Through a novel approach, researchers have created a CNT-based composite material that exhibits significant improvements in fracture performance and structural damping. The researchers use CNTs to influence and increase the 3D composite interlaminar properties, using unique reinforced laminae with carbon-nanotube forests grown on cloth fibers present in adjacent plies. A series of tests showed that the new 3-D nanocomposite material exhibits four times better fracture performance and five-fold increase in their ability to dissipate energy by structural damping in comparison to the original ceramic composites without nanotubes forests. The new nanocomposite material has three times better dimensional stability compared to the base material without CNTs. This could well be the most preferred composite structure for the future structural applications, the researchers say. They applied a major concept called hierarchical manufacturing, in which they start from a nano manufacturing process to build up a structural composite material.
Schematic diagram of the steps involved in the hierarchical nanomanufacturing of a 3D composite. (1) Aligned nanotubes grown on the fibre cloth. (2) Stacking of matrix-infiltrated CNT-grown fibre cloth. (3) 3D nanocomposite plate fabrication by hand lay-up.
The findings of the research group, led by Professor Mehrdad Ghasemi Nejhad, director of the Hawaii Nanotechnology Laboratory at the University of Hawaii, and Professor Pulickel Ajayan at Rensselaer were published in the May 7, 2006 online edition of Nature Materials (“Multifunctional composites using reinforced laminae with carbon-nanotube forests”). Vinod P. Veedu was the lead author
The new 3-D nanocomposite material improves structural mechanical properties by several folds, but at the same time they impart multifunctionality to the same structure. They demonstrated that the novel 3-D nanocomposite performs much better in terms of thermal and electrical conductivities as well.