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					Nanoparticles

Marcus Han 3O3 (10)
                 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


                     101nm                    101nm

                   96nm                      116nm
        154nm                     201nm
             Gold Nanoparticles
  Bulk material     Nanoparticles
  • Yellow          • Red
  • Melting point   • Melting point
    is 1064°C.        is about 300°C
                      at 2.5nm.




Picture of Gold Nanorods, obtained by Transmission
Electron Microscopy (TEM)
     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
          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 Silver nanoparticles
  bacteria more efficiently.
     Uses of silver nanoparticles
• In refrigerators, washing machines, air-
  conditioners, clothing, baby pacifiers, food
  containers, detergent, surgical instruments,
  etc.
         Carbon nanoparticles
• Ferromagnetic (carbon micro-particles are
  non-magnetic)
• Carbon nanotubes are used to deliver
  chemotherapy drugs to people with brain
  tumors.
                        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,
       SiO2, TiO2 and PVC in rats.




Ni          Co        SiO2         TiO2
                                              PVC
                  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.
                   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.
                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
                     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

				
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posted:8/21/2011
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