UC San Diego

While many research groups have successfully generated aligned arrays of single- and multi-walled nanotubes, a very limited number of these have been shown to be amenable to drawing into a thread without the use of a polymer matrix. The purpose of this research is to explore and develop enhancements to the structure and arrangement of aligned arrays of carbon nanotubes in order to improve their ability to be drawn into such threads. This is accomplished through investigations into the relationship between synthesis conditions and resulting products. Characterization methods include scanning and transmission electron microscopy, Raman spectroscopy, thermo- gravimetric analyses, atomic-force microscopy, and other techniques. Criteria for drawing are proposed and examined and an in-depth understanding of the chemical-vapor- deposition synthesis of carbon nanotubes is developed. Factors important to the spinnability of nanotube arrays are found to include nanotube diameters, tube stiffness, amorphous carbon deposition, and the catalyst introduction method. Spinnable nanotube arrays are generated and discussed in terms of tube properties, limitations with regard to spinning and the potential for further improvements to the process