properties of mater, nanoparticles

• Nanoparticles


  Particles 1-100 nanometers across, containing a few hundred atoms
• Particle sizes


  • Nanoparticles (1-100 nm)
  • Fine particles (PM2.5, 100-2500 nm)
  • Coarse particles (PM10, 1x10^-5 m - 2.5x10^-6 m)
• Coarse particles are often referred to as dust
• As the side of a cube decreases by a factor of 10

  The surface area to volume ratio increases by a factor of 10
• Nanoparticles


  Involve fullerenes
• Nanoparticles


  • They have different properties to the 'bulk' chemical they're made from, due to their high surface area to volume ratio
  • Smaller quantities may be needed to be effective than for materials with normal particle sizes
• Nanoparticles with different properties to bulk

  • Fullerenes have different properties to big lumps of carbon
• Uses of nanoparticles


  • Good catalysts due to high surface area to volume ratio
  • Produce highly selective sensors
  • Make stronger, lighter building materials (nanotubes)
  • New cosmetics (no white marks)
  • Lubricant coatings (reduce friction, used for artificial joints and gears)
  • Conduct electricity, used in small electrical circuits for computers
• There are some concerns that nanoparticles may be toxic to people, as they may be able to enter the brain from the bloodstream and cause harm