Inorganic Nanotube Mesophases Enable Strong Self-Healing Fibers.

Lee, Won Jun; Paineau, Erwan; Anthony, David Benbow; Gao, Yulin; Leese, Hannah Siobhan; Rouzière, Stéphan; Launois, Pascale; Shaffer, Milo Sebastian Peter · ACS Nano · 2020

basic_science · Level V

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Abstract

The assembly of one-dimensional nanomaterials into macroscopic fibers can improve mechanical as well as multifunctional performance. Double-walled aluminogermanate imogolite nanotubes are geo-inspired analogues of carbon nanotubes, synthesized at low temperature, with complementary properties. Here, continuous imogolite-based fibers are wet-spun within a poly(vinyl alcohol) matrix. The lyotropic liquid crystallinity of the system produces highly aligned fibers with tensile stiffness and strength up to 24.1 GPa (14.1 N tex<sup>-1</sup>) and 0.8 GPa (0.46 N tex<sup>-1</sup>), respectively. Significant enhancements over the pure polymer control are quantitatively attributed to both matrix refinement and direct nanoscale reinforcement, by fitting an analytical model. Most intriguingly, imogolite-based fibers show a high degree of healability <i>via</i> evaporation-induced self-assembly, recovering up to 44% and 19% of the original fiber tensile stiffness and strength, respectively. This recovery at high absolute strength highlights a general strategy for the development of high-performance healable fibers relevant to composite structures and other applications.