Glow sticks are light emitting tubes which does not produce any heat. They does not require any electricity or any other sources like batteries to light. So, what makes them glow? The answer is just a chemical reaction. Long back in 1970s our scientists became successful in inventing two chemical components which emit light when combined together. Even though they emit light they don’t produce any kind of electricity.
If we observe the construction of a glow stick it contains a plastic, transparent tube, which contains a glass vial filled with some chemical. The tube also holds some chemical substance along with the glass vial. The glass vial holds hydrogen peroxide and the plastic tube holds dye and diphenyl oxalate chemicals. These are the two substances which glow when combined together.
When the outer plastic container is bent, the glass vial inside it breaks releasing the chemical solution in to the other solution. When the tube is shaken the two substances mix with each other creating a chemical reaction that generates light. The chemical reaction is know as chemiluminescence. This reaction emits only light but not heat.
We can also increase the brightness of the light in glow sticks by placing them in hot climatic conditions. But exposing to higher temperatures decrease the life period of the glow stick. Conversely, exposing it to cool environments increases their life time but makes the light dull.
Glow sticks are non flammable, water resistant, and are apt for some situations like gas leakage. They are less expensive, easy to handle and can be carried away to any place easily. They are more useful for emergency situations. Especially when there are natural calamities they are highly helpful for rescue operations.
