Hot-Drawing of Single and Multiwall Carbon Nanotube Fibers for High Toughness and Alignment

• Published in: Nano letters 2005-11, Vol.5 (11), p.2212-2215
• Main Authors: Miaudet, P, Badaire, S, Maugey, M, Derré, A, Pichot, V, Launois, P, Poulin, P, Zakri, C
• Format: Article
• Language: English
• Subjects: Applied sciences; Condensed Matter; Condensed matter: structure, mechanical and thermal properties; Electronics; Exact sciences and technology; Materials Science; Microelectronic fabrication (materials and surfaces technology); Nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Structure of solids and liquids; crystallography
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl051419w

We report a new hot-drawing process for treating wet-spun composite fibers made of single- and multiwall carbon nanotubes and poly(vinyl alcohol). As shown in previous reports, untreated composite nanotube fibers exhibit a very large strain-to-failure, and their toughness, which is the energy needed to break the fibers, exceeds that of any other known materials. However, untreated composite nanotube fibers absorb a very small amount of energy at low strain and become degraded in humid conditions. In this work, we use hot-drawing treatments, a concept inspired from textile technologies, to improve the properties of nanotube/PVA fibers. This treatment yields a crystallinity increase of the PVA and an unprecedented degree of alignment of the nanotubes. These structural modifications lead to a markedly improved energy absorption at low strain and make the fibers resistant to moisture. Hot-drawn nanotube/PVA fibers hold great potential for a number of applications such as bulletproof vests, protective textiles, helmets, and so forth.