Boosting fiber properties via selective sorting and wet spinning of high aspect ratio carbon nanotubes

Abstract The development of high-performance fibers using carbon nanotubes (CNTs) has gained significant attention due to their extraordinary mechanical, electrical, and thermal properties. In this study, we focus on the selective sorting and wet spinning of high aspect ratio CNTs to enhance the physical properties of the resulting fibers. By utilizing a lyotropic liquid crystal mesophase, we effectively separated long and short CNTs. At the isotropic cloud point, long CNTs form nematic domains while short CNTs remain in the isotropic phase, enabling selective sorting based on differences in surfactant adsorption probability. After removing amorphous carbon and surfactant molecules through thermal treatment and dialysis purification, continuous CNT fibers were produced via wet spinning process. The CNT fibers, composed primarily of long CNTs, demonstrated outstanding mechanical strength (1.76 GPa) and electrical conductivity (4.17 MS m −1 ), surpassing fibers made from short or as-synthesized CNTs. This strategy provides a promising approach to boost the physical properties of CNT fibers, utilizing commercially available CNTs to broaden their applications in flexible electronics and energy transportation.