Pyrene-Driven Functionalization Enhances SWCNT Dispersion for High-Performance Fiber Processing

Realizing high-concentration dispersions of single-walled carbon nanotubes (SWCNTs) remains a challenge for efficient fiber spinning. This work shows that functionalization with 4-(N,N-dimethyl-2-aminoethyl)pyrenemethylamine (PyAM) enables such dispersions in chlorosulfonic acid (CSA) by promoting a liquid crystalline phase for fiber spinning. In organic solvents, PyAM-functionalized SWCNTs show a concentration-dependent transition from paper-like to foam-like structures, indicating tunable material properties. In CSA, PyAM-SWCNTs exhibit greatly reduced viscosity compared to pristine SWCNTs, enabling the fabrication of highly aligned fibers through liquid crystal spinning. This directly increases fiber yield per unit time and improves production efficiency, particularly yielding roughly 2.33 times more fiber at 70 mg mL –1 compared to 30 mg mL –1 . The resulting fibers show high mechanical strength (73.48 cN/tex) and enhanced thermal conductivity (200 W/m·K) due to improved dispersion and alignment. Although organic functional groups slightly reduce the specific electrical conductivity (1,050 S·m 2 /kg) due to increased electron scattering, PyAM functionalization provides a scalable approach for optimizing CNT fiber processing. This work establishes a foundation for scalable production of high-performance CNT-based materials that paves the way for their broad application in flexible electronics, energy storage, filtration membranes, and structural composites.