Nanotechnology Now

Our NanoNews Digest Sponsors


Heifer International

Wikipedia Affiliate Button

Home > Press > Even with Defects, Graphene is Strongest Material in the World: New Study Reveals Strength of CVD Graphene

Abstract:
In a new study, published in Science May 31, 2013, Columbia Engineering researchers demonstrate that graphene, even if stitched together from many small crystalline grains, is almost as strong as graphene in its perfect crystalline form. This work resolves a contradiction between theoretical simulations, which predicted that grain boundaries can be strong, and earlier experiments, which indicated that they were much weaker than the perfect lattice.

Even with Defects, Graphene is Strongest Material in the World: New Study Reveals Strength of CVD Graphene

New York, NY | Posted on May 31st, 2013

Graphene consists of a single atomic layer of carbon, arranged in a honeycomb lattice. "Our first Science paper, in 2008, studied the strength graphene can achieve if it has no defects—its intrinsic strength," says James Hone, professor of mechanical engineering, who led the study with Jeffrey Kysar, professor of mechanical engineering. "But defect-free, pristine graphene exists only in very small areas. Large-area sheets required for applications must contain many small grains connected at grain boundaries, and it was unclear how strong those grain boundaries were. This, our second Science paper, reports on the strength of large-area graphene films grown using chemical vapor deposition (CVD), and we're excited to say that graphene is back and stronger than ever."

The study verifies that commonly used methods for post-processing CVD-grown graphene weaken grain boundaries, resulting in the extremely low strength seen in previous studies. The Columbia Engineering team developed a new process that prevents any damage of graphene during transfer. "We substituted a different etchant and were able to create test samples without harming the graphene," notes the paper's lead author, Gwan-Hyoung Lee, a postdoctoral fellow in the Hone lab. "Our findings clearly correct the mistaken consensus that grain boundaries of graphene are weak. This is great news because graphene offers such a plethora of opportunities both for fundamental scientific research and industrial applications."

In its perfect crystalline form, graphene (a one-atom-thick carbon layer) is the strongest material ever measured, as the Columbia Engineering team reported in Science in 2008—so strong that, as Hone observed, "it would take an elephant, balanced on a pencil, to break through a sheet of graphene the thickness of Saran Wrap." For the first study, the team obtained small, structurally perfect flakes of graphene by mechanical exfoliation, or mechanical peeling, from a crystal of graphite. But exfoliation is a time-consuming process that will never be practical for any of the many potential applications of graphene that require industrial mass production.

Currently, scientists can grow sheets of graphene as large as a television screen by using chemical vapor deposition (CVD), in which single layers of graphene are grown on copper substrates in a high-temperature furnace. One of the first applications of graphene may be as a conducting layer in flexible displays.

"But CVD graphene is ‘stitched' together from many small crystalline grains—like a quilt—at grain boundaries that contain defects in the atomic structure," Kysar explains. "These grain boundaries can severely limit the strength of large-area graphene if they break much more easily than the perfect crystal lattice, and so there has been intense interest in understanding how strong they can be."

The Columbia Engineering team wanted to discover what was making CVD graphene so weak. In studying the processing techniques used to create their samples for testing, they found that the chemical most commonly used to remove the copper substrate also causes damage to the graphene, severely degrading its strength.

Their experiments demonstrated that CVD graphene with large grains is exactly as strong as exfoliated graphene, showing that its crystal lattice is just as perfect. And, more surprisingly, their experiments also showed that CVD graphene with small grains, even when tested right at a grain boundary, is about 90% as strong as the ideal crystal.

"This is an exciting result for the future of graphene, because it provides experimental evidence that the exceptional strength it possesses at the atomic scale can persist all the way up to samples inches or more in size," says Hone. "This strength will be invaluable as scientists continue to develop new flexible electronics and ultrastrong composite materials."

Strong, large-area graphene can be used for a wide variety of applications such as flexible electronics and strengthening components—potentially, a television screen that rolls up like a poster or ultrastrong composites that could replace carbon fiber. Or, the researchers speculate, a science fiction idea of a space elevator that could connect an orbiting satellite to Earth by a long cord that might consist of sheets of CVD graphene, since graphene (and its cousin material, carbon nanotubes) is the only material with the high strength-to-weight ratio required for this kind of hypothetical application.

The team is also excited about studying 2D materials like graphene. "Very little is known about the effects of grain boundaries in 2D materials," Kysar adds. "Our work shows that grain boundaries in 2D materials can be much more sensitive to processing than in 3D materials. This is due to all the atoms in graphene being surface atoms, so surface damage that would normally not degrade the strength of 3D materials can completely destroy the strength of 2D materials. However with appropriate processing that avoids surface damage, grain boundaries in 2D materials, especially graphene, can be nearly as strong as the perfect, defect-free structure."

The study was supported by grants from the Air Force Office of Scientific Research and the National Science Foundation.

