Nanotechnology

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Nanotechnology

• SIZE Sunscreen

Wan Ng Faculty of Education (Bundoora) La Trobe
University email w.ng_at_latrobe.edu.au
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Visualisation with different instruments

• The animation shows the visual macroscopic level
  to the invisible nano-scopic levels of the
  structure of a butterfly
• http//www.cneu.psu.edu/edToolsActivities.html

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Carbon Structures in nature
Graphite Diamond
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Nanotechnology manipulation of carbon atoms at
nanoscale level
Bucky ball 60 atoms arranged in pentagons and
hexagons
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Bucky Ball

• spherical molecule that is geometrically shaped
  with 60 carbon atoms combined in interlocking
  hexagons and pentagons, like that of an unfilled
  soccer ball that is hollow and caged-like
• buckyballs are extremely stable molecules, are
  able to withstand very high temperatures and
  pressures and good conductors of electricity.
  Research into buckyballs include the creation of
  new molecules by adding other atoms or molecule
  to the outside of the buckyballs, or trapping
  smaller molecules inside the buckyballs

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Potential uses of bucky balls

• ability to behave like 'molecular ball
  bearings', allowing surfaces to glide over one
  another
• when metal atoms are attached to buckyballs,
  they can function as catalysts, increasing the
  speed of chemical reactions.
• they can also be modified to act as
  superconductors at low temperature.

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Construct a bucky ball

• Use template provided

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Nanotechnology Sunscreen
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Electromagnetic spectrum
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Low energy
High energy

• A continuum of all electromagnetic waves arranged
  according to frequency and wavelength. The sun,
  earth, and other bodies radiate electromagnetic
  energy of varying wavelengths
• Electromagnetic Waves have different wavelengths
• Visible light waves are the only electromagnetic
  waves we can see
• We see these waves as the colours of the rainbow.
  Each colour has a different wavelength
• Red has the longest wavelength and violet has the
  shortest wavelength. When all the waves are seen
  together, they make white light
• UV has shorter wavelength and higher energy

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Visible Invisible Sunscreen

• Most sunscreen lotions are oil-in-water emulsions
• Zinc oxide (ZnO) is the traditional chemical
  used in sunscreen and it is what gives the
  sunscreen its white appearance
• Zinc oxide absorbs UV radiation

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• Why do we need to protect ourselves from UV?
• Why does zinc oxide appear white?

• UV is the component in solar radiation that
  causes sunburn and long term damage to the
  epidermis of cells - the precursor to skin
  cancer.
• The sunscreen is white because zinc oxide
  reflects visible light.
• The particles of zinc oxide in regular sunscreen
  are large compared to the wavelength of visible
  light

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• When the zinc oxide particles are made smaller
  than the wavelength of visible light they no
  longer reflect it as the visible light is able to
  pass between the particles.
• Lotions or creams containing nano-particles of
  zinc oxide is transparent, but are still absorbs
  UV rays
• The same explanation goes for titanium dioxide in
  sunscreen

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• View 2 min video at http//www.csiro.au/multimedia
  /ppf33.html
• Transcript CSIRO video transcript

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Sunscreen for bottles

• Visit CSIRO website to find out what this is
  about http//www.csiro.au/multimedia/pf5l.html

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Investigating effectivens of sunscreen as UV
blockers

• Use UV sensitive beads
• Refer to handout.