Polycarbonate, the inexpensive plastic found in compact discs and DVDs, is a remarkable compound with excellent optical and mechanical properties.  However, despite its strengths and ease of manufacturing, it has seen limited use because of one key limitation -- its extremely poor conduction.

Now, Shay Curran, an associate professor of physics at the University of Houston, hopes to change that.  He states, "While its mechanical and optical properties are very good, polycarbonate is a non-conductive plastic. That means its ability to carry an electrical charge is as good as a tree, which is pretty awful.  Imagine that this remarkable plastic can now not only have good optical and mechanical properties, but also good electrical characteristics. By being able to tailor the amount of nanotubes we can add to the composite, we also can change it from the conductivity of silicon to a few orders below that achieved by metals."

Professor Curran hopes to deploy the polycarbonate/carbon nanotube mix in the electronics inside future jet fighters to improve their integrity and protect these highly critical systems against electric pulses or surges.  Furthermore, he says similar coatings could block EMF interference and safeguard personal electronics like phones and computers from thermal/electrical charge buildup.  Thermal and electrical charge buildup is a leading cause of computer failure.

Now that an optimum formulation has been determined, the key to commercializing the tech and helping it to see such exotic deployments will be to turn it into a printable ink.  The ink would be "painted" directly onto airplane electronics and other devices.  Typically, the shielding in airline electronics is made of metal, which is heavier, less elastic, and likely more expensive.

The team also has yielded a breakthrough that may help the rest of the nanotube industry blossom.  The team ditched the typical acid bath that is used to remove soot from the nanotubes and improve their conductivity.  The acid treatment typically damages the tubes and exposes them to defects.  Instead, the team used centrifuging as a means to clean the nanotubes.  The result was a process that took slightly longer, but did less damage to the tubes, yielding greater conductivities.

Professor Corran says that his team is just starting to unlock the polycarbonate/nanotube composites' potential.  He states, "While these are phenomenal results, finding these unusual highly conductive properties has not even begun to scratch the surface.  There is hard science behind it, so developing it further will require significant investment. And we are very thankful to the Air Force for giving us this auspicious start."

His new work is published titled "Electrical Transport Measurements of Highly Conductive Carbon Nanotube/Poly(bisphenol A carbonate) Composite" in the Journal of Applied Physics.