This history of glow in the dark (GITD) materials goes back to the 16th century and is still very common today. These materials need energy to work, usually in the form of light. They are charged through that source of energy, after that they glow. You must have often seen people wearing bracelets and bands in different fluorescent colours like yellow, green, orange pink, etc that glow in the dark.
Glow in the dark bracelets can be created in different styles. Light colours can be used to create the ‘glow in the dark bracelets’. Usually ‘glow-in-the-dark’ bracelets are made with silicon. These bracelets glow in the dark and are usually worn by players, and even by celebrities and important people to promote their team, party, or business.
Sometimes they are just worn for fashion. When these bracelets are charged, they last from seconds to hours depending on the amount of light that the bracelet has to activate and the temperature present. Usually, the ‘glow in the dark’ bracelet glows for about 10 minutes, while some new ones now may last for hours. Usually it is not a very bright light and you need to be in complete darkness to see it.
These ‘glow in the dark’ products have phosphors. This material spreads out visible light after being energised. Usually phosphors are commonly used in TV screens and fluorescent lights. In a TV screen, an electronic beam hits the phosphors and energises it. These ‘glow in the dark’ products also contain phosphors, which charges and emit light in the dark. Phosphors have three features;
o Type of energy that are required to be energised
o The colour of the visible light that they create
o The amount of time they glow for after they are charged
To make a glow in the dark bracelet you need a phosphor that is charged with normal light and has a very long persistence. These phosphors are mixed into plastic, and are made into the shapes of a bracelet. Zinc Sulfide and Strontium Aluminates are the example of phosphors that helps these bracelets to glow in the dark.
Strontium Aluminates is rather new and when used in products they glow in the dark for a long time. You must be wondering now that you have a bracelet that does not need to be charged. They glow without charging. You are right. These products use phosphors mixed with a radioactive emission and charge the phosphor continuously, but this is quite an expensive method used in expensive watches only.
Sometimes these phosphors degrade with time and the bracelets that you have may stop to glow or glow less overtime. Most of the ‘glow in the dark’ items available today are not radioactive. The items produced since the 1970s that are radioactive, are aisle markers, compasses, exit signs, watches, and weapon sights, contain tritium, but bracelets do not include that. Still care should be taken that these bracelets should not be broken or eaten in the case of children, because it will be harmful to the body if eaten.