CNTs, Criscuolo reported, are among the strongest materials on earth, with a strength about 100 times that of steel at one-sixth the weight, with excellent thermal and electrical conductivity. For the first time in their history, CNTs are now readily available in relatively large quantities from several manufacturers, with the largest being Bayer MaterialScience, Arkema, and Nanocyl.
The primary challenge of CNTs is that they cannot be readily integrated into standard resin and fiber systems. Because CNTs easily agglomerate, they do not mix naturally with water or polymers, and their natural tendancy to clump actually degrades the physical attributes they offer to composite parts. Because of this, companies like Zyvex have been founded to engineer CNT-enhanced resin and fiber systems (mostly epoxies and prepreg carbon fiber) that properly disperse and optimize CNT performance. As a result, said Criscuolo, Zyvex has developed CNT-enhanced prepreg that allows a standard prepreg to offer mechanical benefits approximating an intermediate prepreg.
Criscuolo highlighted several applications that use CNTs today, include baseball bats, skateboards and, more recently, an entire 50-ft/15m-long by 12-ft/3.7m-wide boat called the Piranha. It's an unmanned surface vehicle (USV) that, similar to unmanned aerial vehicles, provides long-range (2,000 miles) surveillance capability on the open ocean. The use of CNT-enhanced prepreg allowed the boat manufacturer to substantially reduce weight, and thus reduce engine size and other mass-sensitive components. Further, the 8,000-lb/3,629-kg boat can accommodate a payload of 15,000 lb/6,304 kg, almost twice its weight.
Look for a more thorough report on CNTs in the January 2010 issue of High-Performance Composites.