"Despite attractive mechanical and electrical properties, CNTs have largely been a disappointment for 'real-world' applications, because it has not been possible to make them in formats that are useful for engineers," explains Peter Antoinette, co-founder and president of Nanocomp Technologies Inc. (Merrimack, N.H.; www.nanocomptech.com), the developer of the process. Short CNTs do not readily form networks within other materials, unless used at very high concentrations.

The Nanocomp process revolves around a proprietary 1-m long heated reactor (photo) that contains a widely available iron catalyst and allows control of 23 separate process variables. Organic alcohols serve as the carbon source for CNTs. "By exerting tight control over the process conditions, we can manipulate the length and dimensions of the CNTs," Antoinette says. The longer, polymer-like CNTs resulting from the process are commercially available as Miralon products, and they can be spun into "yarn" using equipment for textile fiber processing. Because of their length, the Nanocomp CNTs form bundles and networks that allow them to be more useful in macroscale materials, such as for lightweight structural materials.