Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Diamonds, nanotubes find common ground in graphene

29.05.2013
Hybrid created by Rice, Honda Research Institute shows nanotubes can grow on anything
What may be the ultimate heat sink is only possible because of yet another astounding capability of graphene. The one-atom-thick form of carbon can act as a go-between that allows vertically aligned carbon nanotubes to grow on nearly anything.

That includes diamonds. A diamond film/graphene/nanotube structure was one result of new research carried out by scientists at Rice University and the Honda Research Institute USA, reported today in Nature’s online journal Scientific Reports.

The heart of the research is the revelation that when graphene is used as a middleman, surfaces considered unusable as substrates for carbon nanotube growth now have the potential to do so. Diamond happens to be a good example, according to Rice materials scientist Pulickel Ajayan and Honda chief scientist Avetik Harutyunyan.

Diamond conducts heat very well, five times better than copper. But its available surface area is very low. By its very nature, one-atom-thick graphene is all surface area. The same could be said of carbon nanotubes, which are basically rolled-up tubes of graphene. A vertically aligned forest of carbon nanotubes grown on diamond would disperse heat like a traditional heat sink, but with millions of fins. Such an ultrathin array could save space in small microprocessor-based devices.

“Further work along these lines could produce such structures as patterned nanotube arrays on diamond that could be utilized in electronic devices,” Ajayan said. Graphene and metallic nanotubes are also highly conductive; in combination with metallic substrates, they may also have uses in advanced electronics, he said.

To test their ideas, the Honda team grew various types of graphene on copper foil by standard chemical vapor deposition. They then transferred the tiny graphene sheets to diamond, quartz and other metals for further study by the Rice team.

They found that only single-layer graphene worked well, and sheets with ripples or wrinkles worked best. The defects appeared to capture and hold the airborne iron-based catalyst particles from which the nanotubes grow. The researchers think graphene facilitates nanotube growth by keeping the catalyst particles from clumping.

Ajayan thinks the extreme thinness of graphene does the trick. In a previous study, the Rice lab found graphene shows materials coated with graphene can get wet, but the graphene provides protection against oxidation. “That might be one of the big things about graphene, that you can have a noninvasive coating that keeps the property of the substrate but adds value,” he said. “Here it allows the catalytic activity but stops the catalyst from aggregating.”

Testing found that the graphene layer remains intact between the nanotube forest and the diamond or other substrate. On a metallic substrate like copper, the entire hybrid is highly conductive.

Such seamless integration through the graphene interface would provide low-contact resistance between current collectors and the active materials of electrochemical cells, a remarkable step toward building high-power energy devices, said Rice research scientist and co-author Leela Mohana Reddy Arava.

Co-authors of the study are Honda senior scientists Rahul Rao and Gugang Chen; Rice graduate student Kaushik Kalaga; Masahiro Ishigami, an assistant professor of physics at the University of Central Florida; and Tony Heinz, the D.M. Rickey Professor of Physics at Columbia University. Ajayan is the Benjamin M. and Mary Greenwood Anderson Professor in Mechanical Engineering and Materials Science and of chemistry at Rice.

The research was supported by the Honda Research Institute.


Read the open-access paper at http://www.nature.com/srep/2013/130528/srep01891/full/srep01891.html

Follow Rice News and Media Relations via Twitter @RiceUNews

Related Materials:
Ajayan Group: http://www.owlnet.rice.edu/~rv4/Ajayan/
Honda Research Institute: http://www.honda-ri.com

David Ruth | EurekAlert!
Further information:
http://www.rice.edu
http://news.rice.edu/2013/05/28/diamonds-nanotubes-find-common-ground-in-graphene/

More articles from Physics and Astronomy:

nachricht New NASA study improves search for habitable worlds
20.10.2017 | NASA/Goddard Space Flight Center

nachricht Physics boosts artificial intelligence methods
19.10.2017 | California Institute of Technology

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>