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The Longest Now


On Graphene
Sunday December 26th 2010, 12:16 am
Filed under: chain-gang,Glory, glory, glory,Too weird for fiction

Graphene is one of the most remarkable substances in the world. Physicists Andre Geim and Konstantin Novoselov won the Nobel Prize for their work to manufacture single-layer sheets of it only six years after their first success.

Now it is entering mass production, and being considered for the sort of applications that currently rely on nanotubes. It might also be suitable for very different macro-scale tasks, as sheets of graphene can theoretically be arbitrarily broad (while just one atom thick), once a suitable production process is worked out.

In practice, it is still hard to produce monolayer sheets of graphene, but we are making thinner and thinner ‘platelets’ by exfoliating them from larger chunks. Many current applications depend on the bulk surface area available for interaction with the environment, and platelets are often marketed in terms of their surface area per unit weight (in m^2/g).

The properties of commercially produced graphene are 1-2 magnitudes less than the extreme values measurable with pure monolayer sheets. So on top of the practical economic applications today, there is a decade of Moore-like improvement to look forward to. Costs of production vary according to purity: low-grade graphene (platelets 3-10 layers thick and a few dozen microns wide) are available for under $300/kg, while higher-quality graphene (1-3 layers thick, hundreds of microns wide) can range from $10/gram to $100/gram, and only in small quantities.

Finally, my favorite factoid about graphene (out of MANY): you can use a sheet of it to directly measure the fine structure constant: each layer absorbs πα (that’s pi times the fine structure constant) of light that passes through it!




also one of my favorite stock topics for teaching engineers how to search the research literature 🙂

Comment by phoebe 12.26.10 @ 1:33 pm





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