Glow sticks produce light through a chemical reaction between two isolated solutions contained within a plastic tube. When the inner glass vial is broken, the solutions mix and produce light through decomposition reactions involving dyes, diphenyl oxalate, and hydrogen peroxide. This light emission can last for a few hours. Glow sticks have various applications as inexpensive, disposable light sources that do not require batteries or generate heat, such as for entertainment, emergency lighting, and special effects. However, the chemical mixtures can cause skin irritation if spilled.

1. Glow Stick(Liquid Light)By: Cheng Wei Loon 2A1 04

2. IntroductionWhat is glow stick?A translucent plastic tube which emits lightContains isolated substancesWhen the glass capsule inside is broken by bending the stick, light is produced when the substances mixTherefore it can only be used once for a short period of time of about a few hours

3. Detailed explanationGlow sticks give off light when two solutions are allowed to mix. The sticks consist of a small fragile container within a flexible outer container. Each container holds one of the two solutions. When the outer container is bent, it breaks the inner container, releasing the first solution into the second solution. After breaking, the tube is shaken to mix the two components. Usually to activate this reaction, you simply bend the glow stick.

4. Internal Chemical ReactionThe glow stick contains two chemicals and a suitable fluorescent dye (sensitizer, or fluorophor). The chemicals in the glass vial are a mixture of the dye and diphenyl oxalate. The chemical inside the plastic tube is hydrogen peroxide. By mixing the peroxide with the phenyl oxalate ester, a chemical reaction takes place, yielding two molecules of phenol and one molecule of peroxyacid ester (1,2-dioxetanedione). The peroxyacid decomposes spontaneously to carbon dioxide, releasing energy that excites the dye, which then relaxes by releasing a photon.

5. Internal Chemical ReactionThe wavelength of the photon—the colour of the emitted light—depends on the structure of the dye. The decomposition is a reverse [2 + 2] cycloaddition, which is a forbidden transition; so the reaction cannot release its energy as heat, but only as a single photon with an exact energy quantum.

6. Advantages as a light source (1)WaterproofBatteries are not neededGenerate negligible heatInexpensiveReasonably disposableAble to tolerate high pressures, such as those found underwater.

7. Advantages as a light source (2)Only kind of light source that is ideal safe for use immediately following an earthquake, hurricane, tornado, or other catastrophic emergency situation due to the fact that they do not use any kind of electricity to work and do not create any danger of sparkingUsed in night-time fishing as a lure.

8. Uses (1)Entertainment (1)Glowsticking– The use of glow sticks in dancingFrequently used for entertainment at parties (particularly raves), concerts and dance clubsCarried by marching band conductors for night-time performancesUsed in Hong Kong during Mid-Autumn FestivalUsed in Iceland during New Year’s Eve

9. Uses (2)Entertainment (2)Glow sticks carried by Trick-or-Treaters on Halloween neatly serve multiple functions as toys, readily visible and unusual night-time warnings to motorists, and luminous markings which enable parents to keep their brightly colour-coded children in sightUsed in balloon-carried light effectsUsed to create special effects in low light photography and film.

10. Uses (3)MoviesIn the Star Wars Trilogy, light sabers were made out of giant glow sticks attached to handlesThey would run out of light in a few hours and it was very costly to keep buying new ones

11. Ways to change life span of glow stickFreezingWhen glow sticks are placed in the freezer, the cold induces a solid-state to the mixture and slows down the photon releaseThis enables the glow stick to be kept for a few daysHeatingIn reverse, microwaving or running hot water over them speeds up the photon release and makes them brighter, but also diminishes the life of the glow stick

12. DangersGlow sticks contain hydrogen peroxide, and phenol is produced as a by-productIf the chemicals are spilled on the skin, they could cause slight skin irritation, swelling, or, in extreme circumstances, vomiting and nauseaIt is advisable to keep the mixture away from skin and to prevent accidental ingestion if the glow stick case splits or breaks

13. Pictures

14. How to make a glow stickhttp://www.youtube.com/watch?v=tItOOpyJP5k

15. THANK YOU