Researchers at Rice University (where fullerene was first discovered) have successfully created flat graphene nanoribbons by unzipping carbon nanotubes. The nanotubes were exposed to sulfuric acid and a strong oxidizing agent. This reaction breaks a single carbon-carbon bond, and two oxygen atoms are bound to the two carbon atoms. The oxygen atoms cause strain on the adjacent carbon-carbon bond, and this strain results in unzipping.
The process is carried out at room temperature and makes it possible to produce graphene nanoribbons in bulk quantities. Therefore, this technique is of great interest to electronics manufactures, since graphene transistors perform better than those made of silicon.
This method and another method developed at Stanford University for producing nanoribbions are featured in the current issue of Nature (Vol. 458 Number 7240).
MIT Technology Review
Nature current issue cover
Chemical and Engineering News
e! Science News
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To follow up on what Max wrote, the process developed at Stanford University is useful for unzipping both multi-walled and single-walled tubes. In contrast, the technique Max described has presented some problems with single-walled tubes, causing tangling of the ribbons.
The Stanford technique involves embedding the graphene tubes in a polymer film and etching them with an argon plasma. The polymer film is then removed with heat and a solvent vapor. These ribbons range from 10 to 20 nm in width.
For more information, see the articles Max quoted. I used the C&EN article at http://pubs.acs.org/cen/news/87/i16/8716notw4.html as a source for this response.
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