Scalable fabrication of carbon nanotube fibers via quad-channel FCCVD system

Continuous direct spinning via floating catalyst chemical vapor deposition (FCCVD) is a promising route for the mass production of carbon nanotube fibers (CNTFs), yet its widespread application is hindered by the lack of scalable and efficient manufacturing in conventional lab-scale single-reactor system. Herein, we propose a scalable quad‑channel FCCVD system (QC-FCCVD) feathering four parallel reactors, each equipped with an embedded gas-buffering chamber and controlled by a dual independent heating system. Such pilot-scale integrated system enables stable laminar flow and uniform temperature across all reactors, allowing continuous, ten kilometer-scale synthesis of CNTFs at a rate of 2.68 g h-1 with a 50% reduction in specific energy consumption compared to lab-scale single reactor. The as-spun CNTFs exhibit excellent structural uniformity and mechanical integrity, permitting their subsequent intensification and stretching via a continuous multi-channel reinforcement system. The resulting densified CNTFs exhibit superior multifunctional properties: a tensile strength of 4.16±0.04 N tex-1, a modulus of 248.22±20.36 N tex-1, a thermal conductivity of 398.4±44.8 W m-1 K-1, and a specific electrical conductivity of 1510±33 S m2 kg-1. This work establishes a robust, energy-efficient, and scalable pathway for the integrated synthesis and post-treatment of high-performance CNTFs, addressing key challenges for their industrial-scale manufacturing and application.