Nanoparticles

• What is the size range of nanoparticles?


  100 nanometers
• How many atoms do nanoparticles typically contain?


  A few hundred atoms
• How do nanoparticles compare in size to fine particles?


  Nanoparticles are smaller than fine particles
• What is the diameter range of fine particles?


  100 to 2500 nanometers
• 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 is one example of a nanoparticle that has different properties compared to larger forms of the same material?


  Fullerenes compared to big lumps of carbon
• 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) with no white marks
  • Lubricant coatings to reduce friction (for artificial joints and gears)
  • Conduct electricity (used in small electrical circuits for computers)
• What is a possible disadvantage of using nanoparticles?


  They may be toxic to people
• How might nanoparticles enter the brain?


  From the bloodstream
• What harm could nanoparticles potentially cause if they enter the brain?


  They may cause harm to brain function