Centre for Material and Fibre Innovation
ITRI
Nanocomposities are formed by integrating nanomaterials into organic polymers. Properties shown to undergo substantial improvements, in comparison with the base polymer as well as conventional filler counterparts, include:
The most heavily researched type of nanocomposite uses layered mineral clays as the reinforcing phase. (http://www.pslc.ws/macrog/mpm/composit/nano/index.htm) Natural clay 'particles' are sheet-like materials no more than three to five atoms thick.(http://www.rps.psu.edu/0301/clay.html) When dispersed in a polymer, the high surface area of these particles has a big impact on fibre properties. Toyota discovered that the addition of three to five per cent clay to nylon 6 increased the softening temperature from 60°C to 140°C, opening up the possibility of using nylon in timing belts in cars.
An obvious area of application for carbon nanotubes is in nanocomposites, with performance characteristics beyond those of current carbon-fibre composites. (http://www.nanotec.org.uk/report/chapter3.pdf) A limitation to the introduction of carbon nanotubes in composites is the problem of structuring the tangle of nanotubes in a well-ordered manner, so that maximum use can be made of their strength. Another challenge is generating strong bonding between carbon nanotubes and the matrix to give good overall composite performance. Carbon nanotubes have smooth and relatively unreactive surfaces, and so tend to slip through the matrix when it is stressed. One approach explored to prevent this slippage is the attachment of chemical side-groups to carbon nanotubes, effectively to form 'anchors'. Another limitation is the cost of production of carbon nanotubes.
