Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > NIST develops rapid method for judging nanotube purity

Abstract:
Researchers at the National Institute of Standards and Technology (NIST) have developed a sensitive new method for rapidly assessing the quality of carbon nanotubes. Initial feasibility tests show that the method not only is faster than the standard analytic technique but also effectively screens much smaller samples for purity and consistency and better detects sample variability.

NIST develops rapid method for judging nanotube purity

Washington, DC | Posted on February 2nd, 2007

Carbon nanotubes have unique properties, and thermal and electrical conductance, that could be useful in fields such as aerospace, microelectronics and biotechnology. However, these properties may vary widely depending on nanotube dimensions, uniformity and chemical purity. Nanotube samples typically contain a significant percentage of more ordinary forms of carbon as well as metal particles left over from catalysts used in manufacturing. The new NIST method, described at a conference last week,* involves spraying nanotube coatings onto a quartz crystal, gradually heating the coated crystal, and measuring the change in its resonant frequency as different forms of carbon vaporize. The frequency changes in proportion to the mass of the coating, and scientists use this as a measure of stability at different temperatures to gauge consistency among samples. The quartz crystal technique, which can reveal mass changes of just a few nanograms, already is used in other contexts to detect toxic gases and measure molecular interactions.

NIST researchers tested dozens of samples from a batch of commercial single-walled carbon nanotubes, comparing results of the new method with those from a standard technique, thermogravimetric analysis, and confirming results with scanning electron microscopy. Both methods revealed that the samples contained large amounts of amorphous carbon as well as residual metal particles. But the quartz crystal method could obtain results from just micrograms of material, compared to milligrams for thermogravimetric analysis, and also revealed several orders of magnitude more variability in the samples tested. The new technique also uses simpler equipment.

Although the differences among nanotube samples may appear subtle, they may still affect product viability, because even small variations in material composition can affect electrical and thermal behavior, and lack of uniformity may demand higher loads of nanotubes, which are expensive. NIST scientists carried out the tests with the help of students from the University of Colorado-Boulder and Rensselaer Polytechnic Institute, Troy, N.Y.

* S.A. Hooker, R. Geiss, R. Schilt and A. Kar. Rapid inspection of carbon nanotube quality. Paper presented Jan. 25 at the 31st International Cocoa Beach Conference and Exposition on Advanced Ceramics and Composites, Daytona Beach, Fla.

####

About NIST
Founded in 1901, NIST is a non-regulatory federal agency within the U.S. Commerce Department's Technology Administration. NIST's mission is to promote U.S. innovation and industrial competitiveness by advancing measurement science, standards, and technology in ways that enhance economic security and improve our quality of life.

For more information, please click here

Contacts:
Laura Ost

303-497-4880

Copyright © NIST

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

Nanotubes/Buckyballs

Carbon nanotube fibers make superior links to brain: Rice University invention provides two-way communication with neurons March 25th, 2015

Iranian Scientists Eliminate Expensive Materials from Diabetes Diagnosis Sensors March 25th, 2015

Effect of Carbon Nanotubes on Properties of Cement Composites Studied in Iran March 23rd, 2015

First proof of isolated attosecond pulse generation at the carbon K-edge March 20th, 2015

Discoveries

Chemists make new silicon-based nanomaterials March 27th, 2015

UT Dallas engineers twist nanofibers to create structures tougher than bulletproof vests March 27th, 2015

Novel nanoparticle therapy promotes wound healing March 27th, 2015

Designer's toolkit for dynamic DNA nanomachines: Arm-waving nanorobot signals new flexibility in DNA origami March 27th, 2015

Announcements

UT Dallas engineers twist nanofibers to create structures tougher than bulletproof vests March 27th, 2015

Novel nanoparticle therapy promotes wound healing March 27th, 2015

Designer's toolkit for dynamic DNA nanomachines: Arm-waving nanorobot signals new flexibility in DNA origami March 27th, 2015

Using magnetic fields to understand high-temperature superconductivity: Los Alamos explores experimental path to potential 'next theory of superconductivity' March 27th, 2015

Human Interest/Art

2015 Nanonics Image Contest January 29th, 2015

OCSiAl supports NanoART Imagery Contest January 23rd, 2015

EnvisioNano: An image contest hosted by the National Nanotechnology Initiative (NNI) January 22nd, 2015

Oxford Instruments Asylum Research Announces AFM Image Contest Winners January 11th, 2015

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2015 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE