Glow in the dark powder, professionally called long afterglow luminescent material, is called luminous powder mainly because its luminous intensity is much weaker than that of sunlight and light, and it will be more “bright” in darker environments.
The luminous powder can be divided into two types. The first is called self-luminous luminous powder, also known as permanent luminous powder. It does not need to be excited by any external energy. Intermittent, uniform, and stable light, the luminous time is generally more than six months. The second type is called luminous powder, which refers to a material that can continue to emit light for a period of time after the light source is turned off after a short time exposure to light sources such as sunlight and ultraviolet light.
The zinc sulfide luminous powder and rare earth long afterglow luminous powder that we see in the market now belong to luminous powder, because it is non-toxic and harmless, cheap, and is used by more and more industries and fields. Due to the high manufacturing cost of self-luminous luminous powder, its radioactive elements are easy to cause harm to the human body, and it is difficult to find it on the market.
Early noctilucent materials added radioactive thorium and radium elements in the production process and used the energy provided by the radioactive source to excite light. This noctilucent powder did not need to “absorb light” to emit light. Noctilucent would not emit light until the radioactive source’s radioactive decay Disappeared, this material is a relatively backward product of technology decades ago. Because it is harmful to the human body, no one has produced it in the last 30 years and cannot find it. In the last ten years, rare earth long-acting noctilucent powders have been mass-produced and applied in various fields, and have the characteristics of high glow in the dark performance, non-toxicity, and non-radiation.