Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers at Rensselaer Polytechnic Institute Develop New Method for Mass-Producing Graphene

22.06.2010
New, Simple Technique Enables Large-Scale Production of Graphene at Room Temperature; Researchers Use Graphene to Build Chemical Sensors, Ultracapacitors

Researchers at Rensselaer Polytechnic Institute have developed a simple new method for producing large quantities of the promising nanomaterial graphene. The new technique works at room temperature, needs little processing, and paves the way for cost-effective mass production of graphene.

An atom-thick sheet of carbon arranged in a honeycomb structure, graphene has unique mechanical and electrical properties and is considered a potential heir to copper and silicon as the fundamental building block of nanoelectronics. Since graphene’s discovery in 2004, researchers have been searching for an easy method to produce it in bulk quantities.

A team of interdisciplinary researchers, led by Swastik Kar, research assistant professor in the Department of Physics, Applied Physics, and Astronomy at Rensselaer, has brought science a step closer to realizing this important goal. By submerging graphite in a mixture of dilute organic acid, alcohol, and water, and then exposing it to ultrasonic sound, the team discovered that the acid works as a “molecular wedge, ” which separates sheets of graphene from the parent graphite. The process results in the creation of large quantities of undamaged, high-quality graphene dispersed in water. Kar and team then used the graphene to build chemical sensors and ultracapacitors.

“There are other known techniques for fabricating graphene, but our process is advantageous for mass production as it is low cost, performed at room temperature, devoid of any harsh chemicals, and thus is friendly to a number of technologies where temperature and environmental limitations exist,” Kar said. “The process does not need any controlled environment chambers, which enhances its simplicity without compromising its scalability. This simplicity enabled us to directly demonstrate high-performance applications related to environmental sensing and energy storage, which have become issues of global importance.”

Results of the study, titled “Stable Aqueous Dispersions of Non-Covalently Functionalized Graphene from Graphite and their Multifunctional High-Performance Applications,” were published online Thursday, June 17, 2010, by the journal Nano Letters. The study will also be the cover story of the November print edition of Nano Letters.

Graphene eluded scientists for years but was finally made in the laboratory in 2004 with the help of a common office supply – clear adhesive tape. Graphite, the common material used in most pencils, is made up of countless layers of graphene. Researchers at first simply used the gentle stickiness of tape to pull layers of graphene from a piece of graphite.

Today, graphene fabrication is much more sophisticated. The most commonly used method, however, which involves oxidizing graphite and reducing the oxide at a later stage in the process, results in a degradation of graphene’s attractive conductive properties, Kar said. His team took a different route.

The researchers dissolved 1-pyrenecarboxylic acid (PCA) in a solution of water and methanol, and then introduced bulk graphite powder. The pyrene part of PCA is mostly hydrophobic, and clings to the surface of the also-hydrophobic graphite. The mixture is exposed to ultrasonic sound, which vibrates and agitates the graphite. As the molecular bonds holding together the graphene sheets in graphite start to weaken because of the agitation, the PCA also exploits these weakening bonds and works its way between the layers of graphene that make up the graphite. Ultimately, this coordinated attack results in layers of graphene flaking off of the graphite and into the water. The PCA also helps ensure the graphene does not clump and remains evenly dispersed in the water. Water is benign, and is an ideal vehicle through which graphene can be introduced into new applications and areas of research, Kar said.

“We believe that our method also will be useful for applications of graphene which require an aqueous medium, such as biomolecular experiments with living cells, or investigations involving glucose or protein interactions with graphene,” he said.

Using ultrathin membranes fabricated from graphene, the research team developed chemical sensors that can easily identify ethanol from within a mixture of different gases and vapors. Such a sensor could possibly be used as an industrial leakage detector or a breath-alcohol analyzer. The researchers also used the graphene to build an ultra-thin energy-storage device. The double-layer capacitor demonstrated high specific capacitance, power, and energy density, and performed far superior to similar devices fabricated in the past using graphene. Both devices show great promise for further performance enhancements, Kar said.

Co-authors on the Nano Letters paper are Rensselaer Post Doctoral Research Associate Xiaohong An; Assistant Professor Kim M. Lewis; Clinical Professor and Center for Integrated Electronics Associate Director Morris Washington; and Professor Saroj Nayak, all of the Department of Physics, Applied Physics, and Astronomy; Rensselaer post-doctoral researcher Trevor Simmons of the Department of Chemistry and Chemical Biology; along with Rakesh Shah, Christopher Wolfe, and Saikat Talapatra of the Department of Physics at Southern Illinois University Carbondale.

