Featured Research

from universities, journals, and other organizations

Method Could Help Carbon Nanotubes Become Commercially Viable

Date:
October 6, 2006
Source:
Northwestern University
Summary:
Carbon nanotubes are intriguing new materials, but a fundamental problem relating to their synthesis has limited their widespread commercial use. Current methods for synthesizing the materials produce mixtures of tubes that differ in their diameter and twist. Now Northwestern University researchers have developed a new method for sorting single-walled carbon nanotubes. The method works by exploiting subtle differences in the buoyant densities of carbon nanotubes as a function of their size and electronic behavior.

Single-walled carbon nanotubes are coated in soap-like molecules called surfactants, then spun at tens of thousands of rotations per minute in an ultracentrifuge. The resulting density gradient sorts the nanotubes according to diameter, twist and electronic structure.
Credit: Zina Deretsky (adapted from Arnold et al.), National Science Foundation

Carbon nanotubes are intriguing new materials which have been highly touted for their exceptional mechanical, thermal, optical and electrical properties.

Related Articles


Researchers worldwide are striving to apply these nanostructures in electronics, high-resolution displays, high-strength composites and biosensors. A fundamental problem relating to their synthesis, however, has limited their widespread use.

Current methods for synthesizing carbon nanotubes produce mixtures of tubes that differ in their diameter and twist. Variations in electronic properties arise from these structural differences, resulting in carbon nanotubes that are unsuitable for most proposed applications.

Now, a new method developed at Northwestern University for sorting single-walled carbon nanotubes promises to overcome this problem. The method works by exploiting subtle differences in the buoyant densities of carbon nanotubes as a function of their size and electronic behavior. The results will be published online Wednesday, Oct. 4, in the inaugural issue of the journal Nature Nanotechnology (October 2006).

"Carbon nanotubes, because of their ultra-small size and excellent materials properties, have excited the scientific community for the last decade," said Mark Hersam, professor of materials science and engineering at Northwestern's McCormick School of Engineering and Applied Science, who led the research team.

"However, due to their inherent heterogeneity, they have not yet realized their full commercial potential," he said. "A scalable and economical method for producing monodisperse carbon nanotubes will enable the proposed applications for these nanomaterials to be explored at an industrially relevant scale."

Using the Northwestern method, carbon nanotubes first are encapsulated in water by soap-like molecules called surfactants. Next, the surfactant-coated nanotubes are sorted in density gradients which are spun at tens of thousands of rotations per minute in an ultracentrifuge. By carefully choosing the surfactants utilized during ultracentrifugation, the researchers found that carbon nanotubes could be sorted by diameter and electronic structure.

As a part of their study, the researchers demonstrated the fabrication of electrical devices that displayed either semiconducting or metallic behavior, depending on the sorted nanotubes used. The researchers also maintain that their technique can be translated to an industrial scale.

"The technique is especially promising for commercial applications," said Hersam, "because large-scale ultracentrifuges have already been developed and shown to be economically viable in the pharmaceutical industry. We anticipate that this precedent can be straightforwardly translated to the production of monodisperse carbon nanotubes."

In addition to Hersam, other authors on the paper are Samuel Stupp, Board of Trustees Professor of Materials Science and Engineering and of Chemistry and a professor of medicine; James Hulvat, research assistant professor of materials science and engineering; and graduate students Michael Arnold and Alexander Green, all from Northwestern.

The research was supported by the National Science Foundation, the U.S. Army Telemedicine and Advanced Technology Research Center and the Department of Energy.


Story Source:

The above story is based on materials provided by Northwestern University. Note: Materials may be edited for content and length.


Cite This Page:

Northwestern University. "Method Could Help Carbon Nanotubes Become Commercially Viable." ScienceDaily. ScienceDaily, 6 October 2006. <www.sciencedaily.com/releases/2006/10/061004180041.htm>.
Northwestern University. (2006, October 6). Method Could Help Carbon Nanotubes Become Commercially Viable. ScienceDaily. Retrieved February 27, 2015 from www.sciencedaily.com/releases/2006/10/061004180041.htm
Northwestern University. "Method Could Help Carbon Nanotubes Become Commercially Viable." ScienceDaily. www.sciencedaily.com/releases/2006/10/061004180041.htm (accessed February 27, 2015).

Share This


More From ScienceDaily



More Matter & Energy News

Friday, February 27, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Elon Musk's Hyperloop Moves Forward

Elon Musk's Hyperloop Moves Forward

Buzz60 (Feb. 27, 2015) Zipping around at 800-miles an hour is coming closer to reality in California. An entire town is being built around Elon Musk&apos;s Hyperloop concept and it wants you to stop in for a ride when it&apos;s ready. Brett Larson is on board. Video provided by Buzz60
Powered by NewsLook.com
Vibrating Bicycle Senses Traffic

Vibrating Bicycle Senses Traffic

Reuters - Innovations Video Online (Feb. 26, 2015) Dutch scientists have developed a smart bicycle that uses sensors, wireless technology and video to warn riders of traffic dangers. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
In Japan, Robot Dogs Are for Life -- And Death

In Japan, Robot Dogs Are for Life -- And Death

AFP (Feb. 25, 2015) Robot dogs are the perfect pet for some in Japan who go to repairmen-turned-vets when their pooch breaks down - while a full Buddhist funeral ceremony awaits those who don&apos;t make it. Duration: 02:40 Video provided by AFP
Powered by NewsLook.com
London Show Dissects History of Forensic Science

London Show Dissects History of Forensic Science

AFP (Feb. 25, 2015) Forensic science, which has fascinated generations with its unravelling of gruesome crime mysteries, is being put under the microscope in an exhibition of real criminal investigations in London. Duration: 00:53 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins