Presentation on theme: "Discovery and applications of fullerenes"— Presentation transcript:
1Discovery and applications of fullerenes Leung Wai Chun F.6B (18)Crystalline form of C60
2From left to right: Diamond, graphite, and fullerene. What is a Fullerene?The third allotropic form of carbon material (after graphite and diamond).A class of closed-cage carbon molecule, Cn, characteristically containing 12 pentagons and a variable number of hexagons.<300 carbon atomsbuckyballs, include the buckminsterfullerene, C60.Giant fullerenes include single-shelled or multi-shelled carbon structures, onions, and nanotubes.From left to right: Diamond, graphite, and fullerene.A geodesic dome shares the same geometric structure as a buckminsterfullerene.
3Discovery of fullerene In molecular beam experiments, discrete peaks were observed corresponding to molecules with the exact mass of sixty or seventy or more carbon atoms.In 1985, Harold Kroto, James R. Heath, Sean O'Brien, Robert Curl and Richard Smalley discovered C60, and then the other fullerenes.Kroto, Curl, and Smalley were awarded the 1996 Nobel Prize in Chemistry.Harold Kroto and Richard Smalley
4Common types of fullerenes discovered 1. Buckminsterfullerene, C60The smallest fullerene with no two pentagons share an edgeNamed after Richard Buckminster Fuller, a architect who popularized the geodesic dome.Structure of C60, similar to a football
5Common types of fullerenes discovered 2. NanotubesCylindrical fullerenesCan range from less than a micrometre to several millimetres in length.high tensile strength, electrical conductivity and resistance to heat, relative chemical inactivityRotating animation of nanotube
6Applications of fullerenes 1. Organic Photovoltaics (OPV)Fullerene acts as the n-type semiconductor (electron acceptor) as they are derivitized to increase their solubility.The most commonly used derivative in photovoltaics is C60, but C70 has been shown to have a 25% higher power conversion efficiency than C60.
7Applications of fullerenes 2. Antioxidants & BiopharmaceuticalsFullerene can sponge-up and neutralize >20 free radicals per fullerene molecule.hold great promise in health and personal care applications where prevention of oxidative cell damage or death is desirable.A skin care cream based on C60
8Other applications of fullerenes 1. CatalystsMarked ability to accept and to transfer hydrogen atoms; hydrogenation and hydrodealkylations. Inhibits coking reactions.2. Water purification & bio-hazard protectionSinglet oxygen catalysis of organics with fullerene C603. Portable powerProton exchange membranes for fuel cells4. VehiclesEnhanced durability5. MedicalMRI agents