Paints and Pigments

1. Paint is a mixture called a colloid. A colloid is where the particles of pigment are mixed and dispersed with particles of a liquid but are not dissolved.2. Why do the components of a colloid not separate? -The particles are dispersed throughout the mixture and are small so they do not settle at the bottom. 3. Emulsion paints are water-based paints. 4. The difference between emulsion and oil-based paints drying: Most paints dry because paints are applied as a thin layer and the solvent evaporates. 6. Thermo chromatic pigments change colour when heated or cooled. Uses of thermo chromatic pigments are: warning of a hot cup and use in electric heaters. 7. There are only a few thermo chromatic pigments, the range of colours is increased by the mix of acrylic paints with the thermo chromatic pigments. 8. Phosphorescent pigments can glow in the dark because they absorb and store energy, then release it as light over a period of time. 9. The first "glow in the dark" paints were made using radioactive materials as pigments, phosphorescent pigments are much safer.