Glow In The Dark Paint
Glow in the dark paint is the one thing that both adults and children will enjoy a lot. This type of paint is readily available in hobby and party supply stores. Most of them use zinc-sulphide based phosphorescent pigments in an acrylic medium. There are also potentially safer water-based glow in the dark paints. Glow in the dark powder is also available at such stores.
Fluorescent paints glow only when they are irradiated by an energy source. A good example of how this works is a fluorescent tube. The current passing through the mercury vapor that is formed in the tube leads to creation of ultraviolet rays that hit the lining of phosphor in the tube. These rays blow the electrons in the region of the phosphor atoms into higher orbits. The electrons immediately fall back releasing the energy they absorb from the ultraviolet rays to visible light.
The phosphorescent paints, that is, the glow-in-the-dark paints work in a similar way except that once the light knocks the electrons into the higher orbits they stay there. The random thermal fluctuations in the crystal structure of the pigment knock the electrons back to their original orbits. This way the energy obtained from the light falling on it transfers to visible light that makes the paints glow. This is why the paints glow is weak but it lasts longer when the weather is cold. However, it appears to be brighter for very short durations when the weather is hot.
The color of the light released from a glow in the dark paint depends on the difference between the energy levels of the trough in which the electron is trapped and the ground state to which it falls back. If the energy difference is high then the color will be bluish. Mid-range energy differences show up as green or yellow-green and low energy as orange or red. This is for the simple reason that a blue photon has more energy than a red one.
There are zinc sulfide-based glow in the dark paints and strontium-based glow in the dark paints. The strontium-based paints are much more expensive than the regular ones but are worth it all. They are definitely much brighter than the zinc sulfide ones. The time for which these two types of glow in the dark paints actually glowed was also different. The strontium paint is clearly visible until eight hours while the glow of paints that have zinc sulfide, disappears after a mere fifteen minutes.
If you want to opt for the glow in the dark paint for professional purposes like to make toys or illuminating surfaces for parties, then you can go for the strontium based glow in the dark paints. If you only want to use them for at home for some creative project and not spend too much money on it then you should go for the zinc sulfide based glow in the dark paints.
Glow in the dark paints are available in many types according to the purpose of their application. There are water based acrylic paint, acrylic road marking paint, metal paint, epoxy floor paint, ceramic glaze paint, luminous enamel glaze etc.