Optimization of the purification and processing of carbon nanotubes for strong, conductive and lightweight wires

Single walled carbon nanotubes are produced using standard synthesis and purification techniques. Bulk materials produced using filtration drying are characterized mechanically and electrically for engineering properties. Modifications to the purification process are explored with consideration given for the effects on electrical conductivity and mechanical strength. Raman spectroscopy, thermal oxidation profiling, and high-temperature vacuum annealing are used to gain further insight on the connection between defects and nanotube oxidation during the purification process. It is observed that the mechanical properties are strongly temperature dependent, while electrical conductivity varies with humidity rather than temperature. The use of a thermal vacuum anneal can improve separation of oxidative processes between nanotubes and carbon in the time domain, allowing further optimization of the thermal processing and improved physical properties of nanotube bulk materials post-processing