Press releases
Please quote Nature Materials as the source of these items.
December 2002
Nanotube-reinforced ceramics
Single-wall carbon nanotubes are the toughest fibres known, and structural materials that incorporate nanotubes could have superior properties. Although researchers have developed tough nanotube-reinforced polymer composites, work on ceramic composites has proceeded more slowly. In the January 2003 issue of Nature Materials, Guo-Dong Zhan and colleagues at the University of California report a carbon nanotube/alumina nanocomposite with over twice the toughness of pure nanocrystalline alumina.
To prepare their high-toughness composites, the researchers used a technique called spark-plasma sintering (SPS). Unlike other sintering methods, SPS allows sintering of the nanotube-ceramic powder at relatively low temperatures, which means that the single-wall nanotubes are not damaged during the process. The high quality of the single-wall nanotubes and alumina powder used in the synthesis also contribute to the superior properties of the nanocomposite.
In contrast to previous work on nanotube-ceramic composites, the fracture toughness was found to increase with nanotube density. This is thought to be due to the formation of entangled networks of single-wall carbon nanotubes, which may prevent cracks developing. Further studies of the microstructure and mechanical properties are in progress, but this initial work indicates that entangled ropes of single-wall nanotubes are very promising materials for reinforcing nanostructured ceramic materials.
