12.03.12

Lasting Gifts From Carbon Connections

Scientists at Oak Ridge National Laboratory open new views of graphene, which may help unlock its potential for a vast range of products.

Everyone has a favorite holiday treat. But what truly makes the season special isn't the tastes or the songs or the scents . . . it's the presents.

Actually, it's the gatherings with family and friends, the reconnecting and re-bonding. What's true for people is true for particles too, since the bonds between the elements play a critical part in shaping much of the stuff that puts smiles in our lives.

Click to enlarge photo. Enlarge Photo

Two images of silicon atoms Image courtesy of Oak Ridge National Laboratory

The atomic resolution Z-contrast images show individual silicon atoms bonded differently in graphene.

Recently, a group of researchers at the Office of Science's Oak Ridge National Laboratory (ORNL) led by Dr. Juan-Carlos Idrobo took a detailed look at how atoms connect in a remarkable material called graphene, which may unlock its potential for a wide range of uses. Graphene, which was discovered a few years ago, consists of single layers of the element carbon connected together in flat, honeycomb-like structures. The layers are almost two-dimensional – just one atom deep – but their structure produces a substance with striking properties. Graphene crystals are harder than diamond and stronger than steel, yet the material is also stretchable and almost transparent, and is a better electrical conductor than copper.

As a consequence, scientists supported by the Office of Science are striving to better understand how graphene works so they can unlock its full potential. That's where Dr. Idrobo and his team came in. In research that was also supported by the National Science Foundation, they used a sophisticated and sensitive (yes, that sounds like the person you're trying to set your single friend up with) scanning transmission electron microscope to provide previously unseen views of how individual carbon atoms connect to one another in graphene, as well as how they connect to atoms of other elements. This microscope is part of ORNL's Shared Research Equipment User Program Facility supported by the DOE Office of Science.

Those insights are important, since carbon is nature's essential connector: In addition to being the stuff of graphene and diamond and pencil ‘lead,' carbon also forms the backbone of living things like plants and people. The differences come in how the carbon atoms are connected, and to what other atoms they're connected. Moreover, different atomic connections – different chemical bonds – can alter the architecture of a material, which can have a further impact on its properties.

Click to enlarge photo. Enlarge Photo

An image of silicon atoms Image courtesy of Oak Ridge National Laboratory

The atomic resolution Z-contrast image shows individual silicon atoms bonded differently in graphene.

So by better understanding the shape of those bonds, researchers can see a way to predicting, and perhaps even designing graphene-based materials with a variety of different and desired properties. For instance, they might someday be able to plug in atoms of other elements – say, silicon or iron or copper – to make a material difference in the performance of new materials. And those materials might lead to a vast range of new products, such as better catalytic converters in cars, or better digital displays in TVs and cell phones and other hand-held electronics.

So perhaps someday, in the not too distant future, a holiday will be even memorable thanks to the rekindling of connections between old family and friends . . . and the new and even better presents that came from the Office of Science and its research on graphene.

The Department's Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information please visit http://science.energy.gov/about. For more information about Oak Ridge National Laboratory, please go to http://www.ornl.gov/External link.

Charles Rousseaux is a Senior Writer in the Office of Science.

Last modified: 5/30/2013 11:33:44 AM