Paints And Pigments

Question 0

What does a colloid consist of?

Eg paint

Answer 0

Tiny particles (solid, liquid or gas) suspended in a liquid. 
Colloids don't separate because the droplets are too small.

Question 1

Describe the 3 bits that make up paint

Answer 1

Pigment - colour
Binding medium - liquid carrying pigment
Solvent - thins paint so it will spread

Question 2

Describe what happens as emulsion paint dries on walls.

Answer 2

The solvent (water) evaporates leaving behind a thin layer of binding medium (a polymer) and pigment.

Question 3

Why are emulsion paints good for walls?

Answer 3

Fast drying, no harmful fumes.

Question 4

What are traditional oil paints made up of?

Answer 4

Pigment
Binding material - oil
Solvent - organic compound that will dissolve oil

Question 5

What are the properties of oil paints and what are they used for?

Answer 5

They are glossy, waterproof, hard wearing but have toxic fumes
Used for outside doors + metalwork.

Question 6

How do oil paints dry?

Answer 6

Solvent evaporates
Then oil oxidised by oxygen in air.
Takes longer