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NanoparticlesNanoparticles
Marcus Han 3O3 (10)
DefinitionDefinition
• 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/nanotechnology/nanoparticle_defiition.htm
96nm154nm
101nm
116nm
101nm
201nm
Gold NanoparticlesGold 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)
Uses of Gold nanoparticlesUses 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 nanoparticlesSilver 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
Uses of silver nanoparticlesUses of silver nanoparticles
• In refrigerators, washing machines, air-conditioners, clothing, baby pacifiers, food containers, detergent, surgical instruments, etc.
Carbon nanoparticlesCarbon nanoparticles
• Ferromagnetic (carbon micro-particles are non-magnetic)
• Carbon nanotubes are used to deliver chemotherapy drugs to people with brain tumors.
DangersDangers
• 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
DangersDangers
• 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.
DangersDangers
• 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 dangersOther 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
AcknowledgementsAcknowledgements• 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