John Congleton, Chemistry Home Page

Reaction Rates How Light Sticks Work
Light sticks operate throught the process of chemiluminescence. Chemiluminescence is the process whereby light is generated from a chemical reaction without the addition or generation of heat. In addition, during chemiluminescence electrons become excited and slowly relax to the ground state (on the order of seconds).
Inside the sealed glass ampule of a standard light stick is either dye or hydrogen peroxide. The hydrogen peroxide acts as the oxidant for the reaction that drives the light stick to create light. In the picture below, I have a test tube filled with dye and another test tube filled with hydrogen peroxide.

The emission of light is produced through four distinct processes: 1. The oxidation of oxalic phthalate by hydrogen peroxide, 2. Decomposition of 1,2-dioxetane-3,4-dione, 3. Transfer of energy from the 1,2-dioxetane-3,4-dione to the dye, 4. Relaxation of the dye to the ground state, and the release of energy as light.
The oxalic phthalate ester is oxidized by hydrogen peroxide to form phenol and the high-energy intermediate 1,2-dioxetane-3,4-dione.
The high-energy intermediate 1,2-dioxetane-3,4-dione then decomposes into two molecules of carbon dioxide. During this process, energy is transferred from the high-energy intermediate 1,2-dioxetane-3,4-dione to the dye, and the dye becomes excited.

The excited dye* then relaxes and releases energy in the form of light (hv).
The reaction can be sped up by adding heat and slowed down by removing heat.
Cooling the solution slows down the reaction rate. This can been seen by the reaction releasing less light.	This is the reaction at room temperature (it is our control).	Heating the solution causes the reaction to speed up and really get bright!