Macroscopic neat single-wall carbon nanotube fibers

Abstract

Measured and predicted properties of individual single wall carbon nanotubes (SWNT) suggest that bulk SWNT materials will exhibit a variety of exceptional properties. Due to the anisotropic nature of SWNTs, fibers are a logical candidate for these objects. The first ever macroscopic fibers, consisting entirely of SWNTs, were successfully produced and characterized. Nanotubes were dissolved at high concentrations (6--10 wt%) in 102% sulfuric acid. The SWNT/sulfuric acid system exhibited unique one-dimensional liquid crystalline phase behavior and interesting rheological characteristics. Fibers were extruded using a wet jet solution-spinning approach into diethyl ether without extensional drawing. Structural analysis showed them to be the highest aligned neat SWNT material produced to-date, with a revealing substructure of coagulated liquid crystalline domains. Additional characterization showed useful electrical and thermal properties and promising mechanical properties. Finally, the Spinning Bob Mixer (SBM), a custom laboratory mixer/extruder, was designed and successfully tested. Various features of the apparatus were demonstrated and shown to be valuable experimental tools for understanding the production of near SWNT fibers. This research has begun the exploration of an interesting and new field of nanotube science by providing a foundation of understanding and enabling future experiments.