Monday, February 2, 2015

The Future Of Graphene

Material Science




There is a long distance between discovery and application, between research and putting a material to profitable and continuous use. This is now the case with graphene, an article, by John Colapinto, in The New Yorker says. It traces the initial discovery, more than a decade ago, of Andre Konstantin Geim, a physicist at the University of Manchester, who was able to isolate single atoms of carbon, called graphene.

Colapinto writes:
On one such evening, in the fall of 2002, Geim was thinking about carbon. He specializes in microscopically thin materials, and he wondered how very thin layers of carbon might behave under certain experimental conditions. Graphite, which consists of stacks of atom-thick carbon layers, was an obvious material to work with, but the standard methods for isolating superthin samples would overheat the material, destroying it. So Geim had set one of his new Ph.D. students, Da Jiang, the task of trying to obtain as thin a sample as possible—perhaps a few hundred atomic layers—by polishing a one-inch graphite crystal. Several weeks later, Jiang delivered a speck of carbon in a petri dish. After looking at it under a microscope, Geim recalls, he asked him to try again; Jiang admitted that this was all that was left of the crystal. As Geim teasingly admonished him (“You polished a mountain to get a grain of sand?”), one of his senior fellows glanced at a ball of used Scotch tape in the wastebasket, its sticky side covered with a gray, slightly shiny film of graphite residue.
It would have been a familiar sight in labs around the world, where researchers routinely use tape to test the adhesive properties of experimental samples. The layers of carbon that make up graphite are weakly bonded (hence its adoption, in 1564, for pencils, which shed a visible trace when dragged across paper), so tape removes flakes of it readily. Geim placed a piece of the tape under the microscope and discovered that the graphite layers were thinner than any others he’d seen. By folding the tape, pressing the residue together and pulling it apart, he was able to peel the flakes down to still thinner layers.
Geim had isolated the first two-dimensional material ever discovered: an atom-thick layer of carbon, which appeared, under an atomic microscope, as a flat lattice of hexagons linked in a honeycomb pattern. Theoretical physicists had speculated about such a substance, calling it “graphene,” but had assumed that a single atomic layer could not be obtained at room temperature—that it would pull apart into microscopic balls. Instead, Geim saw, graphene remained in a single plane, developing ripples as the material stabilized.
Geim and Konstantin Novoselov won the Nobel Prize in Physics, in 2010, for this discovery. And, as is often the case with such discoveries, people were looking at ways to monetize it.
By then, the media were calling graphene “a wonder material,” a substance that, as the Guardian put it, “could change the world.” Academic researchers in physics, electrical engineering, medicine, chemistry, and other fields flocked to graphene, as did scientists at top electronics firms.
So far, graphene, as wondrous as it is, has eluded the best minds to put it to practical use. This does not in any way suggest that graphene can’t be put to practical use, but, rather, that the way to do so economically and easily has not yet been discovered. 

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For more, go to [NewYorker]

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