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Buckminsterfullerene

Buckminsterfullerene Once in a while there are discoveries of compounds which surprise the scientific community. In 1985 such a discovery took place; it was the discovery of the compound named Buckminsterfullerene. The compound was the first of its kind: a big 60-atom molecule resembling a soccer ball, composed of carbon, and arranged in a perfect geodesic sphere. This compound was unique in its nature because it was the first time carbon was observed in a very stable and solid three-dimensional structure. Prior to this discovery, carbon was not thought to behave in such a manner: carbon had always been thought to be most stable when arranged in two-dimensional sheets. The discovery of this new carbon molecule created a new curiosity that still lives today. Carbon atoms form buckminsterfullerene by making hexagons and pentagons that snap together into a hollow ball. A molecule with a shape like this is sure to have interesting properties, and it does indeed. Strength, stability, superconductivity, and biological harmlessness are some of the favorites. Buckminsterfullerene first gave scientists a hint of its presence in the early 1980's when tests on carbon soot from space showed inexplicable bumps on otherwise smooth graphs. Further tests involved a machine designed to produce clusters of atoms. The results were clear: carbon had a strong tendency to aggregate in groups of 60. More tests under different conditions put carbon 60 production virtually off the chart. The prominence of clusters of 60 carbon atoms suggested that this was a particularly stable number, but the form of this molecule was a mystery. Such stability meant no dangling bonds. One possibility was that carbon's usual hexagons might have curved around to create a sort of chicken wire cage, which would eliminate dangling bonds. An architect's work gave the researchers an idea. Buckminsterfullerene molecules consist of 60 carbon atoms linked together to form an almost spherical ball with the chemical formula C60. The bonds between atoms form a pattern of joined hexagons and pentagons that is similar to the panels on a soccer ball. The allotrope was given its name because its structure resembles the elaborate geometrical structures invented by American architect Buckminster Fuller. The individual molecules have become known as buckyballs. For many years it was believed that the element carbon occurred as only three allotropes: diamond, graphite, and amorphous carbon. In each of these allotropes, the carbon atoms are linked together in a different arrangement, giving the form of the element different properties. In 1985, however, a new family of allotropes was discovered. Of these allotropes, which are called fullerenes, buckminsterfullerene has become the most famous. Other fullerenes have more carbon atoms, and their shapes resemble elongated versions of the original, soccer ball-shaped buckminsterfullerene. Once buckminsterfullerene could be produced in large amounts, a solid form, fullerite, was also produced. In this transparent yellow solid, the molecules are stacked together in a close-packed arrangement like a pile of cannon balls. Tubular versions of fullerenes are also available in solid form. Buckminsterfullerene has been a paragon of stability because of its survival skills inside the cluster-making machine where it first made itself known. Its strong bonds enable it to avoid bonding with free molecules -- an essential characteristic for ultimate stability. Add to this the fact that carbon bonding is extremely well understood and controllable, and the result is a molecule perfect for nanotechnology's task of molecular construction. The strength of buckminsterfullerene will allow materials made from it to stand up to more stress than the other carbon forms, graphite and diamond, could manage. Its spherical structure and strong carbon bonds prevent defects from spreading and affecting the overall strength of the material. High-speed collisions don't faze it, and it virtually never fragments. The original method of preparation of buckminsterfullerene was to produce it in a molecular beam, and only very small quantities could be made. However, it was soon found that the molecules were produced in large numbers in an electric arc between two carbon electrodes in a helium atmosphere. Scientists now believe that buckminsterfullerene is likely to be formed in sooty flames, and there is a possibility that it is abundant in the universe, particularly near red-giant stars. The versatility of fullerene molecules has led to a great deal of research exploring their properties. One potentially useful property is that atoms of different elements can be placed inside the molecular cage formed by the carbon atoms, producing a "shrink wrapped" version of these elements. When metal atoms are introduced into fullerene tubes, the resulting material is like a one-dimensional insulated wire. Another important property is that certain compounds of buckminsterfullerene (notably K3C60) are superconducting at low temperatures. Compounds made by adding thallium and rubidium ions (electrically charged atoms) to fullerenes become superconducting at -228° C (-378° F). This temperature is relatively high compared to the cooling required by other superconducting materials. With traits like these, buckminsterfullerene will be a key player in nanotechnology. Advances in manipulating buckminsterfullerene have already occurred. Scientists at the University of Massachusetts at Amherst have made progress with a tool for holding buckminsterfullerene. Other chemists have made a buckminsterfullerene molecule with a hole in it, which is an advance toward more controlled entrapment of other molecules within the buckminsterfullerene cage. Derivatives of buckminsterfullerene have been found to be biologically active and have been used to attack cancer. It is believed that the molecules can enter the active sites of enzymes and block their action. The carbon balls could also protect injured brain tissue by mopping up highly reactive molecules called free radicals. After head injury or a stroke, nerve cells are killed by the overproduction of oxidising free radicals in the brain. Buckyballs can be used as protection by eliminating these free radicals. Buckminsterfullerene's cage shape is also promising. The molecules can serve as tiny machines to entrap and transport other molecules. Coupled with its carbon's biological benignity, this characteristic may allow buckminsterfullerene to serve as a casing for medial materials the human body might otherwise rebel against. Organ transplants and radiation treatment could be revolutionized with buckminsterfullerene. Medical applications show additional potential because of the ease with which buckminsterfullerene retains its purity. It doesn't attract free molecules. In contrast, for example, diamond's dangling bonds mean it attracts a sheet of hydrogen with which scientists must contend. There is the speculation now that Buckyballs can be utilized as transistors for new nanocomputers, as protection for damages nerve cells, as fuel for low-power, long-life thrusters that satellites use, and as catalyst for simple organism reproduction. Without a doubt the discovery of this compound has been a blessing for the scientific community. The promises of Buckminsterfullerene are immense and its possibilities have not even been fully explored yet. Furthur tests and experiments continue to this day on how we can utilize buckyballs to aid and perform various tasks. One thing is for certain, Buckminsterfullerene holds potential for the future. Bibliography: Bibliography Discover v. 11, Sept. 1990, p. 52-9 “Fungal growth on buckminsterfullerene” Microbiology, v. 143, July 1997 p. 2097-8. “Buckyball transistor raises nanocomputing hopes”, New Scientist, v. 153, Mar. 30, 1997 p. 18. “Buckymedicine”, New Scientist, v. 155, Aug. 30, 1997 p. 18. “Buckyballs are a blast”, New Scientist, v. 156, Oct. 18, 1997 p. 23. “Materials Jamboree”, Science, v. 242, Nov. 25, 1988 p. 1139-45. “Polymer, buckyballs combat nerve damage”, Science News, v. 152, Aug. 23, 1997 p. 119. “Soccer-Ball Molecules in Space”, Sky and Telescope, v. 72, Apr. 1989 p. 358.

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