Featured Research

from universities, journals, and other organizations

Experiments, Simulations Reveal Birth Secret Of Buckyballs

Date:
October 30, 2007
Source:
Rice University
Summary:
The birth secret of buckyballs -- hollow spheres of carbon no wider than a strand of DNA -- has been caught on tape. An electron microscope video and computer simulations show that "shrink-wrapping" is the key; buckyballs start life as distorted, unstable sheets of graphite, shedding loosely connected threads and chains until only the perfectly spherical buckyballs remain.

Atomic images of the inside of a nanotube show the formation of fullerenes, their reduction to C-60 buckyballs, and their dispersion when heated beyond that point. The images were taken by a transmission electron microscope.
Credit: Image courtesy of Sandia National Laboratories

The birth secret of buckyballs -- hollow spheres of carbon no wider than a strand of DNA -- has been caught on tape by researchers at Sandia National Laboratory and Rice University. An electron microscope video and computer simulations show that "shrink-wrapping" is the key; buckyballs start life as distorted, unstable sheets of graphite, shedding loosely connected threads and chains until only the perfectly spherical buckyballs remain.

Buckyballs were discovered at Rice in 1985, but understanding the intimate details their formation has vexed scientists. Buckyballs form at high temperatures, and one long-standing theory of their genesis is the "hot giant" hypothesis, which suggests that the carbon atoms first assemble by the thousands in flat graphite sheets. Heat distorts the sheets, "shrink wrapping" them into ever-smaller shapes, and buckyballs survive thanks to their perfect symmetry.

"This 'hot evolution' is so rapid that it was nearly impossible to prove or disprove it by experimental observation," said study co-author Boris Yakobson, professor of mechanical engineering and materials science at Rice. "Sandia's Jianyu Huang solved this problem by creating an ingenious, controllable heat bath inside a 10-nanometer-wide nanotube. That allowed him to capture video of giant fullerenes gradually shrinking."

Huang, who performed the experiments while at Boston College and analyzed the data at Sandia, said the results constitute the first experimental evidence for the 'shrink-wrapping' and 'hot-giant' fullerene birth mechanisms.

That is, heating bends single-atomic-layer carbon sheets into nano bowls, and then adds more carbon atoms to the edge of the bowls until the formation of giant fullerenes — larger, less stable versions of the C-60 molecule. Continued application of heat reduces these fullerenes — “shrink-wrapping” is the favored term — to the size of stable C-60 molecules, the buckyball: the smallest stable arrangement of carbon atoms in that shape.

In further heating, the buckyball vanishes, providing more proof that the buckyball stage had been reached.

Huang captured the high-resolution images using a transmission electron microscope (TEM). The video shows a large fullerene, with an estimated 2,000 atoms of carbon gradually shrinking. It confirmed predictions about the atomic mechanisms that Yakobson's team at Rice had made based on detailed computer simulations.

"If heat is sustained, as it was when we took these images, the fullerenes undergo a further shrinking and vanish," Huang said. "This confirms an aspect of 'shrink wrapping' theory that was predicted by Rice's Rick Smalley and Bob Curl made shortly after they discovered fullerenes."

Huang and Yakobson said it may be possible to exploit the findings to control the fullerene formation process and tailor fullerenes for a variety of applications.

About Buckyballs

Buckyballs — more formally known as buckminsterfullerene C-60 — are carbon-linked nanostructures named for their resemblance to the geodesic dome macrostructures favored for their strength by environmentalist Buckminster Fuller.

In addition to the strength generated by their carbon-carbon bonds — “the strongest chemical bonds in Mother Nature,” says Huang, who still seems awed by the properties of the nanomaterial — the structure forms a relatively impermeable cage that conceivably could safely transport molecules of hydrogen for fuel, or tiny doses of medicine to targeted sites within the human body.

But before their widespread use is possible, buckyballs have to be available in large numbers. To achieve that, better understanding of how they form is crucial.

Video available at: http://www.youtube.com/watch?v=NSNlE8AreeM

The research is available online and slated to appear in the Oct. 26 issue of Physical Review Letters (PRL).

Co-authors of the research include research scientist Feng Ding and graduate student Kun Jiao, both of Rice. The research was funded by the Office of Naval Research and the Department of Energy's Center for Integrated Nanotechnologies.


Story Source:

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


Cite This Page:

Rice University. "Experiments, Simulations Reveal Birth Secret Of Buckyballs." ScienceDaily. ScienceDaily, 30 October 2007. <www.sciencedaily.com/releases/2007/10/071026162143.htm>.
Rice University. (2007, October 30). Experiments, Simulations Reveal Birth Secret Of Buckyballs. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2007/10/071026162143.htm
Rice University. "Experiments, Simulations Reveal Birth Secret Of Buckyballs." ScienceDaily. www.sciencedaily.com/releases/2007/10/071026162143.htm (accessed July 23, 2014).

Share This




More Matter & Energy News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Robot Parking Valet Creates Stress-Free Travel

Robot Parking Valet Creates Stress-Free Travel

AP (July 23, 2014) 'Ray' the robotic parking valet at Dusseldorf Airport in Germany lets travelers to avoid the hassle of finding a parking spot before heading to the check-in desk. (July 23) Video provided by AP
Powered by NewsLook.com
Boeing Ups Outlook on 52% Profit Jump

Boeing Ups Outlook on 52% Profit Jump

Reuters - Business Video Online (July 23, 2014) Commercial aircraft deliveries rose seven percent at Boeing, prompting the aerospace company to boost full-year profit guidance- though quarterly revenues missed analyst estimates. Bobbi Rebell reports. Video provided by Reuters
Powered by NewsLook.com
Europe's Car Market on the Rebound?

Europe's Car Market on the Rebound?

Reuters - Business Video Online (July 23, 2014) Daimler kicks off a round of second-quarter earnings results from Europe's top carmakers with a healthy set of numbers - prompting hopes that stronger sales in Europe will counter weakness in emerging markets. Hayley Platt reports. Video provided by Reuters
Powered by NewsLook.com
9/11 Commission Members Warn of Terror "fatigue" Among American Public

9/11 Commission Members Warn of Terror "fatigue" Among American Public

Reuters - US Online Video (July 22, 2014) Ten years after releasing its initial report, members of the 9/11 Commission warn of the "waning sense of urgency" in combating terrorists attacks. Mana Rabiee reports. Video provided by Reuters
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:
from the past week

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