Nanochemistry

1. nanochemistry

2. What is an allotrope? An allotrope is a different form of the same element. For example, Diamond and Graphite are both allotropes of Carbon.

3. Diamond: Properties Hard material Strong covalent bonds High melting point No free electrons Doesn’t conduct Insoluble in water Transparent and lustrous Carbon atoms Covalent bonds

4. Graphite: Properties Soft, slippery material Atoms arranged in layers Weak intermolecular forces Layers slide over each other Free moving electrons between layers Does conduct Used in pencils Black

5. Fullerenes They are spheres of only carbon atoms and are also allotropes of carbon One example is the Buckminsterfullerene (Buckyball) It has a formula C60 It is a black solid Dissolves in petrol to make a red solution Free moving electrons so conducts electricity

6. Fullerenes: Uses They can cage other molecules In the future this may be used to deliver drugs in small amounts for slow release. E.g. Cancer treatment

7. NANOTUBES Nanotubes are made by joining fullerenes together Properties Hexagons curled into a tube shape Very strong Conducts electricity Small with a large surface area Can be separated from liquid products for re-use Uses Reinforce Graphite in tennis racquets Semi conductors in electric circuits in modern computers and electric circuits Industrial catalysts

8. Semiconducting CdSe Quantum Dots 4 nm = 0.000004 mm Colour changes with Size!

10. Colloidal Au used in Ancient Roman times

12. Monodispersity can be improved by fractional precipitation3.9 ± 0.6 nm

14. Monodispersity can be improved by fractional precipitation3.9 ± 0.6 nm 6.2 ± 1.0 nm

15. Au Au X CO CO2 CO CO2 Metal Nanoparticles Chemistry changes with Size!