Navigation Links
Columbia engineering team discovers graphene's weakness
Date:11/30/2010

New York, NY November 29, 2010 In 2008, experiments at The Fu Foundation School of Engineering and Applied Science at Columbia University established pure graphene, a single layer of graphite only one atom thick, as the strongest material known to mankind. This raised a question for Chris Marianetti, Assistant Professor in Columbia Engineering's Department of Applied Physics and Applied Mathematics: how and why does graphene break?

Using quantum theory and supercomputers, Marianetti has revealed the mechanisms of mechanical failure of pure graphene under tensile stress. In a paper recently accepted for publication in the journal Physical Review Letters, he shows that, when graphene is subject to strain equal in all directions, it morphs into a new structure which is mechanically unstable.

Marianetti says this failure mechanism is a novel soft-mode phonon instability. A phonon is a collective vibrational mode of atoms within a crystal, similar to a wave in a liquid. The fact that a phonon becomes "soft" under tensile strain means that the system can lower its energy by distorting the atoms along the vibrational mode and transitioning to a new crystalline arrangement. Under sufficient strain, graphene develops a particular soft-mode that causes the honeycomb arrangement of carbon atoms to be driven towards isolated hexagonal rings. This new crystal is structurally weaker, resulting in the mechanical failure of the graphene sheet.

"This is exciting on many different levels," Marianetti notes. "Soft modes were first recognized in the 1960s in the context of ferroelectric phase transitions, but they have never been directly linked to fracture. Typically, defects in a material will always cause failure to happen prematurely, but the pristine nature of graphene allows one to test our prediction. We have already outlined some interesting new experiments to directly observe our theoretical prediction of the soft mode."

Marianetti added that this is the first time a soft optical phonon has ever been linked to mechanical failure and that therefore it is likely that this novel failure mechanism is not exclusive to graphene but may be prevalent in other very thin materials. "With nanotechnology becoming increasingly ubiquitous, understanding the nature of mechanical behavior in low dimensional systems such as graphene is of great importance. We think strain may be a means to engineer the properties of graphene, and therefore understanding its limits is critical." The research was funded by the National Science Foundation.

Marianetti's research interests lie in the use of classical and quantum mechanics to model the behavior of materials at the atomic scale. In particular, he is focused on applying these techniques to materials with potential for energy storage and conversion. Current applications in his research program range from nuclear materials such as plutonium to rechargeable battery materials such as cobalt oxides.


'/>"/>

Contact: Holly Evarts
holly@engineering.columbia.edu
212-854-3206
Columbia University
Source:Eurekalert

Related biology technology :

1. OncoGenex Pharmaceuticals Named Life Sciences Company of the Year by LifeSciences British Columbia
2. Leading North American Emergency Medical Services Provider British Columbia Ambulance Service Selects NICE Inform for Improved Service
3. American Oriental Bioengineering Announces Participation in September Investor Conferences
4. Online Systems Engineering Master's Program Attracts Engineers from Fortune 500 Firms
5. NSF awards 14 materials research science and engineering centers
6. Genetic Engineering & Biotechnology News reports on growing role of molecular diagnostics
7. Genstruct Expands Team with New VP of Engineering
8. Engineering nanoparticles for maximum strength
9. American Oriental Bioengineering Completes Two Acquisitions
10. American Oriental Bioengineering, Inc. to Report Third Quarter 2008 Financial Results
11. American Oriental Bioengineering Announces Participation in November Investor Conferences
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/24/2016)... 24, 2016 Epic Sciences unveiled a ... susceptible to PARP inhibitors by targeting homologous recombination ... The new test has already been incorporated into ... cancer types. Over 230 clinical trials ... pathways, including PARP, ATM, ATR, DNA-PK and WEE-1. ...
(Date:6/23/2016)... , June 23, 2016   Boston ... of novel compounds designed to target cancer stemness ... has been granted Orphan Drug Designation from the ... treatment of gastric cancer, including gastroesophageal junction (GEJ) ... inhibitor designed to inhibit cancer stemness pathways by ...
(Date:6/23/2016)... 23, 2016  The Prostate Cancer Foundation (PCF) is pleased to ... faster cures for prostate cancer. Members of the Class of 2016 were selected ... Read More About the Class of 2016 PCF Young Investigators ... ... ...
(Date:6/23/2016)... ... June 23, 2016 , ... In a new case report published today ... a patient who developed lymphedema after being treated for breast cancer benefitted from an ... paradigm for dealing with this debilitating, frequent side effect of cancer treatment. ...
Breaking Biology Technology:
(Date:6/9/2016)... , June 9, 2016 ... deploy Teleste,s video security solution to ensure the safety of ... during the major tournament Teleste, an ... systems and services, announced today that its video security solution ... to back up public safety across the country. The ...
(Date:6/2/2016)... LONDON , June 2, 2016 ... Systems, Manned Platforms, Unmanned Systems, Physical Infrastructure, Support & ... intelligence provider visiongain offers comprehensive analysis of ... that this market will generate revenues of $17.98 billion ... Systems acquired DVTEL Inc, a leader in software and ...
(Date:5/12/2016)... 2016 WearablesResearch.com , a brand of ... results from the Q1 wave of its quarterly wearables ... consumers, receptivity to a program where they would receive ... insurance company. "We were surprised to see ... Michael LaColla , CEO of Troubadour Research, "primarily because ...
Breaking Biology News(10 mins):