Did you know that glow sticks have chemical reactions?
This picture shows the chemical reactions that take place
When Glow Sticks are bent the inner glass tube is broken, releasing Hydrogen Peroxide Solution. Then it reacts with Diphenyl Oxalate which produces a 1-2 Dioxetandione, this product is unstable. Then it decomposes to Carbon Dioxide which releases energy. The energy gets absorbed by electrons in dye molecules. They subsequently fall back to their ground state and lose excess energy in the form of light.
The chemical reactions in glow sticks happen when you bend them to crack them. Before activation of the glow stick the light is mainly in the middle and then you bend it. While you bend the glow stick the glass vial inside breaks releasing the two chemicals that then go together and react to give off light.
Putting glow sticks in the freezer will help slow down the chemical reaction. This makes it so that the glow stick will have a dimmer glow for a longer period of time. If, you crack it all the way and don't put it in the freezer it will have a brighter glow but for a shorter period of time.