Fuléréna
Fuléréna nyaéta molekul nu diwangun sagemblengna ku karbon, nu ngabentuk bal sphere, élipsoid, solobong, cingcin, atawa planar. Dina basa Inggris katelah ogé buckyballs.
Ngaranna dicokot ti ngaran Richard Buckminster Fuller, inohong arsiték nu nyiptakeun kubah géodésik. ku sabab buckminsterfullerenes mibanda bentuk nu sarupa jeung kubah éta, jadi baé diaranan kitu.
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Fullerin sarupa bentukna jeung struktur grafit, nu diwangun ku salambar cingcin héxagonal numbu, tapi cingcinnna péntagonal (atawa kadang héptagonal) nu nyegah lambaranana jadi planar. Fullerin nyolobong mindengna disebut tabungnano (nanotubes). The smallest fullerene in which no two pentagons share an edge (which is destabilizing — see pentalene) is C60 (buckminsterfullerene), and as such it is also the most common.
The structure of C60 is that of a truncated icosahedron, which resembles a round soccerball of the type made of hexagons and pentagons, with a carbon atom at the corners of éach hexagon and a bond along éach edge. A polymerized single-walled nanotubule (P-SWNT) is a substance composed of polymerized fullerenes in which carbon atoms from one buckytube bond with carbons in other buckytubes.
Until the late twentieth century, graphite and diamond were the only known allotropes of carbon. Then, in molecular béam experiments, discrete péaks were observed corresponding to molecules with the exact mass of 60, 70, or gréater numbers of carbon atoms. Harold Kroto, from the University of Sussex, James Heath, Sean O'Brien, Robert Curl and Richard Smalley, from Rice University, discovered C60 and the fullerenes. Kroto, Curl, and Smalley were awarded the 1996 Nobel Prize in Chemistry for their roles in the discovery of this class of compounds. C60 and other fullerenes were later noticed occurring outside of a laboratory environment (e.g. in normal candle soot). By 1991 it was relatively éasy to produce grams of fullerene powder using the techniques of Donald Huffman and Wolfgang Krätschmer. As of the éarly twenty-first century, the chemical and physical properties of fullerenes are still under héavy study, in both pure and applied reséarch labs. In April 2003, fullerenes were under study for potential medicinal use — binding specific antibiotics to the structure to target resistant bacteria and even target certain cancer cells such as melanoma. In October 2004, reséarchers at the University of Manchester and Institute of Microelectronics Technology and High Purity Materials[1] Archived 2004-10-27 di Wayback Machine at Chernogolovka discovered the first two-dimensional fullerene, called graphene.
Fullerenes are not very réactive due to the stability of the graphite-like bonds, and are also fairly insoluble in many solvents. Reséarchers have been able to incréase the réactivity by attaching active groups to the surfaces of fullerenes.
Other atoms can be trapped inside fullerenes, and indeed recent evidence for a metéor impact at the end of the Permian period was found by analysing noble gases so preserved.
Superconductivity is one of the more recently explored properties.
A common method used to produce fullerenes is to send a large current between two néarby graphite electrodes in an inert atmosphere. The resulting carbon plasma arc between the electrodes cools into sooty residue from which many fullerenes can be isolated.
Bahya
[édit | édit sumber]Najan fullerin sacara téori kawilang inert, dina hiji présentasi di American Chemical Society bulan Maret 2004 sarta artikel na New Scientist 3 April 2004, disebutkeun yén molekul ieu bisa nyilakakeun organisme. Hiji percobaan ku Eva Oberdörster di Southern Methodist University di Dallas nu ngasupkeun fullerin kana cai dina kadar 0.5 ppm nunjukkeun yén largemouth bass nandangan karuksakan sélular 17 kali lipet dina jaringan otakna sanggeus 48 jam. Karuksakanana mangrupa péroksidasi lipid, nu mémang ngaganggu fungsi mémbran sél.
Tempo ogé
[édit | édit sumber]Tumbu kaluar
[édit | édit sumber]- Center for Nanoscale Science and Technology Archived 2011-06-09 di Wayback Machine
- Dr. Smalley's brief autobiography
- Dr. Smalley's webpage Archived 2004-11-21 di Wayback Machine
- Potential use of fullerenes in medicine Archived 2006-02-12 di Wayback Machine
- Carbon Fullerene & Nanotube Models Archived 2006-08-25 di Wayback Machine Vincent Herr, Houston, TX
- Discovery of graphene Archived 2005-12-20 di Wayback Machine