C2 - New Materials Flashcards
What is a nanometre in comparison to a metre?
A billionth of a metre
What is a nanoparticle?
A particle from 1 to 100 nanometres
What is the most common natural nanoparticle?
Pollutants from burning fossil fuels
Why do nanoparticles have different properties to larger versions of the same material
The much larger surface area to volume ratio
What are fullerenes?
Molecules of carbon shaped like hollow balls or closed tubes
They can be joined together to make nanotubes
What are the 7 uses of nanomaterials?
High surface area to volume ratio could help to make industrial catalysts
Can make sensors that detect only one type of molecule
Nanotubes can be used to make stronger and lighter building materials
Sun cream and deodorant made of nanoparticles don’t leave marks on the skin
Fullerenes are absorbed more easily by the body than other particles meaning that they could deliver drugs right into the cells they are needed
New lubricant coatings that massively reduce friction
Nanotubes conduct electricity so they could be used in tiny electric circuits
What is a smart material?
A material that changes one of its properties depending on its conditions
What is nitinol and what is it used for?
A shape memory alloy that returns to its original shape when heated
Used for braces because the heat of the mouth causes it to return to its original shape and gently pull the teeth in
Describe thermosoftening polymers
They don’t have cross-linking between chains so the chains are held together by weak intermolecular forces so they can slide over each other
Easy to melt
When it cools, the polymer hardens into a new shape
It can be melted and moulded again as many times as you like
Describe thermosetting polymers
They have stronger intermolecular forces called cross links that hold the chains firmly together
Doesn’t soften when heated
Strong, hard and rigid
How do you make polymers in a way that they will be more flexible?
High temperature and high pressure to make it more flexible
