Featured Research

from universities, journals, and other organizations

Stellar, metal-free way to make carbon nanotubes

Date:
February 26, 2010
Source:
NASA/Goddard Space Flight Center
Summary:
Space apparently has its own recipe for making carbon nanotubes, one of the most intriguing contributions of nanotechnology here on Earth, and metals are conspicuously missing from the list of ingredients.

Nanotubes can grow on graphite (top) in an unruly mass (middle) according to "space's recipe." The overlapping segments on a single nanotube (bottom) are a telltale sign of the cup-stacked structure. (Image on bottom reproduced from Astrophysical Journal Letters.)
Credit: Yuki Kimura, Tohoku University

Space apparently has its own recipe for making carbon nanotubes, one of the most intriguing contributions of nanotechnology here on Earth, and metals are conspicuously missing from the list of ingredients.

Related Articles


The finding is the surprising by-product of lab experiments designed by Joseph Nuth at NASA's Goddard Space Flight Center, Greenbelt, Md. and his colleagues to address the astronomical question of how carbon gets recycled in the regions of space that spawn stars and planets. The work also could help researchers understand puzzling observations about some supernovas.

In a recent paper in Astrophysical Journal Letters, Nuth's team describes the modest chemical reaction. Unlike current methods for producing carbon nanotubes -- tiny yet strong structures with a range of applications in electronics and, ultimately, perhaps even medicine -- the new approach does not need the aid of a metal catalyst. "Instead, nanotubes were produced when graphite dust particles were exposed to a mixture of carbon monoxide and hydrogen gases," explains Nuth.

"I am amazed at the implications of this paper, not only for astrophysics but also for materials science," says Dick Zare, the chair of the chemistry department at Stanford University, Stanford, Calif. "Could Nature know a new chemistry for making carbon nanotubes that we have yet to discover?"

One indication of that possibility came in 2008, when the long, thin carbon structures known as graphite whiskers -- essentially, bigger cousins of carbon nanotubes -- were identified in three meteorites. That finding offered the tantalizing prospect that a haze of graphite whiskers in space could explain why some supernovas appear dimmer, and therefore farther away, than they should be, according to current models. Yet, "very little is known about graphite whisker formation, and so it is difficult to adequately interpret their discovery," says Marc Fries of NASA's Jet Propulsion Laboratory, Pasadena, Calif.

Fries and Andrew Steele at the Carnegie Institution for Science, Washington, reported the meteorite findings.

Now, the experiments by Nuth's team suggest a possible route for forming such structures. This "is exactly the sort of fundamental approach needed for a meaningful understanding of what graphite whiskers are and what their presence means in the larger context of solar system formation and astronomical observations," Fries explains.

Nuth's approach is a variation of a well-established way to produce gasoline or other liquid fuels from coal. It's known as Fischer-Tropsch synthesis, and researchers suspect that it could have produced at least some of the simple carbon-based compounds in the early solar system. Nuth proposes that the nanotubes yielded by such reactions could be the key to the recycling of the carbon that gets released when carbon-rich grains are destroyed by supernova explosions.

The structure of the carbon nanotubes produced in these experiments was determined by Yuki Kimura, a materials scientist at Tohoku University, Japan, who examined the samples under a powerful transmission electron microscope. He saw particles on which the original smooth graphite gradually morphed into an unstructured region and finally to an area rich in tangled hair-like masses. A closer look with an even more powerful microscope showed that these tendrils were in fact cup-stacked carbon nanotubes, which resemble a stack of Styrofoam cups with the bottoms cut out.

These observations surprised Kimura because carbon nanotubes are typically grown with platinum or another metal as a catalyst, yet Nuth's reaction had used no metals. Kimura checked for contamination but "did not find the presence of metallic particles accompanying the nanotube in the sample," he says.

If further testing indicates that the new method is suitable for materials-science applications, it could supplement, or even replace, the familiar way of making nanotubes, explains Kimura. That possibility "is most exciting and invites yet more study," says Zare.

The findings also might open a new realm of investigation in astronomy, because "we can take the whiskers produced by Joe and interrogate their properties," says Steele.

In particular, researchers can evaluate whether graphite whiskers absorb light, he notes. A positive result would lend credence to the proposition that the presence of these molecules in space affects the observations of some supernovas. The ability to test this hypothesis could start a reaction of its own.


Story Source:

The above story is based on materials provided by NASA/Goddard Space Flight Center. Note: Materials may be edited for content and length.


Cite This Page:

NASA/Goddard Space Flight Center. "Stellar, metal-free way to make carbon nanotubes." ScienceDaily. ScienceDaily, 26 February 2010. <www.sciencedaily.com/releases/2010/02/100224214434.htm>.
NASA/Goddard Space Flight Center. (2010, February 26). Stellar, metal-free way to make carbon nanotubes. ScienceDaily. Retrieved November 21, 2014 from www.sciencedaily.com/releases/2010/02/100224214434.htm
NASA/Goddard Space Flight Center. "Stellar, metal-free way to make carbon nanotubes." ScienceDaily. www.sciencedaily.com/releases/2010/02/100224214434.htm (accessed November 21, 2014).

Share This


More From ScienceDaily



More Matter & Energy News

Friday, November 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Toyota's Hydrogen Fuel-Cell Green Car Soon Available in the US

Toyota's Hydrogen Fuel-Cell Green Car Soon Available in the US

AFP (Nov. 21, 2014) Toyota presented its hydrogen fuel-cell compact car called "Mirai" to US consumers at the Los Angeles auto show. The car should go on sale in 2015 for around $60.000. It combines stored hydrogen with oxygen to generate its own power. Duration: 01:18 Video provided by AFP
Powered by NewsLook.com
Google Announces Improvements To Balloon-Borne Wi-Fi Project

Google Announces Improvements To Balloon-Borne Wi-Fi Project

Newsy (Nov. 21, 2014) In a blog post, Google said its balloons have traveled 3 million kilometers since the start of Project Loon. Video provided by Newsy
Powered by NewsLook.com
NSA Director: China Can Damage US Power Grid

NSA Director: China Can Damage US Power Grid

AP (Nov. 20, 2014) China and "one or two" other countries are capable of mounting cyberattacks that would shut down the electric grid and other critical systems in parts of the United States, according to Adm. Michael Rogers, director of the National Security Agency and hea Video provided by AP
Powered by NewsLook.com
Latest Minivan Crash Tests Aren't Pretty

Latest Minivan Crash Tests Aren't Pretty

Newsy (Nov. 20, 2014) Five minivans were put to the test in head-on crash simulations by the Insurance Institute for Highway Safety. Video provided by Newsy
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