1. nano? What’s so big about Zoe Schnepp
Why nanotechnology is thought to be so important
How you go about making nano-materials
Quite a few examples of nanotech research
Applications and safety
Zoe
Schnepp

2. New materials
Know that a range of new materials are being developed that involve the use of nanoparticles.(D-C)
Know the size of nanoparticles and be able to find out about carbon nanoparticles (D-C)
Explain how nanoparticles are different from ordinary sized particles of the same material. (B-A*)

3. Nanoscience
Use the information supplied to make simple notes about the SIZE of nanoparticles, the properties of particular nanoparticles, how they are different from the properties of the ordinary bulk materials.
Describe and explain particular applications of nanomaterials.

4. Nanoscience
Nanoparticles vary between 10 and 1000 atoms in size.
In this size range properties of materials change. e.g. Nanosilver becomes antiviral, antifungal and antibacterial so sprays can be used to clean operating theatres in hospitals and coat the inner surfaces of fridges. Titanium dioxide can be used in sunscreens because it blocks uv light but is transparent so does not cause white smears on the skin.
Other opaque substances become transparent (copper), unreactive materials become catalysts (platinum and gold),insulators become conductors (silicon) and materials change colour (e.g. gold nanaparticles are deep red in solution.)
Health.
Early detection of cancer and targeted drug delivery improve survival rates.
Possible risks:
Easy absorption through skin may lead to long term, harmful effects.

5. NANOSCIENCE
Refers to the science of structures that are 1–100nm in size
Nanoparticles Show different properties to the same materials in bulk
and have a high surface area to volume ratio
This can lead to the development of…
new computers
new catalysts
highly selective sensors
new coatings
stronger and lighter construction materials
new cosmetics such as sun-tan creams and deodorants
Scientifically, NANO means one thousand millionth (10-9)

6. WHAT IS NANO? 10mm 1mm (1,000,000nm) 0.1mm 0.01mm
Ultraviolet
Infrared
Microwave
0.1nm
10-2m
10-3m
10-4m
10-5m
10-6m
10-7m
10-8m
10-9m
10-10m
X-ray
Red blood cells
(~2-5μm)
Virus
(10-300nm)
Hair (~60-120μm)
DNA
(~2nm diameter)
Buckyball
(~1nm)
Gold atom
(135pm)
highlights/ html

7. Gold nanoparticles 100nm Image courtesy of Martin Hollamby
Micelles aren’t fixed, the surfactant molecules are continuously detaching and reattaching
Image courtesy of Martin Hollamby

8. Gold nanoparticles 5nm Image courtesy of Dr Sean Davis
Micelles aren’t fixed, the surfactant molecules are continuously detaching and reattaching
5nm
Image courtesy of Dr Sean Davis

9. Grey goo? Lots of people suspicious of nanotechnology
Worries about nano-robots that could self-replicate
Not that realistic
Brownian motion
Surface forces
BUT… body cells are effectively machines, with working parts on the nano-scale so nature has done it

10. Should treat these new nano-materials with caution
The real safety issue
Nanoparticles can be much more reactive than bulk material
Physical shape of material can seriously affect its toxicity
e.g. Asbestos
Serpentine
– flat sheets of atoms, harmless
Chrysotile
– nano-scale tubes
- Cause lung cancer
Should treat these new nano-materials with caution

11. Properties of Nanoparticles
The properties of substances
change entirely when in nano-sized
form.
Silver (macro)
Silver is a ductile and malleable metal (slightly harder than gold). It’s white with a metallic sheen capable of high shine. It has the highest electrical conductivity of any metal, even copper, and so is used to coat high quality electrodes/ electronic connections.
Pure silver also has the highest heat conductivity of all metals (diamond is the only non-metal that’s higher).
Because it reflects well, it’s used as a background for mirrors. Silver salts react to light, and silver nitrate is used in photographic film.
silver
e.g.
GCSE Science
Chapter 6

12. Properties of Nanoparticles
The properties of substances
change entirely when in nano-sized
form.
Silver (nano)
Silver in this form shows different properties:
It’s antibacterial
It’s antiviral
It’s antifungal
In each of the above examples, the silver nanoparticles prevent the organism’s respiratory enzymes from working, and so kills them in minutes.
Special socks are now available that include silver nanoparticles in order to heal conditions such as athlete’s foot. Research has shown that silver can also be used to treat many diseases, from flu to HIV.
GCSE Science
Chapter 6

13. Using Silver Nanoparticles
The silver nanoparticles in this sock kills odour causing bacteria and keep the socks fresh!
Coating the inside of the fridge with silver nanoparticles ensures that any microbe is killed and keeps the fridge clean hygienic and safe.
GCSE Science
Chapter 6
Nanoparticles in the washing machine ensure that the clothes are cleaned and disinfected.

14. Advantages and disadvantages of using nanoparticles
Could penetrate skin
and cause undesired
side-effects
Some have
antibacterial,
antiviral
and antifungal properties
Easily released
into the
environment
Preparation of
certain catalysts
Nanoparticles
Unusual properties,
leading to new uses
There is a lot that we
don’t know about
nanoparticles at the
moment. Much more
research is needed
before their use becomes
widespread
GCSE Science
Chapter 6