Bulk and surface properties of matter

• What is the size range of nanoparticles?

  1. 100 nanometers
• How many atoms do nanoparticles typically contain?

  A few hundred atoms
• How do nanoparticles compare in size to fine particles (PM2.5)?

  Nanoparticles are smaller than fine particles
• What is the diameter range of fine particles (PM2.5)?

  100 to 2500 nanometers
• What is the diameter range of coarse particles (PM10)?

  1 x 10^-5 m to 2.5 x 10^-6 m
• What are coarse particles often referred to as?

  Dust
• What happens to the surface area to volume ratio as the side of a cube decreases by a factor of 10?

  The surface area to volume ratio increases by a factor of 10
• What are fullerenes in relation to nanoparticles?


  Fullerenes are a type of nanoparticle
• Why do nanoparticles have different properties compared to the bulk chemical they are made from?

  Due to their high surface area to volume ratio
• How does the high surface area to volume ratio of nanoparticles affect their effectiveness?

  Smaller quantities are needed to be effective
• What are the uses of nanoparticles?

  • Good catalysts due to high surface area to volume ratio
  • Highly selective sensors
  • Stronger, lighter building materials (nanotubes)
  • New cosmetics (e.g., sun tan cream, deodorant)
  • Lubricant coatings for artificial joints and gears
  • Conduct electricity for small electrical circuits in computers
• What are some possible disadvantages of nanoparticles?

  They may be toxic and can enter the brain from the bloodstream
• What concerns exist regarding the toxicity of nanoparticles?

  They may cause harm if they enter the brain from the bloodstream