cables fabricated using carbon nanotube cores and carbon nanotube tape EMI shielding within a variety of temperature and current density environments were discussed. Nanocomp Technologies has de- veloped a continuous process to produce tens of kilometers of conductive carbon nanotube wire, and insulation process as well as CNT tape EMI shielding. Further the researchers of the company have found that doping CNT wire will have a profound effect on electrical conduction. Techniques to braid or ply CNT fibers to yield wires of many diameters suggest that cables of arbitrary current carrying capacity can be fabricated.
Hybrid copper CNT cables have also demonstrated a specific conductivity better than pure copper at even DC frequencies. They have found at higher frequen- cies that the impedance decreases, unlike copper or aluminum, where the skin effect gives rise to an increase in impedance. This phenomenon makes CNT wire particularly useful where skin effects limit performance. The temperature coefficient of con- ductivity of CNT wires is very small compared with copper or aluminum so at higher temperatures, even up to 150° C (302° F), CNT materials have better performance than aluminum or copper. In addition CNT wires have very high breaking strengths, are resistance to fatigue, and immune from corrosion in chloride environments. http://www.nanocomptech.com
See Interview with Nanocomp‘s CEO in nanotimes 09-13: http://www.nano-times.com/files/nanotimes_09_13.pdf
Philip Dowd, Arizona Technology Enterprises (AzTE), spoke in the session “TechConnect IP Part-
10-07/08 :: July/August 2010
nering: Advanced Materials,” presentation “Na- nofiber Composite Material” about technology inventions at the Arizona State University. AzTE operates as the exclusive intellectual property ma- nagement and technology transfer organization for Arizona State University, USA. Dr. Henry A. Sodano, Professor Mechanical and Aerospace Engineering Department at Arizona State University, USA, has developed a method for enhancing the fiber-matrix interfacial strength. This technique is based on the growth of nanowires (such as ZnO) on structural fibers (such as carbon fiber) under low temperature conditions (<90° C/<194° F). This method has been found to increase the surface area of the carbon fiber by about 1000 times. The carboxyl functional groups in the carbon fiber and a good wetting pro- perty of the epoxy render a stronger chemical bond with ZnO than other compounds. The single fiber tensile test shows that the growth of ZnO nanowires does not affect the in plane properties of the carbon fibers. The single fiber fragmentation test shows that the presence of ZnO nanowires increases the interfacial shear strength by up to 350%. The shear strength can be further increased by controlling the growth of nanowires and by optimizing the pro- perties of the ZnO nanowires. The technique thus produces a fiber reinforced composite with increased strength and toughness without compromising on the in-plane properties.
The technology is available for licensing. http://www.azte.com/page/portfolio
to be continued ...