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Why are nanoparticles so useful? - OCR 21st CenturyGraphene and fullerenes

Nanoparticles are 1 nm to 100 nm in size. They have very large surface area to volume ratios. The properties of nanoparticulate substances are different from those of the same substance in bulk.

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Graphene and fullerenes

have very small sizes and large surface area to volume ratios. Their may also be arranged into tubes or rings.

Carbon can form nanoparticle structures with a variety of shapes. The form ball shapes and tubes. consists of a sheet of carbon atoms, one atom thick.

Graphene

Graphene is an of carbon. Its structure resembles a single layer of . Graphene has a very high . It is very strong because of its large regular arrangement of carbon atoms joined by . Like graphite, graphene electricity well because it has that are free to move across its surface.

Fullerenes

A fullerene is a allotrope of carbon. Two examples of fullerenes are and .

Nanotubes

A nanotube resembles a layer of graphene, rolled into a tube shape. Nanotubes have high , so they are strong in and resist being stretched. Like graphene, nanotubes are strong and conduct electricity because they have delocalised electrons.

Covalent structure of a nanotube
Figure caption,
Nanotubes can be several millimetres long but only a few nanometres wide

Nanotubes can be added to other materials, for example in sports equipment, to make them stronger.

Buckyballs

Buckyballs are spheres or squashed spheres of carbon atoms. They are made up of large molecules so are not classed as . Weak exist between buckyballs. These need little to overcome, so substances consisting of buckyballs are slippery and have lower than graphite or .

Covalent structure of buckminsterfullerene
Figure caption,
Buckyballs are nanoparticles that have 60 carbon atoms joined by covalent bonds

The ball structure means that this type of fullerene structure can be used to carry small molecules. This can be used to carry medical drugs into the body.