Growth and characterization of carbon nanotubes from novel materials

The discovery of carbon nanotubes has spurred a great deal of research interest due to their exceptional mechanical and electrical properties. Although many applications have been proposed to make use of carbon nanotubes, several major roadblocks prevent their widespread use. The main issue is the lack of a method for the production of large amounts of high-purity carbon nanotubes. Most of the current methods of production either do not produce many nanotubes or produce by-products that must be removed. In order to design a large-scale production method, the growth process must be understood.; The first portion of this work focused on growing carbon nanotubes from different carbon precursors. A high-temperature arc furnace was used to heat carbon black in the plasma. Nanotubes formed from this process did not contain a high percentage of other carbon species traditionally found in arc discharge setups. Since the transformation occurred on the surface of the carbon black, not in the plasma, it was determined that the growth process was a solid-state transformation. Once the growth mechanism was understood, an attempt was made to scale-up the process.; The high-temperature arc furnace was modified to make the nanotube growth process more continuous. An applied magnetic field was able to spread the plasma over larger anodes, as large as four times the original production area. A set of arc parameters that can yield carbon nanotubes for each anode size studied were determined. A two-pronged anode setup has been used to scale-up carbon nanotubes production twofold.; A field emission device was created using carbon nanotubes as field emitters and CdSe quantum dots as phosphor replacements. The carbon nanotube layer is a stable source of field emission without any purification. In addition, cathodoluminescence of CdSe quantum dots is possible with the carbon nanotube layer as the electron source. The cathodoluminescence is only slightly red-shifted compared to its photoluminescence. Different sized quantum dots were able to produce different colors in the device.