Glow sticks contain chemical substances, which emit light when they are mixed together. This phenomenon is called chemiluminescence. Glow sticks are known under the product names such as Cyalume and Lumica Light, which are used for recreational purposes during concerts and festivals. This article will focus on the chemistry behind glow sticks and highlight how they are made.
Youtube’s NurdRage channel, which contains many demonstrations of chemical experiments, illustrates the chemical reactions that occur inside glow sticks.
The movie shows the following chemical reaction, which proceeds simply by mixing the reagents.
When the activated oxalate (TCPO) reacts with hydrogen peroxide, 1,2-dioxetanedione is generated. Upon decomposition of this highly unstable 1,2-dioxetanedione species to two molecules of carbon dioxide, this releases energy, which excites a nearby dye molecule. The excited dye then relaxes by releasing a photon and emitting light. Using different types of dyes, it is possible to observe different colors of light. The structures of the dyes that were used in the video are shown below.
Glow sticks are sold with a solution of oxalate and dye being in one vessel and a solution of hydrogen peroxide contained in another vessel. By bending the sticks, the inner vessel breaks. This allows the two solutions to mix and react with each other, leading to chemiluminescence. Since the reaction is not reversible, the glow sticks can only be used once.
This reaction can be easily done in a chemistry lab if you have the reagents. However, obtaining these reagents in a household can be a bit problematic. Moreover, it is actually cheaper and easier to buy the glow sticks themselves. Nonetheless, for chemists, it may be interesting to try this out for yourself in the lab.