The photoluminescent (glow-in-the-dark)materials introduced in this Blog are Strontium Aluminate based material. . Up to today, it is the best afterglow material in terms of the brightness and the glowing time and the economics. It is safe, nontoxic, free of radioactivity.
It has the ability to absorb light (sunlight, fluorescent, incandescent,etc) and then to emit light. When ambient darkness occurs, it
becomes highly visible, lasts at least 8 hours. Our best products can last more than 20 hours.When the ambient light is off, the stored light is gradually released. The strongest glow is released during the first 30 minutes in darkness, which is the most critical period after a power failure in an emergency. Normally, the brightness lasts over 10 hours and fades over a period. when the light is recovered, it stores light again. So the photoluminescence process is recyclable.
The bases of most photoluminescent products are photoluminescent pigments that can be dispensed into coat, paint, ink, fabric, ceramic glaze or porcelain enamel, glass, flexible and rigid molded plastics. Typical products include self adhesive flexible vinyl tapes, rigid PVC marker strips, and silk-screened signage.
What is traditional afterglow material?1. ZnS:Cu pigmentSome of the first phosphors to be developed were inorganic zinc sulphide compounds. These phosphors typically absorb energy from deep blue and ultraviolet light and emit it as yellow-green light.This is useful in that the peak spectral distribution of the emitted light roughly coincides with the peak spectral sensitivity of the human visual system under isotopic (low-level) lighting conditions (which is around 510 nanometers).Zinc sulphide occurs in crystalline form, but is not photoluminescent by itself. This requires the addition of activator ions to the crystals, such as copper atoms. These ions absorb the excitation energy of the ultraviolet or visible light and later release it as visible light.The copper-activated zinc sulphide crystals(identified with the chemical symbol ZnS:Cu) are typically ground into a fine powder with a grain size of 3 to 15 micrometers to avoid light trapping and light piping effects.
The application of ZnS:Cu pigment is limited because the short glowing time and unstable light properties.
2. Radium afterglow materialThe discovery of Radium created the history of long afterglow material,but its radioactivity kept itself away from the application.