####

About Columbia Engineering
Columbia University's Fu Foundation School of Engineering and Applied Science, founded in 1864, offers programs in nine departments to both undergraduate and graduate students. With facilities specifically designed and equipped to meet the laboratory and research needs of faculty and students, Columbia Engineering is home to NSF-NIH funded centers in genomic science, molecular nanostructures, materials science, and energy, as well as one of the world’s leading programs in financial engineering. These interdisciplinary centers are leading the way in their respective fields while individual groups of engineers and scientists collaborate to solve some of modern society’s more difficult challenges

For more information, please click here

Contacts:
Holly Evarts
Director
Strategic Communications and Media Relations
212-854-3206 (o)
347-453-7408 (c)

Copyright © Columbia Engineering

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

News and information

New theory could lead to new generation of energy friendly optoelectronics: Researchers at Queen's University Belfast and ETH Zurich, Switzerland, have created a new theoretical framework which could help physicists and device engineers design better optoelectronics August 23rd, 2016

New flexible material can make any window 'smart' August 23rd, 2016

University of Puerto Rico and NASA back in the news – XEI reports August 23rd, 2016

Nanoparticles that speed blood clotting may someday save lives August 23rd, 2016

Display technology/LEDs/SS Lighting/OLEDs

McMaster researchers resolve a problem that has been holding back a technological revolution August 18th, 2016

Leading Advanced Materials Manufacturer Pixelligent Closes $10.4 Million in Funding: Capital Will Boost Capacity for North American Manufacturing, Drive Asian Expansion, and Continue Innovation in Solid State Lighting and OLED Display Applications August 16th, 2016

Towards a better screen; New molecules promise cheaper, more efficient OLED displays August 9th, 2016

Graphene/ Graphite

'Sniffer plasmons' could detect explosives: Scientists have proposed a graphene-based spaser that can detect even small amounts of various substances, including explosives August 16th, 2016

Nanoribbons in solutions mimic nature: Rice University scientists test graphene ribbons' abilities to integrate with biological systems August 15th, 2016

Lithium-ion batteries: Capacity might be increased by 6 times August 9th, 2016

Flexible Electronics

See-through circuitry: New method makes AZO a viable and cheap alternative for transparent electronics August 15th, 2016

Challenging the 'rigidity' for smart soft electronics August 5th, 2016

Govt.-Legislation/Regulation/Funding/Policy

New theory could lead to new generation of energy friendly optoelectronics: Researchers at Queen's University Belfast and ETH Zurich, Switzerland, have created a new theoretical framework which could help physicists and device engineers design better optoelectronics August 23rd, 2016

New flexible material can make any window 'smart' August 23rd, 2016

Researchers reduce expensive noble metals for fuel cell reactions August 22nd, 2016

Spider silk: Mother Nature's bio-superlens August 22nd, 2016

Nanotubes/Buckyballs/Fullerenes

McMaster researchers resolve a problem that has been holding back a technological revolution August 18th, 2016

'Second skin' protects soldiers from biological and chemical agents August 5th, 2016

Carbon nanotube 'stitches' make stronger, lighter composites: Method to reinforce these materials could help make airplane frames lighter, more damage-resistant August 4th, 2016

Easier, faster, cheaper: A full-filling approach to making nanotubes of consistent quality: Approach opens a straightforward route for engineering the properties of single-wall carbon nanotubes July 19th, 2016

Discoveries

New theory could lead to new generation of energy friendly optoelectronics: Researchers at Queen's University Belfast and ETH Zurich, Switzerland, have created a new theoretical framework which could help physicists and device engineers design better optoelectronics August 23rd, 2016

New flexible material can make any window 'smart' August 23rd, 2016

Nanoparticles that speed blood clotting may someday save lives August 23rd, 2016

Researchers reduce expensive noble metals for fuel cell reactions August 22nd, 2016

Materials/Metamaterials

New flexible material can make any window 'smart' August 23rd, 2016

Researchers reduce expensive noble metals for fuel cell reactions August 22nd, 2016

Industrial Nanotech, Inc. Provides Shareholder Update August 22nd, 2016

Carbodeon Ltd Oy Closes EUR 1.5 million Funding Round From Straightforward Capital: Carbodeon will accelerate its nanodiamonds business and expand manufacturing capacity August 21st, 2016

Announcements

New theory could lead to new generation of energy friendly optoelectronics: Researchers at Queen's University Belfast and ETH Zurich, Switzerland, have created a new theoretical framework which could help physicists and device engineers design better optoelectronics August 23rd, 2016

New flexible material can make any window 'smart' August 23rd, 2016

University of Puerto Rico and NASA back in the news – XEI reports August 23rd, 2016

Nanoparticles that speed blood clotting may someday save lives August 23rd, 2016

Military

Nanoparticles that speed blood clotting may someday save lives August 23rd, 2016

Curbing the life-long effects of traumatic brain injury August 19th, 2016

Lab team spins ginger into nanoparticles to heal inflammatory bowel disease August 19th, 2016

Down to the wire: ONR researchers and new bacteria August 18th, 2016

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







Car Brands
Buy website traffic