A new commercial manufacturing process for carbon nanotubes (CNTs) produces tubes in the range of 1–10 mm in length (5–12-nm dia.), two orders of magnitude longer than currently available CNTs, which typically have lengths from 5–20µm.
“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.
Nanocomp Technologies has been covered many times at Nextbigfuture they have their Miralon sheet and tape products which are pure carbon nanotube (CNT) non-woven materials that can be used in a variety of applications to lightweight and enhance product or system performance. They are manufactured via chemical vapor deposition into the final product format, eliminating the need for binders or secondary processing steps. They are composed of bundled CNTs hundreds of microns thick and millimeters long. Miralon sheet and tape formats have successfully been used in aerospace, electrical, and structural applications.
Nanocomp CNTs can also be made into strong polymer-like sheets that can be used in firearm-protection armor. The U.S. Dept. of Defense recently awarded the company $18.5 million to supply soldier and law enforcement body armor. The sheets can also be used as area heaters, Antoinette says, because they emit infrared radiation when low-energy power is applied.
Nanocomp currently produces its CNTs at a scale of 2 tons/yr and plans to triple its manufacturing capacity in 2017. Eventually, capacity could reach 20 tons/yr, Antoinette says, adding that the rapid growth has been helped greatly by support for nanotechnology manufacturing from the state of New Hampshire.
Strong, lightweight, flexible
Good in-plane thermal conductivity, low thru-plane thermal conductivity
Chemically and environmentally resistant
Near zero coefficient of thermal expansion, similar to graphite and carbon fiber
Honeycomb core structures
Far infrared heating solutions
EMI and ESD protection
Wire and cable shielding
Environmental protection (corrosion and UV resistance, thermal shielding, etc.)