 Nanotechnology is the research of compounds in the range of 1 to 100 nanometers (1.0 x m to 1.0 x m).

Physical Techniques  Scanning probe microscopes can move individual atoms one at a time, or allow atoms to layer on top of each other.  Metals can be vaporized and when cooled, nanoparticles can be formed when atoms deposit in layers.

Chemical Techniques  Chemical reactions are used to position atoms in molecules.  For example, in DNA nanotechnology the specific base pairing that occurs can be utilized to build desired molecules.

 A carbon nanotube is a hollow cylinder made from carbon atoms arranged into hexagon rings.  The ends are a mix of hexagon and pentagon rings (think Buckminster fullerene)

 Carbon nanotubes are rigid and extremely strong—many times stronger than steel.  Steel from Damascus has been found to be the first evidence of nanotubes being used (although the metalsmiths would not have known they had created nanotubes). The swords and knives were known throughout the Arab world of being extremely strong, but the techniques have been lost in time and have not been replicated.

 Nanotubes can also act as electrical conductors or semiconductors depending on the length and number of walls (or layers) present. The smaller the diameter, the less it can conduct.  They can also be effective catalysts due to the tube having an increased ratio of surface area to volume. Elements, metal oxides and proteins can be inserted inside the tubes as well.

Applications  Used in invisible sunscreens with titanium or zinc oxides.  Bacteriocidal bandages with silver nanoparticles.  Heterogenous catalysts and microcircuits.  Potential uses are vaccines, electronics with higher storage capacities, and drugs targeted to cancer cells.

Health and Environmental Risks  The small size and distinctive properties could pose unknown health and environmental risks.  Small size means easy to inhale, and this could effect respiratory systems.  There are unknowns about how they could change the genetic makeup of cells or how they could affect the brain, how the immune system would respond, etc.  Nanotoxicology is concerned with the toxicity of nanoparticles. Some materials which are normally inert may become reactive at the nanoscale level.

ToK and Chemistry!!!!  Can industries be trusted to work at high social and ethical standards in nanotechnology?  What are the implications of using nanotechnology for the military and making cheaper, more powerful weapons?  Would nanotechnology widen the gap between the rich and the poor, or help bring it together?

 The last Chemistry Powerpoint you will see from Mr. Kostial!! Congratulations!!!