2.4.1 Sizes of particles and their properties
Nanoparticles
- 1-100nm in size, a few hundred atoms thick
- High SA:vol ratio
- Smaller than fine particles (PM5) – diameters between 100-2500nm (1×10-7-2.5×10-6m)
- Coarse particles (PM10) – diameters between 1×10-5-2.5×10-6m – often referred to as dust
- Why good?
Stronger, harder, high SA:V ratio, very small – fit in small gaps
- 2.4.2 Uses of nanoparticles
Uses
- Catalyst for fuel – large SA:V ratio
- Drug delivery – tiny, absorb easily by body
- Sun cream – better skin coverage, more effective protection from UV rays
Problems
- Potential cell damage in body
- Harmful effects on environment
- Suggest why using nanoparticles is good for environment? (2)
- Tennis ball last longer (coz keep it hard)
- Less tennis ball needed to make
- Less material/energy used, pollution caused, waste
Suggest and explain why use of nanosized catalyst particles reduce cost of catalytic converter. (3)
- 1-100nm in size
- Large SA
- Less catalyst needed