Carbon Nanotube Fiber Doping

Carbon nanotubes (CNTs) have been at the frontier of nanotechnology research for the past two decades. The interest in CNTs is due to their unique physical and chemical properties, which surpass those of most other materials. To put CNTs into macroscale applications, the nanotubes can be spun to form continuous fiber materials. Thus far, the properties of the fibers are far below the properties of the individual nanotubes. If the electrical and mechanical properties of the fibers could be improved, the resulting superfiber materials would change the industry and society. For example, CNT materials might replace copper wires providing lighter, stronger cables for aerospace applications. The small size of individual nanotubes, and the mixture of different diameters and chiralities, limits the electrical conductivity of CNT fiber. A simple way to improve the electrical conductivity of CNT fibers is chemically doping the CNTs within the fibers. This chapter attempts to summarize, classify and provide a basic understanding of doping at the atomic and molecular levels. Characterization of doping and current results of our doping efforts are discussed.