C1h Flashcards
what is a paint described as and what does this mean
a colloid: where the particles are mixed and dispersed within a liquid but are NOT dissolved
why don’t the components of a colloid seperate (form layers)
because the particles are small enough to not settle at the bottom
what are the three components of a paint and their purpose
binding medium - holds the paint together, sticks it to the wall
pigment - provides the colour of the paint
solvent - disperses the binding medium and pigment, making the paint more runny and “paintable”
what are emulsion paints and how do they dry
water based paints (water is the solvent) dry by being applied as a thin layer, then the solvent (often water) evaporates, taking heat from the surface
how do oil-based paints differ from emulsion paints
oil is the binding medium
they dry when the solvent evaporates and the oil is oxidised by oxygen in the atmosphere
how are thermochromic paints suited to specific uses
- they change colour at different temperatures e.g when heated
- used for baby bottles (changes colour when safe enough to drink) and kettles (changes colour when the water is near boiled)
why could we add acrylic paints to thermochromic paints
the acrylic paint is a set colour (e.g yellow) so when the thermochromic paint (e.g blue) is mixed with it, it appears green. when the temperature rises, the thermochromic paint goes colourless and the mixture just appears yellow
how do phosphorescent paints glow in the dark
- absorb and store energy during the day
- release it at night over a period time
