4c. From fullerenes (buckyballs) to carbon nanotube structures
Brown's Chemistry: Chemical Bonding and structure GCSE level, IGCSE, O, IB, AS, A
level US grade
9-12 level Revision Notes
should be able to explain the properties of graphene in terms of its
structure and bonding.
Know that fullerenes are molecules of carbon
atoms with hollow shapes.
The structure of fullerenes is often based on
hexagonal rings of carbon atoms but fullerenes may also contain rings
with five or seven carbon atoms.
The first fullerene to be discovered
was Buckminsterfullerene (a C60 molecule of hexagonal and
pentagonal rings) which has a spherical shape.
Carbon nanotubes are long
cylindrical fullerenes with very high length to diameter ratios.
their properties make them useful for nanotechnology, electronics and
You should be able to recognise graphene and fullerenes from
diagrams and descriptions of their bonding and structure and give
examples of the uses of fullerenes, including carbon nanotubes.
The first fullerene discovered was the C60
molecule, named buckminsterfullerene.
It is hollow and the
'surface' is made up of 20 hexagons and 12 pentagons.
The pentagons are necessary so the surface can
curve over to form a spherical molecule.
Other fullerenes are elongated to give the
shape of a rugby ball.
Ultimately they can be made so elongated they form
what are known as nanotubes - big molecules!
FULLERENES: A 4th form of carbon (another
allotrope of carbon) are
fullerenes or 'bucky balls'!
- They consists of a 3D connected arrangement of pentagonal, hexagonal or
heptagonal rings like
graphite. Alternating pentagonal rings of carbon atoms allow curvature of the
spherical surface, in fact curved sufficiently to form their
characteristic 'football' or 'rugby
ball' shapes and elongated closed tubes.
- Some fullerenes have rings of seven carbon
atoms, again to allow curvature of the surface of the hollow sphere
of the 'bucky ball'.
- This means fullerenes are 'hollow' molecules
in which other molecules can fit in.
Buckminster Fullerene C60
,the first to be discovered, is shown on the right and the bonds form a pattern like a soccer ball.
- Others are
oval shaped like a rugby ball. It is a black solid insoluble in
- All of the fullerenes are hollow with the
hexagonal and pentagonal rings of carbon atoms forming the surface.
- These 'molecular size'
fullerene particles behave quite differently to a bulk carbon materials like
graphite or diamond.
- Fullerenes are
considered giant covalent
structures - small ones, not tubular, are classed as simple
- Fullerenes do dissolve in
organic solvents giving coloured solutions (e.g. deep red in petrol
hydrocarbon solvents, and although solid, their melting points are not that
high because of weak intermolecular bonding attractive forces.
- Fullerene molecules have a large surface area
- potential for industrial catalytic functions e.g. attach catalyst
molecules to the surface of the fullerene molecule.
- Fullerene molecules may be used for drug
delivery into the body, they can enclose or 'cage' another molecule
e.g. of a medical formulation.
- Fullerenes are used as lubricants, the
molecules readily slide over each other.
- Fullerenes can be part of a catalyst
composite, catalysts can be attached to their large surface area.
- Fullerenes in the form
of carbon nanotubes can be used for reinforcing composite materials,
eg sports equipment like tennis rackets. More on nanotubes below.
A section of multi-layered graphite
One of the simplest 'buckyballs' C60
A longer buckminsterfullerene which
is 'rugby ball' or 'sausage' shaped, C72 etc.
A section of a
carbon nanotube e.g.
6 x 100 nm, the ends would
be like those of the 'sausage' above right.
All images © doc brown
NANOTUBES: Carbon based nanotubes are also fullerenes are
also mentioned here to
illustrate the different forms of carbon AND they can be
made into continuous tubes to form very strong fibres of 'pipe like'
molecules called 'nanotubes'.
- Carbon nanotubes are basically long
- Carbon nanotubes have a high length to
- Carbon nanotubes ...
- have a very high tensile
strength, strong when stretched,
- very good electrical conductivity and a relatively high
thermal conductivity i.e. good conductors of heat and electricity.
- Uses of carbon nanotubes – carbon
nanotechnology – examples of nanochemistry
- They can be used as
semiconductors in electrical circuits.
- They act as a component
of industrial catalysts for certain reactions whose economic
efficiency is of great importance (time = money in business!).
- The catalyst can be attached
to the nanotubes which have a huge surface are per mass of catalyst
- Their large surface area combined
with the catalyst ensure two rates of reaction factors work in
harmony to increase the speed of an industrial reaction so making
the process more efficient and more economic.
- Carbon nanotube fibres are very
strong and so they are used in 'composite materials' e.g.
reinforcing graphite in carbon fibre tennis rackets.
- This is partly due to carbon nanotubes have a
high length to diameter ratio.
- Carbon nanotubes or long fullerenes can 'cage'
other molecules and can be used as a means of delivering drugs
in controlled way to the body because the thin carbon nanotubes can
penetrate cell walls.
- Carbon nanotubes or fullerenes are an
important additive in other oil based lubricants to enhance their
- Additives are added to lubricating oils to
improve their effectiveness in reducing friction and as a chemical
stabiliser eg to inhibit
thermal degradation of the oil in high temperature situation, but
I'm not sure what the function of carbon nanotubes is in this case?
I suspect the reasons involve some complex physics of viscosity well beyond the
scope of these notes!
- More on
nanotechnology including carbon
nanotubes, nanoparticles - properties and
I've written pages with more
examples and more details on
silicon and silicon dioxide ('silica')
Giant covalent structures and other big
bonding and structure notes
Perhaps of interest?
Nanoscience – Nanotechnology –
Nanochemistry (index of pages)
Smart Materials Science (alphabetical index at top of page)
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