Wet Twisting in Spinning for Rapid and Cost‐Effective Fabrication of Superior Carbon Nanotube Yarns

Abstract Carbon nanotubes (CNTs) are promising blocks for building advanced yarns with unique structural and functional attributes. However, the complexity of fabrication and high cost has hindered the widespread adoption of CNT yarns. In this study, a rapid and continuous twisting wet spun yarn strategy to produce highly densified CNT yarns is presented. The method involves effectively dispersing CNTs in the surfactant dispersion, swiftly removing the surfactant in the coagulation bath and twisting treatment to effectively improve the density of yarn and the orientation of CNT. Detailed characterizations on the influence of each spinning conditions reveal that twisting treatment significantly enhances the packing density of yarns, improves the orientation of CNTs, and mitigates the impact of impurities on conductivity. The resulting CNT yarns exhibit a remarkable tensile strength of 600 MPa, a Young's modulus of ≈40 GPa, and a high conductivity of 8990 S cm⁻¹. When utilized as a yarn heater, the CNT yarn demonstrates an ultra‐fast electrothermal response of over 1000 °C s⁻¹ at a low operating voltage of 5 V. Impressively, the mechanical properties of CNT yarns show good stability during heating. This study provides a perspective of structural engineering for the large‐scale preparation of high‐performance CNT yarns.