Sixty atoms, in a geodesic dome
Last updated: 06 December, 2010
Radhakrishna Rao 18:46 IST
Carbon nanotubes, the discovery of which has been traced to a seminal 1991 paper authored by Sumio lijima of Japan’s NEC Corporation, are today the most attractive and exciting face of nanotechnology.
Carbon nanotubes contribute to the radical advances in the areas of electronics, energy, medicine and materials. Indeed, a range of exciting applications proposed for high-strength carbon nanotubes include high performance composites, energy storage and energy conversion devices, sensors, field emission displays and radiation sources, hydrogen storage systems as well nanometre-sized semiconductor devices and probes. Known for their phenomenal tensile strength, carbon nanotubes can act as a conductor or a semiconductor depending upon the arrangement of carbon atoms. Researchers have now devised simpler and easier techniques to engineer carbon nanotubes by triggering an electric arc between two graphite electrodes or passing hydrocarbon gas over a metal catalyst.
It was an epochal research breakthrough reported in 1985 that ultimately paved the way for the evolution of carbon nanotubes. In an experiment spearheaded by a team of researchers at Rice University, a form of solid carbon, totally different and distinct from diamond and graphite was discovered. In this innovative study, which was described as the future of technology, a graphite sample was subjected to jet laser spectroscopy which helped researchers record an abundance of carbon clusters, each of which contained sixty atoms. But what confounded the researchers was the uniqueness of mechanism which helped these sixty atoms to remain in a totally stable configuration.
Subsequent probing went on to show that one carbon atom lies at each vertex of 12 pentagons and 20 hexagons arranged into a structure that looked similar to a soccer ball.
What gave buckyballs their name?
The carbon molecule made up of 60 atoms arranged in a series of interlocking hexagons and pentagons came to be named “buckminsterfullerene” after R Buckminister Fuller, the celebrated American architect who designed a geodesic dome with the same fundamental symmetry. Interestingly, buckyball has been described as the rounder and most symmetrical large molecule ever discovered by man. Being the roundest of round molecules, the buckyball is quite resistant to high speed collisions. In fact, the buckyball can withstand slamming into a stainless steel plate at 15,000mph, merely bouncing back unharmed. When compressed to 70% of its original size, the buckyball becomes more than twice as hard as diamond. It is these unique qualities that makes development of carbon nanotubes that are stronger than steel possible.