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Nanoworld and Nanomaterials

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In measurements, we take nano as ^-9 Definition : The world at a microscopic level, as dealt with by nanotechnology Definition : The engineering of functional systems ... – PowerPoint PPT presentation

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Title: Nanoworld and Nanomaterials


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 (Note1nm
    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 doesnt 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 MM
  • Nanoparticle Outer candy shell
  • Medicine Chocolate
  • The goal of the drug would be the same as for an
    MM 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/2004/04/04042
    8062059.htm
  • http//www.scitopics.com/Nanogold_chemistry.html
  • http//www.indianofficer.com/forums/science-techno
    logy/6592-properties-nanomaterials.html
  • http//news.techworld.com/green-it/3212389/cancer-
    fighting-technology-uses-nanoparticles/?olorss
  • http//www.foodproductiondaily.com/Packaging/Conta
    iner-uses-nanoparticles-to-extend-shelf-life
  • http//www.physorg.com/news174219683.html
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