Unzipping Carbon Nanotubes Can Make Graphene Ribbons

April 20, 2009 by Lisa Zyga weblog
unzipping nanotubes
By "unzipping" carbon nanotubes, researchers can make graphene ribbons. Image credit: Liying Jiao, Li Zhang and Hongjie Dai.

(PhysOrg.com) -- By "unzipping" carbon nanotubes, researchers have shown how to make flat graphene ribbons. Graphene, which is a one-atom-thick sheet of carbon that looks like chicken wire, has unique electrical properties that could have many future electronics applications. However, one of the biggest challenges researchers currently face is producing graphene in large quantities.

Recently, two research groups have demonstrated that unzipping carbon nanotubes can produce graphene ribbons in a variety of widths.

In the first group, scientists at Rice University in Houston led by James Tour used sulphuric acid and an oxidizing agent to chemically create a hole in the carbon nanotubes. The hole expanded along the side of the nanotube, unzipping the tube to form a flat graphene ribbon. The width of the graphene ribbon depended on the diameter of the nanotubes. In their experiments, the researchers used multiwalled nanotubes with diameters ranging from 40 to 80 nanometers, resulting in ribbons with widths from 100 to 250 nanometers, and about 4 micrometers long.

The researchers suggest that this type of graphene ribbon could be used for conductive or semiconducting thin films, and possibly as an inexpensive substitute for monocrystalline silicon in photovoltaics. However, the method makes it difficult to accurately place a single ribbon on a substrate, which will make it challenging to fabricate many devices.

The second group, which consisted of Stanford researchers led by Hongiie Dai, tried a different approach. They placed nanotubes on a , coated them with a polymer, and baked them. Then they peeled off the polymer, which the nanotubes were embedded in. Exposing this polymer-nanotube material to a 10-watt argon plasma for 10 seconds cut some of the exposed nanotubes into graphene ribbons. Longer exposures could cut nanotubes that were further embedded in the polymer. After dissolving the polymer, only the graphene ribbons remained. This baking and cutting method produced graphene ribbons with relatively clean edges and few defects, which optimizes their conductive properties.

While both methods provide new ways of producing graphene, more work needs to be done to achieve better control of the widths, edges, and uniformity. Finding a practical way to form graphene is necessary for many future applications, including high-speed transistors, sensors, and even scaffolding for tissue regeneration.

© 2009 PhysOrg.com

Explore further: AMO Manufactures First Graphene Transistors

Related Stories

AMO Manufactures First Graphene Transistors

February 8, 2007

In the scope of his innovative project ALEGRA the AMO nanoelectronics group of Dr. Max Lemme was able to manufacture top-gated transistor-like field-effect devices from monolayer graphene.

Rice researchers unzip the future

April 15, 2009

Scientists at Rice University have found a simple way to create basic elements for aircraft, flat-screen TVs, electronics and other products that incorporate sheets of tough, electrically conductive material.

Recommended for you

An engineered surface unsticks sticky water droplets

August 31, 2015

The leaves of the lotus flower, and other natural surfaces that repel water and dirt, have been the model for many types of engineered liquid-repelling surfaces. As slippery as these surfaces are, however, tiny water droplets ...

Electrical circuit made of gel can repair itself

August 25, 2015

(Phys.org)—Scientists have fabricated a flexible electrical circuit that, when cut into two pieces, can repair itself and fully restore its original conductivity. The circuit is made of a new gel that possesses a combination ...

3 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

NeilFarbstein
1 / 5 (1) Apr 20, 2009
What's wrong with hummer's method?????
Fazer
not rated yet Apr 26, 2009
Considering 'Carbon' seems like such a bad word these days, I find it ironic that, after reading the constant barage of nanotube articles that pour out of the research labs of the world, it seems as though in the future we will be litterally BATHING in carbon nanotubes and their derivatives: we'll have them in our bones, on our teeth, in our hair, in our clothes, we'll build composite materials with them, electronics, solar panels, space elevators, and who knows, maybe, one day, we'll even eat them!

"Carbon Nanotubes are People!"
NeilFarbstein
2.3 / 5 (3) Apr 29, 2009
Buckyfood for buckypeople!!!!

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.