1.4 Nanoparticles 🧴

Nanoparticle

structure that is 1-100nm in size, only few hundred atoms

1nm =

10^-9 m

Properties of nanoparticles

different to bulk material as they have high surface area to volume ratios

Surface area to volume ratio

measurement of how surface area of a shape compares to its volume

If the side of a cube decreases by factor of 10

surface area to volume ratio increases by factor of 10

Smaller particles

have larger surface area to volume ratios

Uses of nanoparticles

Catalysts, in electronics, sunscreens

Advantages of nanoparticles in sunscreen

• provide better skin coverage

• give more effective protection from UV

• colourless once rubbed in to skin

• do not break down on exposure to sun

Disadvantages of nanoparticles in sunscreen

• breathing them in may cause lung inflammation and they could enter the bloodstream

• may enter body and cause cell damage

• could wash off skin and damage the environment

Risks are difficult to determine as

they have not been used for very long