the art of mixtures
DESCRIPTION
The Art of Mixtures. By: Jennings Bryson, Suzanne Hodges & Kyle Oldham. What Makes Paint a Mixture. Paints are a type of mixture called a colloid. Paint contains several components, including the pigment, a solvent, a binding medium, and additives. Paint Ingredients. - PowerPoint PPT PresentationTRANSCRIPT
The Art of Mixtures
By: Jennings Bryson, Suzanne Hodges & Kyle Oldham
What Makes Paint a Mixture
• Paints are a type of mixture called a colloid. • Paint contains several components, including
the pigment, a solvent, a binding medium, and additives.
Paint Ingredients
• Pigment - gives the paint its color• Binding medium - a liquid polymer that
hardens to form a continuous layer when the paint dries
• Solvent - dissolves the binding medium and makes the paint more fluid.– (polymer: a large molecule)
• Additives- small amounts of substances modifying the paint properties
Physical Change
• Emulsion paints are water-based. Their solvent is water, and it dries when the water evaporates.– Physical change
Chemical Change
• The pigments in oil paints are dispersed in oil, which may itself be dissolved in a solvent.
• The solvent evaporates away when the paint dries. This leaves the pigment and oil behind. The oil oxidises to form a hard film. – This happens because the oil reacts with oxygen in the air.– Chemical changehttps://www.youtube.com/watch?v=Qc5snqAR8cI
http://www.bbc.co.uk/schools/gcsebitesize/science/ocr_gateway/carbon_chemistry/paintsrev1.shtml
Chemical or Physical
• Is mixing two different colors of paint a chemical or physical change?– It is a physical change because mixing the two
paints does not make a different substance, it simply makes a different color.
http://www.substech.com/dokuwiki/doku.pjp?id=composition_of_paintshttp://www.bbc.co.uk/schools/gcsebitesize/ocr_gateway_pre_2011/rocks_metals/1_paints_pigments2.shtml
Oil Paint Facts
• Most oil paints are undercoats or primers that will always come in a metal can
• The paint itself is flammable because it contains petroleum distillates(paint thinner)
• The vapor it gives off, volatile organic compounds, VOCs, can be very dangerous.
Oil Paint facts cont.
• Extra fact: – Before 1978, many paints’ pigments contained so
much mercury, that the neurotoxins were harmful to developing children, the adult brain, nervous system, and virtually every organ.
• Now, the danger of the mercury or VOCs subside after the paint dries.
• www.dejeronimopainting.com