New materials

Question 1

Why do smart materials behave differently?

Answer 1

The change depending on the conditions

Question 2

What is nitinol?
What can you do with it when it is cool?
If you then reheat it above a certain temperature what happens?

Answer 2

A shape memory alloy
Bend it and twist it like rubber, but if too far it stays bent
It goes back to a remembered shape.

Question 3

Why are smart materials useful for glasses frames?

Answer 3

If you bend them you can put them in warm water and they’ll move back into shape

Question 4

What is nitinol used for?

Why?

Answer 4

Dental braces

In the mouth it warms up and tries to return to the remembered shape so it gently pulls the teeth with it

Question 5

How big are nanoparticles?

1nm = how many meters?

Answer 5

1 to 100 nanometers across

0.000,000,001 m (9 ‘0’s in total)

Question 6

How many atoms do nanoparticles contain?

Answer 6

A few hundred

Question 7

What is one example of a nanoparticle?
What are these and what are their shapes?
How are the atoms that make them arranged?

Answer 7

fullerenes
Molecules of carbon shaped like hollow balls or closed tubes
The carbon atoms are arranged in hexagonal rings

Question 8

Different fullerenes contain different ….

Answer 8

numbers of carbon atoms

Question 9

What is the difference between the nanoparticle and the bulk chemical of that substance?

Answer 9

they have very different properties

Question 10

What can fullerenes do that makes them so useful?
They can be….
…. makes them very … sot hey are good for …

Answer 10

They can be joined together to form nanotubes, tiny hollow carbon tubes a few nano meters across
All of the covalent bonds make the nanotubes very strong so they can be used to reinforce graphite in tennis rackets

Question 11

What is nanoscience?

Answer 11

The use and development on nanoparticles

Question 12

Why are nanoparticles useful in industry?

Answer 12

They have a huge surface area to volume ration so are good for making new industrial cataysts

Question 13

How are nanoparticles used in relation to water?

Answer 13

They can be used to make sensors to detect one type of molecule and nothing else. They make highly specific sensors that are now used to test water purity.

Question 14

How are nanoparticles used in relation to construction?

Answer 14

They are used to make stronger and lighter building materials

Question 15

How are nanoparticles used in relation to cosmetics?

Answer 15

Sun cream and deodorant have been made using these. The small particles do their job but don’t leave white marks on the skin

Question 16

How are nanoparticles used in relation to medicine?

Answer 16

Nanomedicine is based on the idea that tiny fullerenes are absorbed more easily into the body than most particles, this means they could deliver drugs right into the cells where they’re needed.

Question 17

How are nanoparticles used in relation to coatings?

Answer 17

New lubricant coatings are being developed using fullerenes as they reduce friction in places like artificial joints and gears

Question 18

How are nanoparticles used in relation to electricity?

Answer 18

Nanotubes conduct electricity so they can be used in tiny electric circuits for computer chips

Question 19

What are plastics made up of?

Answer 19

Lots of molecules joined together in long chains

Question 20

What determines the properties of plastics?

Answer 20

The forces between the molecule chains

Question 21

What hold the atoms together in long chains in plastics?

Answer 21

Strong covalent bonds

Question 22

How are individual tangled chains of polymers held together?
So…
Which polymers don’t have cross links between chains?
Why is it easy to melt this type of plastic?
What happens when the polymer cools?
So what is the main good use of this type of polymer?

Answer 22

By weak intermolecular forces
…are free to slide over each other.
Thermosoftening polymers
The forces between the chains are easy to overcome so it’s easy to break these and melt the substance
It hardens into a new shape
They can be melted and remoulded as many times as needed

Question 23

How are some chains of polymers held together?
What type of polymers have these…. ?
How is the structure held?
What happens when the polymer is heated?
So what are the properties of this type of polymer?

Answer 23

Some have stronger intermolecular forces between the chains called cross links, these hold the chains firmly together
Thermosetting polymers have cross links
In a solid structure
It doesn't soften
They are hard, strong and rigid

Question 24

What affects the properties of a polymer? (2)

Answer 24

The starting materials and the reaction conditions

Question 25

How is low density polythene made? (two conditions)

What can it now be used for due to what property?

Answer 25

Heat ethene to about 200 degrees, under high pressure

It’s flexible and so can be used for bags and bottles

Question 26

How is high density polythene made? (two conditions)

What can it now be used for due to what property?

Answer 26

Lower temperature and pressure with a catalyst

It’s rigid and so can be used for water tanks and drain pipes

Question 27

What plastic would you use for the following and why?: (softening or setting)

1. Clothes
2. Disposable cups
3. Measuring cylinder

Answer 27

1 thermosoftening because it must be flexible
2 thermosetting because the cup mustn’t melt
2 thermosetting because the tube must be rigid

Question 28

What are nanoparticles? (2 options, or list a property) Exam question, 1 mark

Answer 28

Particles 1-100nm in size

Particles with different properties to normal particles of the same substance