Highly Conductive and Lightweight Carbon Nanotube Conductor and Scalable Manufacturing for Conductive Fiberreinforced Composite Application

摘要

Conductive metals such as copper are heavily used as conductors or lightningprotection materials in aircrafts and other industrial areas. But the high bulk densityand corrosion problem make non-metal conductors with low density and corrosionresistancemore promising such as carbon nanotubes (CNTs). However, the smallsample size of previously reported highly conductive CNT fibers (1-2 μm in diameter)or films (less than 1 μm in thickness) limits the practical engineering applications. Inthis work, a macroscopic continuously stretched CNT tape was prepared withexcellent CNT alignment, high conductivity, and large dimensional size (～ 9 mm inwidth and ～ 30 μm in thickness). Through combined post-treatments of mechanicalstretching, iodine doping and polymer capping layer, the macroscopic CNT tapeshows high conductivity in the range of 10,000 S/cm (the highest is ～ 13,000 S/cm)and this excellent performance is stable in open air without any sign of degradation.Various characterizations were conducted including SEM observation, Raman, TGA,PPMS, electrical, and mechanical measurements. Overall, the high conductivity wasascribed to better CNT alignment after stretching and high carrier density after iodinedoping. More importantly, the substantial stability of electrical property wasdemonstrated, benefitting from the polymer capping layer. Additionally, this process isbased on commercially available raw materials and scalable for industrial production.And the proposed method here can be readily transferred to our buckypaper (CNTsheets) with roll-to-roll production capability. Furthermore, these highly conductiveCNT tape and sheet can be directly incorporated into fiber-reinforced composite toimprove the conductivity which could serve multiple functionalities as structural,electromagnetic interference shielding and lightning protection materials in aircrafts.This work opens a new path to optimize the electrical performance of CNT assemblieswith a wide range of engineering applications including conductive composites..