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Nanoworld and Nanomaterials

Nanoworld and Nanomaterials. Brandon Ng. Nanoworld. In measurements, we take nano as ^-9 Definition : The world at a microscopic level, as dealt with by nanotechnology. Nanotechnology. Definition : The engineering of functional systems at the molecular scale.

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Nanoworld and Nanomaterials

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  1. Nanoworld and Nanomaterials Brandon Ng

  2. Nanoworld • In measurements, we take nano as ^-9 • Definition : The world at a microscopic level, as dealt with by nanotechnology

  3. Nanotechnology • Definition : The engineering of functional systems at the molecular scale With 15/342 atoms, this parallel-shaft speed reducer gear is one of the largest nanomechanical devices every modeled in atomic detail.

  4. Nanoparticles • Definition : A particle having one or more dimensions of the order of 100nm or less • A bulk material should have constant physical properties regardless of its size, but at the nano-scale size-dependent properties are observed (eg. yellow gold, gray silicon)

  5. Gold • Pure gold has a bright yellow colour • Maintains without oxidizing in air or water • Physical properties : • Dense • Soft • Shiny (Not for nanoparticles) • Most malleable and ductile pure metal known

  6. NanoGold • Measured in nanometers as the gold particles contains only tens, hundreds of atoms (Note:1nm = 1 billionth a metre!) • Gold itself does not always glitter • If gold was created in tiny chunks, it turns red, blue, yellow and other colours

  7. NanoGold • 10nm particles absorb green light, appearing red. • Properties change dramatically from its bulk form • Becomes a very good catalyst • No longer a metal, but a semiconductor • Melting temperature decreases dramatically • Ceases to be noble • Magnetic • Equilibrium structure changes to icosahedral symmetry, or they are even hollow or planar

  8. NanoGold (Explanation) • Properties of NanoGold might be reconciled by the recently developed bond-order-length-strength(BOLS) correlation mechanism which indicates that the broken bond induced local strain and quantum trapping and the associated densification of charge and energy in the surface skin are responsible for the size induced behaviour.

  9. NanoGold (Explanation) • The shorter and stronger bonds in the surface skin not only lower the energy levels of the electrons but also enhance the electronegativity and hence make the less-coordinated atoms to gain electrons from the specimens, demonstrating the catalytic effect as observed

  10. Nanomaterials • Definition : A field which takes a materials science-based approach to nanotechnology • Other kinds of nanomaterials include • Carbon Nanotubes • Fullerenes (Carbon-60)

  11. Carbon Nanotubes • First observed by Sumio Iijima in 1991 • Extended tubes of rolled graphene sheets • Few nanometers in diameter • Important role in the context of nanomaterials, due to its novel chemical and physical properties • Two Types : • Single-walled • Multi-walled

  12. Carbon Nanotubes • Remarkable Properties : • Mechanically very strong (as stiff as diamond) • Flexible • Conduct electricity extremely well • Applications : • Reinforced composites • Sensors • Display devices

  13. Fullerenes • Discovered in the mid-1980s as a new class of carbon material • Spherical molecules about 1nm in diameter • Produced by resistively heating graphite rods in a helium atmosphere

  14. Fullerenes • Applications • Miniature “ball bearings” to lubricate surfaces • Drug delivery vehicles • Electronic circuits

  15. Other Uses of Nanoparticles • Fighting Cancer • Containers • Drugs

  16. Cancer Fighting Technology • Scientists are using nanoparticles and lasers to kill cancer cells by blowing them up from the inside • So far, the treatment has been tested in a lab setting on leukemia cells and cells from head and neck cancers

  17. Cancer Fighting Technology • Gold nanoparticles are placed inside the diseased cells and zapped with laser • The laser causes the particles to swell into “nanobubbles” that will burst the cells • Nanobubbles are created when gold nanoparticles are pelted by short pulses of laser • The bubbles can differ in size depending on the power of the laser • The larger they are, the more they can burst the cell they are in

  18. Cancer Fighting Technology • Nanobubbles are also able to blast through plaque that builds up and blocks arteries, which causes atherosclerosis

  19. Containers • A plastic container that uses silver nanoparticles to keep food, allows it to be fresher longer • Nanomaterials are being developed with enhanced mechanical and thermal properties to ensure better protection of foods from exterior mechanical, thermal, chemical or microbiological effects

  20. Containers • Silver is naturally anti-germ, anti-mould and anti-fungus • This special containers decreased bacteria growth by 98 percent over a day due to the silver nanoparticles

  21. Drugs • “If the disease doesn’t kill, the cure will” • Many therapeutic drugs administered by pill, syringe cream can be a hit or miss delivery system • Only 1 out of 100,000 molecules of an intravenous drug make it to the intended spot in the body

  22. Drugs • Bioengineer Frank Alexis has suggested that a way to improve targetting a drug and preventing it from being passed out of the body is enveloping it, protecting it • Envelopes used are nanoparticles

  23. Drugs • Think of an M&M • Nanoparticle – Outer candy shell • Medicine – Chocolate • The goal of the drug would be the same as for an M&M : To melt in the right place

  24. Drugs • A handful of nanoparticle medicines have already been approved for use for treating diseases, particularly cancers

  25. Frank Alexis • “Nanoparticles can be modified many ways. They can be coated so that they can be durable and stable. They can be patterned so that they match up like a key and lock to connect to certains cells, tissues and organs. Some drugs are not taken up because of their physical and chemical properties”

  26. References • http://www.thefreedictionary.com/nanoworld • http://www.crnano.org/whatis.htm • http://www.sciencedaily.com/releases/2004/04/040428062059.htm • http://www.scitopics.com/Nanogold_chemistry.html • http://www.indianofficer.com/forums/science-technology/6592-properties-nanomaterials.html • http://news.techworld.com/green-it/3212389/cancer-fighting-technology-uses-nanoparticles/?olo=rss • http://www.foodproductiondaily.com/Packaging/Container-uses-nanoparticles-to-extend-shelf-life • http://www.physorg.com/news174219683.html

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