Using ecstasy to keep little bundles apart

Hollow tubes of carbon just 10 atoms across represent one of the new frontiers of physics. It is a mysterious realm, however, where the laws of nature don't quite behave as normal and where physics joins with chemistry to produce new substances with special properties.

A presentation on this land of the impossibly small provided the winning entry in the annual Science Speak competition last week at the Royal Dublin Society. The inter-varsity event involves all seven of the Republic's universities and challenges graduate students to explain their research to a lay audience using ordinary language.

The €1,000 first prize went to Trinity College Dublin's Shane Bergin, a final year PhD candidate in the school of physics. He is part of a 12-strong group led by supervisor Dr Jonathan Coleman with the unusual title, "The chemical physics of one-dimensional nanostructures".

Nanostructures are so small, 50,000 times thinner than a human hair, that they effectively become one-dimensional, explains Bergin. They have no width or depth, only a defined length.

The object of his PhD and the work he described in the competition relates to handling these one-dimensional nanostructures, carbon nanotubes. They have dozens of applications, but are problematic because they tend to "bundle together", he explains.

Groups around the world have sought to break the clumped bundles apart so individual nanotubes can be isolated. Most of the effort has involved using chemicals to permanently change the surface of the nanotubes.

This chemical alteration works, but the tubes tend to rebundle over time. Bergin began searching for chemical solvents that could help separate the bundles and keep the tubes separated permanently.

The search resulted in a surprise: a liquefied form of an illegal drug proved one of the most effective solvents. "We came up with a list of about 50 promising solvents and one of them was liquid ecstasy," he says.

The team placed bundled nanotubes into the solvent and then used high energy sound waves to agitate the mixture.

This forced the solvent down in between the tubes, separating them and disbursing them in the liquid. The mixture was diluted with solvent and the process repeated several times, and the team was able to confirm they had successfully debundled the nanotubes.

Importantly, they found that the separated tubes didn't rebundle, they remained separated and could be manipulated individually. "The solvent prevents the nanotubes from rebundling. The solvent doesn't form covalent bonds with the carbon, it is associated with the carbon but without bonding to it."

Second place in the competition went to University College Cork's Dawn Griffin who received a gift voucher of €300. A €200 gift voucher for third place went to Elaine McSherry of University College Dublin. €100 vouchers went to the four runners-up, Norah Nelson of Dublin City University, Sandra Galvin of NUI Galway, Ciaran Skerry of NUI Maynooth and Barry Fitzgerald of the University of Limerick.

Science Speak is a joint initiative by the RDS and The Irish Timesin association with Irish Universities Promoting Science. It is also sponsored by the Discover Science and Engineering programme and by Wyeth Biotech, Grange Castle.

Judging panel chairman Peter Brabazon announced that Wyeth had agreed to continue sponsoring Science Speak for at least another three years.

Correction:Last week's report on the Greenwave Project carried an incorrect spelling of the name of the author, Ronan McGreevy