How Do Glow Sticks Work?

Glow sticks are chemical reactions waiting to happen! Most are made of an outer plastic casing with a small glass capsule inside. The outer tube is filled with dye, which determines the color of the glow stick, and a chemical called diphenyl oxalate. The glass within contains hydrogen peroxide, the same thing you might use to clean out a cut or scrape.

Glow Stick Science

When you crack the glowstick you break the glass, the hydrogen peroxide is released into the mixture. This causes a series of chemical reactions to take place. The main end products of this chemistry are carbon dioxide and energy, as well as another molecule we will talk about later. The energy that is released goes into the dye, which converts the chemical energy into light energy! The reaction happens slowly, so that the glow lasts for a long time. Companies can vary the amount of each chemical to have glow sticks that glow brightly for a short time or more dimly for a very long time! This reaction also forms something called phenol that is a somewhat toxic chemical. Repeated exposure to this chemical, and even its vapors can be dangerous. This is why breaking open a glow stick without proper protection is not advisable. There will be phenol and broken glass in the mixture, neither of which are good things to have around!

Glow Sticks and Temperature

Temperature is another great way to control chemical reaction speed. When we add energy by heating up the glow stick reactants, the molecules move faster and interact more often. Cooling the system takes energy away, literally slowing things down at a microscopic level. Clear containers of cold, warm, and boiling water give a great view of this chemical property!
In contrast, liquid nitrogen, at -321 degrees Fahrenheit, is so cold that it actually stops the luminescent reaction, making the glow sticks go dark. You can bring glow sticks back to life by allowing them to absorb energy in a warmer environment.

Glow sticks in water Gif

If you have any questions about activities at AstroCamp, please reach out! We’re so excited about this summer’s camp session and cannot wait to meet the children and see them thrive while expressing their creativity.