Multifunctional Carbon Nanotube Yarns by Downsizing an Ancient Technology

TLDR

Twisting multiwalled carbon nanotubes during spinning creates torque‑stabilized yarns with strengths exceeding 460 MPa. The yarns deform hysteretically over large strain ranges, reversibly providing up to 48 % energy damping, are nearly as tough as bullet‑proof vest fibers, resist strength loss from overhand knotting, retain strength and flexibility after heating to 450 °C or immersion in liquid nitrogen, and exhibit high creep resistance and electrical conductivity that persist after polymer infiltration, which further boosts strength.

Abstract

By introducing twist during spinning of multiwalled carbon nanotubes from nanotube forests to make multi-ply, torque-stabilized yarns, we achieve yarn strengths greater than 460 megapascals. These yarns deform hysteretically over large strain ranges, reversibly providing up to 48% energy damping, and are nearly as tough as fibers used for bulletproof vests. Unlike ordinary fibers and yarns, these nanotube yarns are not degraded in strength by overhand knotting. They also retain their strength and flexibility after heating in air at 450 degrees C for an hour or when immersed in liquid nitrogen. High creep resistance and high electrical conductivity are observed and are retained after polymer infiltration, which substantially increases yarn strength.