Navigation Links
Frustration inspires new form of graphene
Date:10/14/2011

They're the building block of graphite ultra-thin sheets of carbon, just one atom thick, whose discovery was lauded in 2010 with a Nobel Prize in Physics.

The seemingly simple material is graphene, and many researchers believe it has great potential for many applications, from electronic devices to high-performance composite materials.

Graphene is extremely strong, an excellent conductor, and with no internal structure at all, it offers an abundance of surface area much like a sheet of paper.

When it comes to producing and utilizing graphene on a large scale, however, researchers have come upon a major problem: the material's tendency to aggregate. Like paper, graphene sheets easily stack into piles, thus greatly reducing their surface area and making them unprocessable.

Researchers at Northwestern University have now developed a new form of graphene that does not stack. The new material inspired by a trash can full of crumpled-up papers is made by crumpling the graphene sheets into balls.

A paper describing the findings, "Compression and Aggregation-resistant Particles of Crumpled Soft Sheets," was published October 13 in the journal ACS Nano.

Graphene-based materials are very easily aggregated due to the strong interaction between the sheets, called "Van der Waals attraction." Therefore, common steps in materials processing, such as heating, solvent washing, compression, and mixing with other materials, can greatly affect how the sheets are stacked. When the paper-like sheets band together picture a deck of cards their surface area is lost; with just a fraction of its original surface area available, the material becomes less effective. Stacked graphene sheets also become rigid and lose their processability.

Some scientists have tried to physically keep the sheets apart by inserting non-carbon "spacers" between them, but that changes the chemical composition of the material. When graphene is crumpled into balls, however, its surface area remains available and the material remains pure.

"If you imagine a trash can filled with paper crumples, you really get the idea," says Jiaxing Huang, Morris E. Fine Junior Professor in Materials and Manufacturing, the lead researcher of the study. "The balls can stack up into a tight structure. You can crumple them as hard as you want, but their surface area won't be eliminated, unlike face-to-face stacking."

"Crumpled paper balls usually express an emotion of frustration, a quite common experience in research," Huang says, "However, here 'frustration' quite appropriately describes why these particles are resistant to aggregation because their uneven surface frustrates or prevents tight face-to-face packing no matter how you process them."

To make crumpled graphene balls, Huang and his team created freely suspended water droplets containing graphene-based sheets, then used a carrier gas to blow the aerosol droplets through a furnace. As the water quickly evaporated, the thin sheets were compressed by capillary force into near-spherical particles.

The resulting crumpled graphene particles have the same electrical properties as the flat sheets but are more useful for applications that require large amounts of the material. The ridges formed in the crumpling process render the particles a strain-hardening property; the harder you compress them, the stronger they become. Therefore, the crumpled graphene balls are remarkably stable against mechanical deformation, Huang said.

"We expect this to serve as a new graphene platform to investigate application in energy storage and energy conversion," Huang said.


'/>"/>

Contact: Megan Fellman
fellman@northwestern.edu
847-491-3115
Northwestern University
Source:Eurekalert

Related biology technology :

1. Suzanne Somers, Renowned Author, Medical Advocate, and Official Spokesperson for NeoStem, Inc., Inspires the Audience on The Ellen Degeneres Show
2. Haydon Kerk Motion Solutions Inspires Next Generation of Innovators as Silver Supplier of the FIRST Robotics Competition
3. UT professors pathogen research inspires robotics design for medicine and military
4. joimax® Inspires Thai-German Neurosurgery Congress Participants for TESSYS®
5. Graphene pioneers follow in Nobel footsteps
6. New graphene-based material clarifies graphite oxide chemistry
7. Researchers discover method for mass production of nanomaterial graphene
8. Light-speed nanotech: Controlling the nature of graphene
9. Scientists prove graphenes edge structure affects electronic properties
10. Graphene yields secrets to its extraordinary properties
11. Graphene may have advantages over copper for IC interconnects at the nanoscale
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/23/2016)... FRANCISCO , June 23, 2016   EpiBiome ... has secured $1 million in debt financing from Silicon ... ramp up automation and to advance its drug development ... its new facility. "SVB has been an ... beyond the services a traditional bank would provide," said ...
(Date:6/23/2016)...  Blueprint Bio, a company dedicated to identifying, protecting ... has closed its Series A funding round, according to ... "We have received a commitment from Forentis Fund that ... meet our current goals," stated Matthew Nunez . ... complete validation on the current projects in our pipeline, ...
(Date:6/23/2016)... ... June 23, 2016 , ... Velocity Products, ... tools designed, tuned and optimized exclusively for Okuma CNC machining centers at The ... of a collaboration among several companies with expertise in toolholding, cutting tools, machining ...
(Date:6/22/2016)... NEW YORK , June 22, 2016 /PRNewswire/ ... the growing next generation sequencing (NGS) market include ... adoption of smaller sequencers.  More accessible and affordable ... led to growing demand for consumables including sample ... The Market for Sample Preparation for Next ...
Breaking Biology Technology:
(Date:5/20/2016)... 20, 2016  VoiceIt is excited to announce ... By working together, VoiceIt and VoicePass ... and VoicePass take slightly different approaches to voice ... security and usability. ... new partnership. "This marketing and technology ...
(Date:5/12/2016)... May 12, 2016 WearablesResearch.com , a ... the overview results from the Q1 wave of its ... wave was consumers, receptivity to a program where they ... a health insurance company. "We were surprised ... says Michael LaColla , CEO of Troubadour Research, ...
(Date:5/3/2016)... 3, 2016  Neurotechnology, a provider of high-precision ... Automated Biometric Identification System (ABIS) , a complete ... MegaMatcher ABIS can process multiple complex biometric transactions ... of fingerprint, face or iris biometrics. It leverages ... and MegaMatcher Accelerator , which have been ...
Breaking Biology News(10 mins):