Fullerene
Fullerenes are unique carbon molecules that were discovered in the 1980s and are characterized by their hollow, spherical shape. Often likened to small soccer balls, these molecules can occur naturally or be synthesized in laboratories. Their discovery stemmed from research into long carbon chains, leading to the identification of the stable C60 molecule, also known as Buckminsterfullerene, named after architect Richard Buckminster Fuller due to its geodesic structure. Fullerenes exhibit remarkable strength and resilience, capable of withstanding extreme pressures and impacts, making them valuable in various applications.
Their potential uses span multiple fields, including nanotechnology, medicine, and electrical engineering. For instance, fullerenes could serve in drug delivery systems, enhancing the effectiveness of treatments for conditions such as AIDS and infections. Moreover, they hold promise for advancements in energy storage, environmental applications, and the development of new materials, including strong, lightweight armor. Researchers continue to explore the various compounds related to fullerenes, such as carbon nanotubes, further expanding their implications across science and technology.
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Fullerene
Fullerenes are molecules made completely of carbon. They were discovered in the 1980s by scientists investigating particles found in space. Resembling very small soccer balls in shape, fullerenes are hollow. They occur naturally and can be manufactured. Their unique properties mean that fullerenes have applications in nanotechnology, where tiny particles of matter are manipulated to achieve a specific purpose. Fullerenes have many potential uses in medicine, electrical engineering, and military technology.
Background
Carbon is a very prevalent and versatile element. About one-fifth of the human body includes carbon atoms. It is present in everyday items such as the graphite in pencils and the gasoline in cars. These different forms have different structural compositions that help determine each one's strength and purpose. For example, each carbon atom in a diamond bonds with four additional carbon atoms, making three-dimensional bonds that are hard to break. Each carbon atom in graphite is only bonded in two-dimensional layers that allow them to separate easily.
In 1985 scientists Richard Smalley, Harry Kroto, and Robert Curl began investigating the structure of long snake-like carbon molecules that Kroto thought might have originated in the atmospheres of red giant stars. Smalley had a special laser-supersonic cluster beam device known as the AP2, or the "app-two," in his laboratory at Rice University. Kroto wanted to use this to test the carbon molecules. The three men, along with three graduate students, soon began tests. Over the course of ten days, they were able to replicate the molecules Kroto was looking for. The experiments also revealed an additional never-before-seen carbon molecule.
The newly discovered C60 molecule had sixty carbon atoms and was very stable. It did not react with other elements, which puzzled the researchers. Carbon molecules usually have leftover atoms that "dangle" and react with other molecules. The fact that these new molecules did not do this left the scientists wondering about its shape. None of the shapes they considered would give the stability the molecule displayed with no leftover molecules.
One of them—even the scientists differ on who came up with the idea first—suggested that the molecule might be hollow, with its atoms arranged to form an outer skin like as a hollow sphere. As they considered the idea of a sphere, they tried forming replicas of the image in computer programs and with paper and tape using hexagons, but they discovered that the sphere would not close. Eventually, Kroto thought about geodesic domes, architectural structures that use pentagons and hexagons in combination to form a closed sphere. Smalley then constructed a paper model with sixty flat surfaces, or vertices, that formed a perfect sphere. It also closely resembled a soccer ball.
This, the scientists decided, was the way the new carbon molecule had to be shaped. They named the C60 molecule the Buckminsterfullerene after Richard Buckminster "Bucky" Fuller. Fuller was an American architect who designed a number of geodesic domes. The new molecule was also sometimes referred to as a "buckyball."
The team continued to gather information to support their idea about the shape of the C60 molecule. Other scientists duplicated the process of synthesizing C60 in multiple labs and confirmed the original hypothesis about its shape. In 1996, Smalley, Kroto, and Curl were awarded the Nobel Prize in Chemistry for their work.
Overview
Since their discovery, fullerenes have also been found in soot, especially soot created by flames from burning a combination of acetylene and benzene. They can also be reliably replicated by the Krätschmer-Huffman method. This method, named after Wolfgang Krätschmer and Donald Huffman, two of the scientists who corroborated the shape of the fullerene, involves heating carbon rods in a helium-rich atmosphere to generate fullerene-rich soot. Further testing has revealed that fullerenes are extremely strong and resilient, able to withstand the pressure of as many as three thousand atmospheres and the force of a fifteen thousand mile-per-hour collision and return to their original shape.
As a result of these properties, fullerenes show great promise for use in industrial settings as part of molecular wires for very small computers, in certain kinds of sensors, and as part of a hydrogen gas storage system. Researchers believe that fullerenes could be used to make an organic energy storage film with many possible applications, including creating such things as an outer coating that would make cell phones self-charging and advertising signs that would light without external power. The strength and resilience of the molecule could result in uses for military armor. It is also thought that fullerenes could give companies that manufacture diamonds a head start on recreating the natural process of diamond formation.
Fullerenes are already at use in some cosmetics that deliver antioxidants. It is thought that methods could someday be devised to use hollow fullerenes as drug delivery devices. Some researchers believe they can be used to help deliver medications such as antibiotics and AIDS medications in ways that could improve treatment outcomes. They may also provide a way to coat contrast agents used in hi-tech scans, such as magnetic resonance imagery (MRI), to help them remain in the body longer and provide better images. Other researchers are exploring fullerenes in creating antimicrobial surfaces.
Continued research into fullerenes has led scientists to uncover more than one thousand other new compounds. These include nanotubes, another form of carbon similar to fullerenes that resembles a tube made of rolled-up wire. The applications for fullerenes and the impact of their discovery extend to the fields of physics, chemistry, and geology.
Bibliography
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