Discovery and applications of fullerenes

1. Discovery and applications of fullerenes Leung Wai Chun F.6B (18) Crystalline form of C60

2. 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 atomsbuckyballs, 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.

3. Discovery 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

4. Common types of fullerenes discovered 1. Buckminsterfullerene, C60 • The smallest fullerene with no two pentagons share an edge • Named after Richard Buckminster Fuller, a architect who popularized the geodesic dome. Structure of C60, similar to a football

5. Common types of fullerenes discovered 2. Nanotubes • Cylindrical fullerenes • Can range from less than a micrometre to several millimetres in length. • high tensile strength, electrical conductivity and resistance to heat,relative chemical inactivity Rotating animation of nanotube

6. Applications 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.

7. Applications of fullerenes 2. Antioxidants & Biopharmaceuticals • Fullerene can sponge-up and neutralize >20free 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

8. Other applications of fullerenes 1. Catalysts • Marked ability to accept and to transfer hydrogen atoms; hydrogenation and hydrodealkylations.  • Inhibits coking reactions. 2. Water purification & bio-hazard protection • Singlet oxygen catalysis of organics with fullerene C60 3. Portable power • Proton exchange membranes for fuel cells 4. Vehicles • Enhanced durability 5. Medical • MRI agents

9. Reference Websites • http://www.seed.slb.com/en/scictr/watch/fullerenes/smallest.htm • http://www.seed.slb.com/en/scictr/lab/buckyball/index.htm • http://www.nasaexplores.com/show_912_teacher_st.php?id=030107112716 • http://www.chem.wisc.edu.edu/chemweek/BUCKYBALL/buckyball.html • http://www.chem.wisc.edu/~newtrad/CurrRef/BDGTopic/BDGtext/BDGBucky.html • http://www.nano-c.com/ • http://www.chemistry.wustl.edu/%7Eedudev/Fullerene/fullerene.html • http://www.ch.ic.ac.uk/local/projects/unwin/Fullerenes.html • http://www.edinformatics.com/math_science/fullerene.htm