New materials Flashcards
What are the two groups of new materials?
- Smart materials.
- Nanoparticles.
How do smart materials behave?
Very differently depending on the conditions (e.g. temperature).
What is an example of a smart material?
Nitinol.
What nitinol’s nickname?
A shape memory alloy.
What is nitinol?
A metal alloy (about half nickel, half titanium).
What can you do to nitinol?
When it’s cool you can bend it and twist it like rubber.
What happens when nitinol is bent too far?
It stays bent.
What can you do after you’ve bent nitinol to far that it stays bent?
You can heat it above a certain temperature, and it goes back to a remembered shape.
What is nitinol used in?
- Glasses frames.
- Dental braces.
Why is nitinol used in glasses frames?
Because if you accidentally bend them, you can just heat them above a certain temperature (put them in a bowl of hot water) and they return to their shape.
Why is nitinol used in dental braces?
As in the mouth it warms and tries to return to a remembered shape, and so it gently pulls the teeth with it.
What are nanoparticles?
Really tiny particles, 1-100 manometres across.
What is one nanometre?
0.000000001 m.
What do nanoparticles contain?
A few hundred atoms.
What do nanoparticles include?
Fullerenes.
What are fullerenes?
Molecules of carbon.
What are fullerenes shaped like?
Hollow balls or closed tubes.
How are the carbon atoms in fullerenes arranged?
In hexagonal rings.
What do different fullerenes contain?
Different numbers of carbon atoms.
What does a nanoparticles have in comparison to the chemical it is made from?
Very different properties (e.g. fullerenes have different properties from the big lumps of carbon).
What can we do to fullerenes?
Join them together to form nanotubes.
What are fullerene nanotubes?
Tiny hollow carbon tubes, a few nanometres across.
What can fullerene nanotubes be used to do?
Reinforce graphite in tennis rackets.
Why are fullerene nanotubes used to reinforce graphite in tennis rackets?
As all the covalent bonds make carbon nanotubes very strong.
What is using nanoparticles known as?
Nanoscience.
What is happening in science regarding nanoparticles?
Many new uses of nanoparticles are being developed.
What new uses of nanoparticles are being developed in science?
- To make new industrial catalysts.
- To make sensors that detect one type of molecule only (highly specific sensors).
- To make stronger, lighter building materials.
- To make new cosmetics.
- In nanomedicine.
- To make new lubricant coatings.
- In tiny electric circuits for computer chips.
Why can nanoparticles be used to make new industrial catalysts?
As they have a huge surface area to volume ratio.
What are the highly specific sensors made by nanoparticles being used to test?
For water purity.
Why are nanoparticles used to make new cosmetics?
(E.g. sun tan cream and deodorant), because the small particles do their job but don’t leave white marks on the skin.
How can nanoparticles be used in medicine (nanomedicine)?
The idea is that tiny fullerenes are absorbed more easily by the body than most particles, so they could deliver drugs to the right cells where they are needed.
What are new lubricant coatings being developed for using nanoparticles?
They are being developed with fullerenes, to reduce friction (a bit like ball bearings) and could be used in places like artificial joints and gears.
Why are nanoparticles being used in tiny electric circuits?
As nanotubes conduct electricity.
