers with micrometer-scale diameters …”