The research project was supported by the Interconnect Focus Center New York at Rensselaer, as well as the National Science Foundation (NSF) Division of Electrical, Communications and Cyber Systems.

For more information on Kar’s research, visit his website at:

http://www.rpi.edu/dept/phys/faculty/profiles/kar.html
For more information on graphene research at Rensselaer, visit:
Graphene Outperforms Carbon Nanotubes for Creating Stronger, More Crack-Resistant Materials - http://news.rpi.edu/update.do?artcenterkey=2715
Student Inventor Tackles Challenge of Hydrogen Storage - http://news.rpi.edu/update.do?artcenterkey=2690
Light-Speed Nanotech: Controlling the Nature of Graphene - http://news.rpi.edu/update.do?artcenterkey=2528
Graphene Nanoelectronics: Making Tomorrow’s Computers from a Pencil Trace - http://news.rpi.edu/update.do?artcenterkey=2253

Published June 21, 2010

Contact: Michael Mullaney
Phone: (518) 276-6161
E-mail: mullam@rpi.edu

Michael Mullaney | Rensselaer Polytechnic Institute
Further information:
http://www.rpi.edu

More articles from Interdisciplinary Research:

nachricht The Internet of Things: TU Graz researchers increase the dependability of smart systems
18.02.2019 | Technische Universität Graz

nachricht Stanford researchers create a wireless, battery-free, biodegradable blood flow sensor
09.01.2019 | Stanford University

All articles from Interdisciplinary Research >>>

The most recent press releases about innovation >>>

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

Im Focus: (Re)solving the jet/cocoon riddle of a gravitational wave event

An international research team including astronomers from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has combined radio telescopes from five continents to prove the existence of a narrow stream of material, a so-called jet, emerging from the only gravitational wave event involving two neutron stars observed so far. With its high sensitivity and excellent performance, the 100-m radio telescope in Effelsberg played an important role in the observations.

In August 2017, two neutron stars were observed colliding, producing gravitational waves that were detected by the American LIGO and European Virgo detectors....

Im Focus: Light from a roll – hybrid OLED creates innovative and functional luminous surfaces

Up to now, OLEDs have been used exclusively as a novel lighting technology for use in luminaires and lamps. However, flexible organic technology can offer much more: as an active lighting surface, it can be combined with a wide variety of materials, not just to modify but to revolutionize the functionality and design of countless existing products. To exemplify this, the Fraunhofer FEP together with the company EMDE development of light GmbH will be presenting hybrid flexible OLEDs integrated into textile designs within the EU-funded project PI-SCALE for the first time at LOPEC (March 19-21, 2019 in Munich, Germany) as examples of some of the many possible applications.

The Fraunhofer FEP, a provider of research and development services in the field of organic electronics, has long been involved in the development of...

Im Focus: Regensburg physicists watch electron transfer in a single molecule

For the first time, an international team of scientists based in Regensburg, Germany, has recorded the orbitals of single molecules in different charge states in a novel type of microscopy. The research findings are published under the title “Mapping orbital changes upon electron transfer with tunneling microscopy on insulators” in the prestigious journal “Nature”.

The building blocks of matter surrounding us are atoms and molecules. The properties of that matter, however, are often not set by these building blocks...

Im Focus: University of Konstanz gains new insights into the recent development of the human immune system

Scientists at the University of Konstanz identify fierce competition between the human immune system and bacterial pathogens

Cell biologists from the University of Konstanz shed light on a recent evolutionary process in the human immune system and publish their findings in the...

Im Focus: Transformation through Light

Laser physicists have taken snapshots of carbon molecules C₆₀ showing how they transform in intense infrared light

When carbon molecules C₆₀ are exposed to an intense infrared light, they change their ball-like structure to a more elongated version. This has now been...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Global Legal Hackathon at HAW Hamburg

11.02.2019 | Event News

The world of quantum chemistry meets in Heidelberg

30.01.2019 | Event News

Our digital society in 2040

16.01.2019 | Event News

 
Latest News

JILA researchers make coldest quantum gas of molecules

22.02.2019 | Physics and Astronomy

Understanding high efficiency of deep ultraviolet LEDs

22.02.2019 | Materials Sciences

Russian scientists show changes in the erythrocyte nanostructure under stress

22.02.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>