Nanomaterials

Definition

Materials with at least one dimension in the nanometre range (roughly 1 to 100 nanometres), at which scale they often show properties very different from the same substance in bulk.

Key points

• A nanometre is one billionth of a metre; at this scale the large surface-area-to-volume ratio and quantum effects change strength, conductivity, colour, and reactivity.
• Carbon nanomaterials include carbon nanotubes (extremely strong and conductive), graphene (a single sheet of carbon atoms, very strong and an excellent conductor), and fullerenes.
• Nanoparticles are used in sunscreens, cosmetics, stain-resistant fabrics, water purification, drug delivery, and stronger lightweight composites.
• Graphene was isolated in 2004 by Geim and Novoselov, who won the 2010 Nobel Prize in Physics; it is one of the thinnest and strongest known materials.
• Concerns include the unknown long-term health and environmental effects of free nanoparticles, so their use is increasingly regulated.

Why it matters for CAPF

The definition of the nanometre scale, the special properties at that scale, and carbon nanotubes and graphene as flagship nanomaterials are recurring emerging-technology facts, with applications in defence armour and sensors.

Common confusion

Nanomaterials differ from bulk materials chiefly because of huge surface area and quantum effects, not merely because they are small in amount. Graphene is a single layer of carbon (two dimensional), while a carbon nanotube is rolled into a cylinder; both are carbon but structurally distinct.

Related concepts

concept nanotechnology, concept superconductors, concept semiconductor devices

Parent note

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