Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Liquid method: pure graphene production

31.05.2010
Research could yield novel composites, touch-screen displays

In a development that could lead to novel carbon composites and touch-screen displays, researchers from Rice University and the Technion-Israel Institute of Technology today unveiled a new method for producing bulk quantities of one-atom-thick sheets of carbon called graphene.

The research is available online in the journal Nature Nanotechnology.

When stacked together, graphene sheets make graphite, which has been commonly used as pencil lead for hundreds of years. It wasn't until 2004 that stand-alone sheets of graphene were first characterized with modern nanotechnological instruments. Since then, graphene has come under intense scrutiny from materials scientists, in part because it is both ultrastrong and highly conductive.

"There are high-throughput methods for making graphene oxide, which is not as conductive as graphene, and there are low-throughput methods for making pure graphene," said lead co-author Matteo Pasquali, professor of chemical and biomolecular engineering and chemistry at Rice. "Our method yields very pure material, and it is based on bulk fluid-processing techniques that have long been used by the chemical industry."

Pasquali said the research team found it could dissolve graphite in chlorosulphonic acid, a common industrial solvent. The researchers had to devise new methods to measure the aggregation of the dissolved graphene flakes, but at the end the team was pleasantly surprised to find that the individual graphene layers in the graphite peeled apart spontaneously. The team was able to dissolve as much as two grams of graphene per liter of acid to produce solutions at least 10 times more concentrated than existing methods.

The researchers took advantage of novel cryogenic techniques for electron microscopy that allowed them to directly image the graphene sheets in the chlorosulfonic acid.

"We applied new methods that we had developed to directly image carbon nanotubes in acid," said co-author Yeshayahu "Ishi" Talmon, professor of chemical engineering at the Technion-Israel Institute of Technology. "This was no small feat considering the nature of the acid and the difficulty of specimen preparation and imaging."

Using the concentrated solutions of dissolved graphene, the scientists made transparent films that were electrically conductive. Such films could be useful in making touch screens that are less expensive than those used in today's smart phones. In addition, the researchers also produced liquid crystals.

"If you can make liquid crystals, you can spin fibers," said study co-author James Tour, Rice's T.T. and W.F. Chao Professor of Chemistry. "In liquid crystals, the individual sheets align themselves into domains, and having some measure of alignment allows you to flow the material through narrow openings to create fibers."

If the method proves useful for making graphene fibers in bulk, it could drive down the cost of the ultrastrong carbon composites used in the aerospace, automotive and construction industries.

The research was funded by the Air Force Office of Scientific Research, the Department of Energy, the Air Force Research Laboratory, the Welch Foundation, the U.S. Army Corps of Engineers and the USA-Israel Binational Science Foundation. Co-authors include Natnael Behabtu, Jay Lomeda, Micah Green, Amanda Higgenbotham, Alexander Sinitskii, Dmitry Kosynkin, Dmitri Tsentalovich and Nicholas Parra-Vasquez, all of Rice's Smalley Institute for Nanoscale Science and Technology; and Judith Schmidt, Ellina Kesselman and Yachin Cohen, all of the Technion-Israel Institute of Technology.

Jade Boyd | EurekAlert!
Further information:
http://www.rice.edu

More articles from Materials Sciences:

nachricht Scientist invents way to trigger artificial photosynthesis to clean air
26.04.2017 | University of Central Florida

nachricht Researchers invent process to make sustainable rubber, plastics
25.04.2017 | University of Delaware

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Millions through license revenues

27.04.2017 | Health and Medicine

The TU Ilmenau develops tomorrow’s chip technology today

27.04.2017 | Information Technology

Scientist invents way to trigger artificial photosynthesis to clean air

26.04.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>