Fullerenes & Graphene (Edexcel GCSE Chemistry)

C₆₀ fullerene

• Fullerenes are a group of carbon allotropes which consist of molecules that form hollow tubes or spheres
• Fullerenes can be used to trap other molecules by forming around the target molecule and capturing it, making them useful for targeted drug delivery systems
• They also have a huge surface area and are useful for trapping catalyst molecules onto their surfaces making them easily accessible to reactants so catalysis can take place
• Some fullerenes are excellent lubricants and are starting to be used in many industrial processes
• The first fullerene to be discovered was buckminsterfullerene which is affectionately referred to as a “buckyball”
• In this fullerene, 60 carbon atoms are joined together forming 20 hexagons and 12 pentagons which produce a hollow sphere that is the exact shape of a soccer ball

The structure and bonding in C₆₀ fullerene - the football shaped molecule

Graphene

• Graphene consists of a single layer of graphite which is a sheet of carbon atoms covalently bonded forming a continuous hexagonal layer
• It is essentially a 2D molecule since it is only one atom thick
• It has very unusual properties make it useful in fabricating composite materials and in electronics

Graphene is a truly remarkable material that has some unexpected properties

• Graphene has the following properties:
  • It is extremely strong but also amazingly light
  • It conducts heat and electricity
  • It is transparent
  • It is flexible

• Strength: It would take an elephant with excellent balance to break through a sheet of graphene
  • It is very strong due to its unbroken pattern and the strong covalent bonds between the carbon atoms. Even when patches of graphene are stitched together, it remains the strongest material out there

• Conductivity: It has free electrons which can move along its surface allowing it to conduct electricity
  • It is known to move electrons 200 times faster than silicon
  • It is also an excellent conductor of heat

• Flexibility: Those strong bonds between graphene’s carbon atoms are also very flexible. They can be twisted, pulled and curved to a certain extent without breaking, which means graphene is bendable and stretchable

• Transparent: Graphene absorbs 2.3% of the visible light that hits it, which means you can see through it without having to deal with any glare
  • This gives it the potential to be used for making computer screens of the future