Last week the Nobel committee announced that they were going to award the Nobel Prize in Physics to Andre Geim and Konstantin Novoselov for “groundbreaking experiments regarding the two-dimensional material graphene.” It awoke my interest for two reasons, i) because the it’s regarding physics and ii) because part of the research was performed in the Netherlands. But what is graphene? And why is it interesting? I would very much like to take this opportunity to try and explain.
Graphene is quite directly linked to graphite, the stuff that’s in your pencils, the only difference is that the atomic structure of the latter is stacked and that the structure of the prior consists of just a single layer. The rest of the structure is the same, both consist of hexagonal shapes like in chicken fence. It’s also similar to diamond which has fascinated people for centuries because of its extreme hardness.
Atomic Structure of Graphene
This property finds its cause in the atomic structure which I’d like to elaborate on now for a bit. All the materials I’ve talked about so far consist of carbon atoms, nothing more, nothing less. The only difference is the way they’re connected. In diamond, for instance, each carbon atom has got four neighbors. This is what carbon likes best, it’s like a party where everyone has got four arms that they bend in order to chain up with other party-goers. This chaining up unfortunately only happens under rare circumstances like extreme pressure and heat, in the natural world only present underneath and in the Earth’s crust.
On top of the planet, however, the party-goers are only able to chain up with three friends. Leading to the formation of graphite, naturally, in a chicken fence (hexagonal shaped) lattice. This may sound like a big bummer but it’s not. The weak interactions between the different layers create possibilities such as writing with pencil and graphene.
Graphene really has got some stunning properties. I guess most people haven’t tried, and never will themselves be in a position to do so, but diamond doesn’t conduct electricity; graphene does. You can grab a pencil, draw a line on a piece of paper, connect one end with some power supply and the other end with a light bulb and it will work. This conductance is really good, it’s one of the best conducting materials known.
And now we’re gonna have to get a bit technical. The reason graphene is such a superb conductor is that each atom has got a spare arm that isn’t hooked up to another one. When a flow of electricity is applied, electrons (or – and excuse me for this little morbidity – limbs, if you wish) start traveling through the structure. Every atom uses it’s spare arm to hook on to the stream of other arms and give it an extra push from A to B. Because graphene is so regular this happens extremely fast, much, much faster than in most materials.
By means of a bonus this single layer of atoms is strong, not a surprise if you realize it’s a cousin of diamond, which enables applications! Fabulous applications, such as in computer hardware. Right now silicon is used for this purpose (hence ‘Silicon Valley’) but graphene is about one hundred times faster in conducting electric flow than silicon. And since computing is nothing but conducting and redirecting electric flow there’s definitely some future for this material.
Well, that is, in a very abbreviated sense, what all the graphene-buzz is about. I hope you understand this interesting field in material sciences a little better now, and if you have any questions left I’d love to hear them; either in the comments of via e-mail at our correspondence address: contact@superforest.org.
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