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Graphene - the new wonder material
Scientific interest rolls in for a material that is more solid than steel and a better conductor than copper
The Guardian Weekly
David Larousserie
11/22/2013
Excerpt:
The molecule is priceless but it is not a matter of cost – a few hundred dollars per kilo. The value lies in its potential. The molecule in question is called graphene and the EU is prepared to devote €1bn ($1.3bn) to it between 2013 and 2023 to find out if it can transform a range of sectors such as electronics, energy, health and construction. According to Scopus, the bibliographic database, more than 8,000 papers have been written about graphene since 2005.
As its name indicates, graphene is extracted from graphite, the material used in pencils. Like graphite, graphene is entirely composed of carbon atoms and 1mm of graphite contains some 3 million layers of graphene. Whereas graphite is a three-dimensional crystalline arrangement, graphene is a two-dimensional crystal only an atom thick. The carbons are perfectly distributed in a hexagonal honeycomb formation only 0.3 nanometres thick, with just 0.1 nanometres between each atom.
This 100% pure carbon simplicity confers some remarkable properties on graphene, very close to the calculated theoretical ones, as observed by the authors of A Roadmap for Graphene published in Nature last year.
Graphene conducts electricity better than copper. It is 200 times stronger than steel but six times lighter. It is almost perfectly transparent since it only absorbs 2% of light. It impermeable to gases, even those as light as hydrogen or helium, and, if that were not enough, chemical components can be added to its surface to alter its properties.
"Graphene is a platform, like a chessboard, on to which one can place the pawns you want. The subtlety lies in finding the right positions. There is a real beauty in its simplicity," explained Vincent Bouchiat, from the Institut Néel in Grenoble, part of the National Centre for Scientific Research (CNRS). "The future lies in pencil graphite!" said Annick Loiseau, from the National Office for Aerospace Studies and Research (ONERA), coining a slogan. She is the French representative to the executive office of Graphene Flagship, a research consortium funded by the EU for the next 10 years.
The project was officially launched last month. "We have already learnt a great deal but new results could emerge in certain situations – only we don't yet know which ones," said Mark Goerbig, another CNRS researcher, who works in the solid physics department at Paris-Sud Orsay University.
This miracle material has come a long way. In theory, such a two-dimensional structure was believed to be unstable and therefore better rolled up, as observed in the 1990s with carbon nanotubes.
In 2004 two Russian-born scientists, Andre Geim and Konstantin Novoselov, along with others, published the first electronic measurements proving they had isolated graphene. They had removed carbon flakes from graphite using bits of sticky tape – which ultimately led to them winning a Nobel prize for physics in 2010.
"The theory only really held true for two dimensions, but in actual fact the crystal grows in a three-dimensional space and the small surface fluctuations, like waves, stabilise the crystal," said Goerbig. Experiments rapidly confirmed the marvellous behaviour of this new material, which can be explained by a kind of sea of electrons on the surface that nothing can stop and that do not interact with each other. It's as though the electrons have no mass and move at a speed 300 times slower than light. The mathematical equation to describe them is closer to that for high-energy particles than for solid matter, hence this outstanding performance that suggests so many potential uses.
Being transparent as well as a good conductor, graphene could replace the electrodes in the indium used in touchscreens. Since it is light, graphene could be integrated into composite materials to eliminate the impact of lightning on aircraft fuselages. It is also waterproof and would be perfect to use in hydrogen reservoirs.
...............................................
View the complete article at:
http://www.theguardian.com/science/2...onder-material
Scientific interest rolls in for a material that is more solid than steel and a better conductor than copper
The Guardian Weekly
David Larousserie
11/22/2013
Excerpt:
The molecule is priceless but it is not a matter of cost – a few hundred dollars per kilo. The value lies in its potential. The molecule in question is called graphene and the EU is prepared to devote €1bn ($1.3bn) to it between 2013 and 2023 to find out if it can transform a range of sectors such as electronics, energy, health and construction. According to Scopus, the bibliographic database, more than 8,000 papers have been written about graphene since 2005.
As its name indicates, graphene is extracted from graphite, the material used in pencils. Like graphite, graphene is entirely composed of carbon atoms and 1mm of graphite contains some 3 million layers of graphene. Whereas graphite is a three-dimensional crystalline arrangement, graphene is a two-dimensional crystal only an atom thick. The carbons are perfectly distributed in a hexagonal honeycomb formation only 0.3 nanometres thick, with just 0.1 nanometres between each atom.
This 100% pure carbon simplicity confers some remarkable properties on graphene, very close to the calculated theoretical ones, as observed by the authors of A Roadmap for Graphene published in Nature last year.
Graphene conducts electricity better than copper. It is 200 times stronger than steel but six times lighter. It is almost perfectly transparent since it only absorbs 2% of light. It impermeable to gases, even those as light as hydrogen or helium, and, if that were not enough, chemical components can be added to its surface to alter its properties.
"Graphene is a platform, like a chessboard, on to which one can place the pawns you want. The subtlety lies in finding the right positions. There is a real beauty in its simplicity," explained Vincent Bouchiat, from the Institut Néel in Grenoble, part of the National Centre for Scientific Research (CNRS). "The future lies in pencil graphite!" said Annick Loiseau, from the National Office for Aerospace Studies and Research (ONERA), coining a slogan. She is the French representative to the executive office of Graphene Flagship, a research consortium funded by the EU for the next 10 years.
The project was officially launched last month. "We have already learnt a great deal but new results could emerge in certain situations – only we don't yet know which ones," said Mark Goerbig, another CNRS researcher, who works in the solid physics department at Paris-Sud Orsay University.
This miracle material has come a long way. In theory, such a two-dimensional structure was believed to be unstable and therefore better rolled up, as observed in the 1990s with carbon nanotubes.
In 2004 two Russian-born scientists, Andre Geim and Konstantin Novoselov, along with others, published the first electronic measurements proving they had isolated graphene. They had removed carbon flakes from graphite using bits of sticky tape – which ultimately led to them winning a Nobel prize for physics in 2010.
"The theory only really held true for two dimensions, but in actual fact the crystal grows in a three-dimensional space and the small surface fluctuations, like waves, stabilise the crystal," said Goerbig. Experiments rapidly confirmed the marvellous behaviour of this new material, which can be explained by a kind of sea of electrons on the surface that nothing can stop and that do not interact with each other. It's as though the electrons have no mass and move at a speed 300 times slower than light. The mathematical equation to describe them is closer to that for high-energy particles than for solid matter, hence this outstanding performance that suggests so many potential uses.
Being transparent as well as a good conductor, graphene could replace the electrodes in the indium used in touchscreens. Since it is light, graphene could be integrated into composite materials to eliminate the impact of lightning on aircraft fuselages. It is also waterproof and would be perfect to use in hydrogen reservoirs.
...............................................
View the complete article at:
http://www.theguardian.com/science/2...onder-material
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