Combining Nanomaterials for Improved Performance

A few years ago there were several news stories and research articles indicating the advantages of graphene over carbon nanotubes. I find it interesting that recently research articles have been talking about obtaining better performance when graphene and carbon nanotubes are used together. That combination, in some situations, can result in better performance than when using either of them separately.

For example, a few years ago researchers at Rensselaer Polytechnic Institute found that when they used graphene to reinforce a polymer rather than carbon nanotubes, a higher strength composite was formed. It appears that the flat graphene was better at bonding with the polymer than the cylindrical nanotubes. However, these same researchers have recently found that a combination of graphene and carbon nanotubes in the polymer results in an even stronger composite. This result is due to the fact that when you use nanotubes with the graphene, the graphene forms a chain-like network that does a better job of reinforcing the polymer.

In another example, researchers at Rice University have developed electrodes made from carbon nanotubes grown on graphene. The researchers first grew graphene on a metal substrate and then grew carbon nanotubes on the graphene sheet. Because the base of each nanotube is bonded, atom to atom, to the graphene sheet, the nanotube-graphene structure easily allows electrons collected on the nanotubes to flow into the metal substrate of the electrode. This type of very high surface area, very low resistance electrode could be used in energy storage devices such as super-capacitors.

Given that graphene and carbon nanotubes are composed of the same material organized  into different shapes, it’s seems reasonable that the two nanomaterials could be combined. It’s very interesting that the two can then work together to provide better performance than either provides separately for these applications. It will be interesting to see what  other uses researchers come up with to combine the two.

For more information on applications of graphene go to the UnderstandingNano's Graphene Applications webpage at http://www.understandingnano.com/graphene-applications.html . For information on applications of carbon nanotubes go to UnderstandingNano’s Nanotube Applications webpage at http://www.understandingnano.com/nanotubes-carbon.html