Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers Develop New Method for Mass-Producing Graphene

23.06.2010
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, available at http://pubs.acs.org/doi/abs/10.1021/nl903557p, 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 doctoral student 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

Contact
Michael Mullaney
Rensselaer Polytechnic Institute
Troy, NY
518-276-6161 (office)
518-698-6336 (mobile)
mullam@rpi.edu

Michael Mullaney | Newswise Science News
Further information:
http://www.rpi.edu

More articles from Materials Sciences:

nachricht Meter-sized single-crystal graphene growth becomes possible
22.08.2017 | Science China Press

nachricht Nagoya physicists resolve long-standing mystery of structure-less transition
21.08.2017 | Nagoya University

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

Cholesterol-lowering drugs may fight infectious disease

22.08.2017 | Health and Medicine

Meter-sized single-crystal graphene growth becomes possible

22.08.2017 | Materials Sciences

Repairing damaged hearts with self-healing heart cells

22.08.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>