1. Nanoparticles Marcus Han 3O3 (10)

2. Definition A particle having one or more dimensions of the order of 100nm (10 -7 m) or less From http://www.malvern.com.cn/LabChi/industry/nanot echnology/nanoparticle_defiition.htm 96nm 154nm 101nm 116nm 101nm 201nm

3. Gold Nanoparticles Bulk material Yellow Melting point is 1064°C. Nanoparticles Red Melting point is about 300°C at 2.5nm. Picture of Gold Nanorods, obtained by Transmission Electron Microscopy (TEM)

4. Uses of Gold nanoparticles Gold and palladium nanoparticles can be used to break TCE, a water contaminant, into non- toxic constituents. Glass beads hold the nanoparticles in place and water is pumped through the nanoparticles from the bottom up. Gold nanoparticles direct heat from infrared lasers to target cancer tumors. They can also detect early stage Alzheimer’s

5. Silver nanoparticles Silver has antibacterial properties. However as nanoparticles the antibacterial properties are magnified, as the surface area to volume ratio is increased, allowing them to easily interact with and fight with bacteria more efficiently. Silver nanoparticles

6. Uses of silver nanoparticles In refrigerators, washing machines, air- conditioners, clothing, baby pacifiers, food containers, detergent, surgical instruments, etc.

7. Carbon nanoparticles Ferromagnetic (carbon micro-particles are non-magnetic) Carbon nanotubes are used to deliver chemotherapy drugs to people with brain tumors.

8. Dangers In a study conducted in 2006 by Torsten Hansen and his coworkers, they did in vivo tests for carcinogenicity in bulk materials and nanoparticles. They implanted nickel, cobalt, SiO 2, TiO 2 and PVC in rats. Ni Co SiO 2 TiO 2 PVC

9. Dangers Quoted from Hansen: “Our data show that nanoparticles show a broad variety of biological effects extending from inflammation to malignant tumours, depending on their different chemical properties.” The site with cobalt nanoparticles had cancer- related activity earlier than at the site with cobalt bulk material.

10. Dangers However these results cannot be used for deducing if the materials are toxic to humans. In a previous study they tested the toxicity of these nanoparticles in vitro and found toxic effects only in cobalt nanoparticles.

11. Other dangers The fibrous (nanoparticle) form of serpentine minerals, chrysotile asbestos, is very carcinogenic, while other forms of the same chemical composition are have no harmful effects. Zinc oxide nanoparticles are toxic to human lung cells Chrysotile asbestos

12. Acknowledgements Definition of nanoparticle: http://www.malvern.com.cn/LabChi/industry/nanotechnology/nanoparticle_defiition.htm http://upload.wikimedia.org/wikipedia/commons/5/57/Nickel_chunk.jpg http://upload.wikimedia.org/wikipedia/commons/c/cf/Cobalt-3.jpg http://upload.wikimedia.org/wikipedia/commons/c/c5/DuneBlanche.jpg http://upload.wikimedia.org/wikipedia/commons/a/a5/Titanium%28IV%29_oxide.jpg http://www.global-b2b-network.com/direct/dbimage/50131030/PVC_Sheets.jpg http://www.ivanhoe.com/science/story/2008/04/418a.html http://www.nano.gov/html/facts/nanoapplicationsandproducts.html http://www.scientificamerican.com/article.cfm?id=will-nano-particles-present-big-health-problems http://www.science24.com/paper/9872 http://www.flickr.com/photos/kqedquest/435479282/ http://www.eng.tau.ac.il/~neliaz/Papers_Files/B11_38.pdf http://upload.wikimedia.org/wikipedia/commons/b/b2/Chrysotile.jpg