C2aL9 Nanoparticles

Key Words

Catalyst - material that helps a reaction to proceed, but is not used up in the reaction.

Constructive - to do with making things.

Nanometres - 1 thousand millionth of a metre (10-9 m).

Nanoparticles - little bits of material consisting several hundred atoms.

Nanoscience - the study of nanoparticles.

Surface area - how much area covers an object.

Volume - how much space is contained in an object.

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Grade E

Nanoscience is about the study of molecular sized objects.  The prefix nano- means tiny.  Nanoparticles are objects that consist of a few hundred atoms, and their sizes are measured in nanometres.

1 nanometre (nm) = 1 thousand millionth of a metre (1 × 10-9 m), or the width of 10 hydrogen atoms.  A human hair is 100 000 nm across.

Laguna Design/Science Photolibrary

The picture above shows a capped nanotube which is made of atoms that form a hexagonal structure.  It has a high surface area to volume ratio.

Strange things happen at this level:

  • Nanoparticles of gold appear red;

  • Nanotubes like the one above can contain materials; they don't escape.

Much research is going into nano-scale objects, which can be used as light structural materials, or even in computers.

Grade C

The uses if nanomaterials include:

  • Better construction materials.  Aeroplanes have benefitted from carbon fibres, which are immensely string, yet very light.
  • Biosensors.
  • Methods of delivering drugs to target cells.
  • Catalysts, as the surface area is very large compared to the size of the object;
  • Scratch resistant materials.
  • Nano-sized electronic components to go into the new generations of computers.

Grade A

The sensationalist gutter press have made scare stories about mad scientists making self-replicating nanomaterials that will take over the world.

This sells newspapers, but makes people frightened.  They are often written by journalists whose knowledge of science would ensure that they would fail a GCSE exam.  And some of them are not that good at English either.

A careful debate is needed.