1.1 Buckyballs: their history and discovery  (Page 5/6)

An interesting feature of Fullerenes is that their hollow structure allows them to hold other atoms inside them.The applications of this are abound, and are being studied to great extent.

Important to note about any new material is its health concerns. Although believed to be relatively inert,experiments by Eva Oberdörster at Southern Methodist University, presented some possible dangers of fullerenes. She introducedbuckyballs into water at concentrations of 0.5 parts per million, and found that largemouth bass suffered a 17-fold increase incellular damage in the brain tissue after 48 hours. The damage was of the type lipid peroxidation, which is known to impair thefunctioning of cell membranes. Their livers were also inflamed and genes responsible for producing repair enzymes were activated. Asof 10/20/05, the SMU work had not been peer reviewed.

What have buckyballs contributed to science?

After the astrophysicists D.R. Huffmann and W. Kratschmer managed to produce larger quantities of fullerenes in1990, scientists further investigated the structure and characteristics of buckyballs. Research on buckyballs has led tothe synthesis of over 1000 new compounds with exciting properties, and over 100 patents related to buckyballs have been filed in theUS. In addition, an important new material, nanotubes, has exploded onto the scientific scene in recent years. The discovery andmanufacture of nanotubes resulted directly from research on buckyballs. Finally, although buckyballs have not yet been used inany practical applications, partly due to the high cost of material, researchers are using buckyballs to learn more about thehistory of our world, and companies are devising some interesting uses for buckyballs even today.

Nanotubes

The discovery of nanotubes in 1991 by S. Iijima has been by far the buckyball’s most significant contribution to currentresearch. Nanotubes, both single- and multi-walled, can be thought of as sheets of graphite rolled into cylinders and sometimes cappedwith half-fullerenes. Nanotubes, like fullerenes, possess some very unique properties, such as high electrical and thermalconductivity, high mechanical strength, and high surface area. In fact, carbon nanotubes provide a clear example of the specialproperties inherent at the quantum level because they can act as either semi-conductors or metals, unlike macroscopic quantities ofcarbon molecules. These properties make nanotubes extremely interesting to researchers and companies, who are alreadydeveloping many potentially revolutionary uses for them.

What are buckyballs teaching us about our world?

A paper published on March 28, 2000 in the Proceedings of the National Academy ofSciences (PNAS) by Becker, Poreda, and Bunch uses buckyballs to provide new evidence for early periods in earth’s geological andbiological history. By exploiting the unique properties of buckyballs, these three scientists were able to study geology in anew way. First of all, the unique ability to extract fullerenes (unlike graphite and diamond) from organic solvents allowed them toisolate carbon material in the meteorites, then the unique cage-like structure of fullerenes allowed them to investigate thenoble gases enclosed within the ancient fullerenes. In their study, the researches found helium of extraterrestrial origin trappedinside buckyballs extracted from two meteorites and sedimentary clay layers from 2 billion and 65 million years ago respectively.The helium inside these buckyballs bears unusual ratios of 3He/4He coupled with non-atmospheric ratios of 40Ar/36Ar, which accordingto their research indicates extraterrestrial origin. In addition, they have shown that these fullerenes could not have been formedupon impact of the meteorite or during subsequent forest fires.iBecker, Poreda, and Bunch. 2982.