Nanotechnology SIZE & Sunscreen

Visualisation with different instruments  The animation shows the visual macroscopic level to the invisible nano-scopic levels of the structure of a butterfly ities.html ities.html

Carbon & Structures in nature Graphite Diamond

Nanotechnology & manipulation of carbon atoms at nanoscale level Bucky ball: 60 atoms arranged in pentagons and hexagons

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

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.

Construct a bucky ball  Use template provided

Nanotechnology & Sunscreen

Electromagnetic spectrum

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 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 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 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 UV has shorter wavelength and higher energy

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

 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

 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

  View 2 min video at 3.html 3.html   Transcript: CSIRO video transcript

Sunscreen for bottles  Visit CSIRO website to find out what this is about /pf5l.html /pf5l.html /pf5l.html

Investigating effectivens of sunscreen as UV blockers  Use UV sensitive beads  Refer to handout.