NetComposites
Juniar Spraybooths

NIST’s Stretching Exercises Shed New Light on Nanotubes

23 April 2007

Stretching a carbon nanotube composite, researchers at the National Institute of Standards and Technology (NIST) and the Rochester Institute of Technology (RIT) have made some of the first measurements of how single-walled carbon nanotubes (SWNTs) both scatter and absorb polarized light.

SWNTs have excited materials scientists with the promise of novel materials that have exceptional mechanical, electronic, and optical properties. Recent research on the optics of SWNTs has focused on the behaviour of “excitons” - the pairing of a negatively charged electron with the positively charged “hole” that it leaves behind when it gets excited by a photon into a higher energy state. An important optical characteristic is how excitons in SWNTs impact the way the nanotubes absorb and scatter light.

Measuring that is difficult because the effect depends on the orientation of the nanotubes, and they’re hard to line up neatly. The NIST/RIT team solved the problem elegantly by wrapping SWNTs with DNA to keep them from clumping together, and dispersing them in a polymer. When they heated the polymer and stretched it in one direction, the nanotubes aligned, making the optical measurements possible. The team obtained the first experimental verification of the full optical response of individual semiconducting SWNTs, finding good agreement with theory.

The stretching alignment technique is applicable to a broad range of SWNT experiments where orientation is important, particularly in optics. The work should further our current understanding of how nanotubes interact with light, with important practical applications in optical sensing and the manipulation of individual nanotubes using electromagnetic fields.






Related / You might like...

Compcut 200 Increases Testing Productivity at Renault Sport Racing

Sharp & Tappin has installed and commissioned a Compcut 200 composite plate saw at Renault Sport Racing in Enstone, Oxfordshire, UK.

Electric GT’s Tesla P100DL Features Bcomp Flax Fibre Technologies

Electric GT Holdings and SPV Racing recently unveiled the race-ready version of the EPCS V2.3 Tesla P100DL at Circuit de Barcelona-Catalunya. The car features lightweight body parts made using Bcomp's ampliTex and powerRibs natural fibre composite reinforcement products, contributing to a 500 kg weight reduction over the road edition.

Codem Composites Supports Sahara Force India F1 Team

UK company Codem Composites has provided key bodywork components to support the F1 team Sahara Force India.