Paints and Pigments Flashcards
What is a pigment?
The substance that adds colour to the paint
What is the binding medium?
The substance that sticks the pigment to the surface being painted
What is the role of the solvent?
To thin the paint so it spreads easier
What is a colloid?
A colloid is a mixture in which one substance is spread or dispersed evenly in another substance. None of the substances are dissolved.
How is paint a colloid?
Because the solid particles are dispersed evenly within the the liquid particles
What are thermochromatic paints?
Paints which are sensitive to temperature change
How do thermochromatic paints work?
They are made with liquid crystals which reflect BLUE-VIOLET light at high temperatures and RED-ORANGE light at low temperatures. This allows them to change their colour dependant on the temperature.
What are phosphorescent paints?
Paints that are able to glow in the dark?
How do phosphorescent paints work?
They absorb radiation when they are exposed to light, they store this energy and later release it at a low intensity over a period of time, creating the glow in the dark effect
What are emulsion paints?
Water based paints
How do emulsion paints dry?
1) Water evaporates
2) This leaves the other ingredients behind- including the pigments
3) Ingredients join together to form a tough, coloured layer
What is the solvent in oil paint?
The solvent is a hydrocarbon oil
How does oil paint dry?
1) The hydrocarbon oil evaporates
2) Oxygen in the air oxidises hydrocarbon molecules
3) They join together to form a very tough layer on the painted surface
