Featured Research

from universities, journals, and other organizations

Smashing new look at nanoribbons: Researchers unzip nanotubes by shooting them at 15,000 mph

Date:
June 30, 2014
Source:
Rice University
Summary:
Scientists have discovered they can unzip nanotubes into graphene nanoribbons without chemicals by firing them at a target at 15,000 miles per hour. Materials scientists discovered that nanotubes that hit a target end first turn into mostly ragged clumps of atoms. But nanotubes that happen to broadside the target unzip into handy ribbons that can be used in composite materials for strength and applications that take advantage of their desirable electrical properties.

Carbon nanotubes can be unzipped into nanoribbons by firing them at high velocity at a target, but only the ones that land lengthwise will unzip, according to researchers at Rice University. Tests evaluated nanotubes that impacted the target at various angles to see the results.
Credit: Ajayan Group/Rice University

Carbon nanotubes "unzipped" into graphene nanoribbons by a chemical process invented at Rice University are finding use in all kinds of projects, but Rice scientists have now found a chemical-free way to unzip them.

The Rice lab of materials scientist Pulickel Ajayan discovered that nanotubes that hit a target end first turn into mostly ragged clumps of atoms. But nanotubes that happen to broadside the target unzip into handy ribbons that can be used in composite materials for strength and applications that take advantage of their desirable electrical properties.

The Rice researchers led by graduate student Sehmus Ozden reported their finding in the American Chemical Society journal Nano Letters.

The result was a surprise, Ozden said. "Until now, we knew we could use mechanical forces to shorten and cut carbon nanotubes. This is the first time we have showed carbon nanotubes can be unzipped using mechanical forces."

The researchers fired pellets of randomly oriented, multiwalled carbon nanotubes from a light gas gun built by the Rice lab of materials scientist Enrique Barrera with funding from NASA. The pellets impacted an aluminum target in a vacuum chamber at about 15,000 miles per hour. When they inspected the resulting carbon rubble, they found nanotubes that smashed into the target end first or at a sharp angle simply deformed into a crumpled nanotube. But tubes that hit lengthwise actually split into ribbons with ragged edges.

"Hypervelocity impact tests are mostly used to simulate the impact of different projectiles on shields, spacecraft and satellites," Ozden said. "We were investigating possible applications for carbon nanotubes in space when we got this result."

The effect was confirmed through molecular simulations. They showed that when multiwalled tubes impact the target, the outer tube flattens, hitting the inside tubes and unzipping them in turn. Single-wall nanotubes do just the opposite; when the tube flattens, the bottom wall hits the inside of the top wall, which unzips from the middle out to the edges.

Ozden explained that the even distribution of stress along the belly-flopping nanotube, which is many times longer than it is wide, breaks carbon bonds in a line nearly simultaneously.

The researchers said 70 to 80 percent of the nanotubes in a pellet unzip to one degree or another.

Ozden said the process eliminates the need to clean chemical residues from nanoribbons produced through current techniques. "One-step, chemical-free, clean and high-quality graphene nanoribbons can be produced using our method. They're potential candidates for next-generation electronic materials," he said.

Co-authors include Pedro Autreto, a postdoctoral researcher at the State University of Campinas, Brazil, who has a complementary appointment at Rice; graduate student Chandra Sekhar Tiwary of Rice and the Indian Institute of Science, Bangalore; graduate student Suman Khatiwada of Rice; Leonardo Machado and Douglas Galvao of the State University of Campinas; and Robert Vajtai, a senior faculty fellow at Rice. Barrera is a professor of materials science and nanoengineering. Ajayan is Rice's Benjamin M. and Mary Greenwood Anderson Professor in Mechanical Engineering and Materials Science and of chemistry, and chair of the Department of Materials Science and NanoEngineering.

The Department of Defense, U.S. Air Force Office of Scientific Research through a Multidisciplinary University Research Institute grant, and the Brazilian agencies National Council for Scientific and Technological Development, Coordination for the Improvement of Higher Education Personnel and the São Paulo Research Foundation supported the research.


Story Source:

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


Journal Reference:

  1. Chandra Sekhar Tiwary, Sehmus Ozden, Pedro A.s. Autreto, Suman Khatiwada, Leonardo Machado, Douglas S Galvao, Robert Vajtai, Enrique V. Barrera, Pulickel M. Ajayan. Unzipping Carbon Nanotubes at High Impact. Nano Letters, 2014; 140610162644004 DOI: 10.1021/nl501753n

Cite This Page:

Rice University. "Smashing new look at nanoribbons: Researchers unzip nanotubes by shooting them at 15,000 mph." ScienceDaily. ScienceDaily, 30 June 2014. <www.sciencedaily.com/releases/2014/06/140630114141.htm>.
Rice University. (2014, June 30). Smashing new look at nanoribbons: Researchers unzip nanotubes by shooting them at 15,000 mph. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2014/06/140630114141.htm
Rice University. "Smashing new look at nanoribbons: Researchers unzip nanotubes by shooting them at 15,000 mph." ScienceDaily. www.sciencedaily.com/releases/2014/06/140630114141.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

Government Approves East Coast Oil Exploration

Government Approves East Coast Oil Exploration

AP (July 18, 2014) — The Obama administration approved the use of sonic cannons to discover deposits under the ocean floor by shooting sound waves 100 times louder than a jet engine through waters shared by endangered whales and turtles. (July 18) Video provided by AP
Powered by NewsLook.com
Sunken German U-Boat Clearly Visible For First Time

Sunken German U-Boat Clearly Visible For First Time

Newsy (July 18, 2014) — The wreckage of the German submarine U-166 has become clearly visible for the first time since it was discovered in 2001. Video provided by Newsy
Powered by NewsLook.com
Obama: U.S. Must Have "smartest Airports, Best Power Grid"

Obama: U.S. Must Have "smartest Airports, Best Power Grid"

Reuters - US Online Video (July 17, 2014) — President Barak Obama stopped by at a lunch counter in Delaware before making remarks about boosting the nation's infrastructure. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com
Crude Oil Prices Bounce Back After Falling Below $100 a Barrel

Crude Oil Prices Bounce Back After Falling Below $100 a Barrel

TheStreet (July 16, 2014) — Oil Futures are bouncing back after tumbling below $100 a barrel for the first time since May yesterday. Jeff Grossman is the president of BRG Brokerage and trades at the NYMEX. Grossman tells TheStreet the Middle East is always a concern for oil traders. Oil prices were pushed down in recent weeks on Libya increasing its production. Supply disruptions in Iraq fading also contributed to prices falling. News from China's economic front showing a growth for the second quarter also calmed fears on its slowdown. Jeff Grossman talks to TheStreet's Susannah Lee on this and more on the Energy Department's Energy Information Administration (EIA) report. Video provided by TheStreet
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