Presentation on theme: "What is Nanoscience? The study of materials at the nanoscale."— Presentation transcript:
What is Nanoscience? The study of materials at the nanoscale.
Nano means small... very small It is a million times smaller than the smallest measurement you can see on your ruler!
a nanometre is… 0.000000001 metres OR 1 nm It is the unit we use to measure the building blocks of everything.
A human fingernail grows 1 nanometre every second. A man’s beard grows 5 nanometres every second.
This is a silver nanowire resting on a human hair. Look at a strand of your own hair and imagine how small that is…
Which of these is Gold? They both are!
Different sizes of particles react to light differently. At the nanoscale, strange things happen to materials – their properties can change. The colour of gold can range from purple to red depending on the size of the atom clusters.
Hundreds of years ago it was known as art Now we call it nanotechnology Red stained glass gets its colour from nanoparticles of gold that are only 20 nanometres across. Orange glass gets its colour from gold nanoparticles that are 80 nanometres across.
Why is small good?
Faster Lighter Can get into small spaces Cheaper More energy efficient
for example zinc particles in sun cream Large Zinc Oxide particles appear white. Nano-scale ZnO particles appear clear. Both block harmful radiation
Nanotechnology The use of nano ideas to make things better and cheaper.
How do we build small things? “Top-down”– building something by starting with a larger part and carving away material (e.g. like a sculpture). In nanotechnology, chips for computers are made by using acid to dissolve away unwanted material to get the right piece.
“Bottom-up”– building something by assembling smaller parts (e.g. like building a car engine or Lego). In nanotechnology, atoms and molecules interact to make making nanowires from metals like silver, or carbon nanotubes.
Uses of nanotechnology Health: Diagnostics, Cancer treatment and targeted drug delivery.
Uses of nanotechnology Materials: Sports industry, cosmetics, clothing and space elevators.
Uses of nanotechnology Technology: Faster processing, computers and smaller, more powerful mobile devices.
Uses of nanotechnology Environment Cleaner energy, better energy storage (batteries) and treatment of water.
Summary Nanoscience is about understanding how materials behave at the nanoscale. Properties of materials are different at the nanoscale compared to bulk materials. Nanotechnology is about applying our understanding of materials to make new products and improve existing ones. Points to remember: How big a nanometre is. Our bodies can detect nanoparticles. Nanoparticles are not all man made.
Activity 1 You will need A height chart or two metre rules. Fix the height chart vertically on a wall, or the two rules together. Lean your back against the height chart and stand up straight, heels touching the wall. Get someone to measure your height on the chart. Use a book held flat on your head for an accurate measurement – why? Write your name on the chart. Write your height on the chart. How tall are you in nanometres? In metres?
Activity 2 Each group has nine test-tubes carefully filled with 9 ml of water and numbered 1 to 9 First person - with the Pasteur pipette, carefully measure 1 ml of food colouring and add it to tube number 1. Mix the tube thoroughly so that the colour is even throughout. Everybody smell the tube What does it smell of? Does it smell the same as the original food colouring? Put a stopper in the tube or tape over the top..
* The next person takes 1 ml of liquid from the tube just closed and adds it to the next tube of water. Reseal the previous tube. Mix the tube thoroughly so that the colour is even throughout. Everybody smell the tube? What does it smell of? Does it smell the same as the original food colouring? * Repeat the instructions in red from * to * for each tube, one at a time. You are diluting the contents of tube 1 into tube 2, tube 2 into tube 3, and so on, until you dilute the contents of tube 8 into tube 9, repeating the mixing and smelling before doing the next dilution. Activity 2 page 2
At what point can you no longer see any red in the tubes? At what point can you no longer smell anything in the tubes? Is there a difference? In each tube the food colouring is ten times more dilute than the previous tube. By the time you reach the ninth tube the original food colouring has been diluted by a billion times, so for every part of food colouring there are a billion parts of water. This experiment shows the sensitivity of our senses. Our sense of smell allows us to detect very dilute amounts of food colouring after we are no longer able to see any trace of it. We can only see relatively large objects, but our sense of taste and sense of smell can detect individual molecules which are just tens of nanometres in size. Activity 2 page 3