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How Do Glow Sticks Work?

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K S Lane is a student of science and is deeply passionate about educating others on her favourite topics.

Glow sticks are a nifty little invention, and one that most people take for granted. You snap them and then they light up- what’s the big deal? But, in fact, the chemistry behind how glow sticks work is fascinating. They contain a few key ingredients that, when mixed, undergo a chemical reaction that results in the characteristic bright, cheery glow.

You've probably used plenty of them in your life, but you do you know how glow sticks work?

You've probably used plenty of them in your life, but you do you know how glow sticks work?

What's in Glow Sticks?

Glow sticks of all shapes, sizes and colours contain two key ingredients: hydrogen peroxide and a phenyl oxalate ester. The hydrogen peroxide (H2O2) is encased in a thin glass tube within the glow stick, and the phenyl oxalate ester sits around it. It’s these two compounds that cause the glow of traditional glow sticks. To get the wide range of colours that make glow sticks so distinctive several different types of fluorescent dyes are used. For red, rhodamine B. For yellow, rubrene. For blue, diphenylanthracene. For green, it’s 9,10-bis(phenylethynyl)anthracene. A bit of a mouthful, I know. The technical names of the dyes aren’t particularly important; it’s their effect that matters, and I go into detail about this in the next paragraph.

Name of CompoundLocation in Glow StickPurpose

Hydrogen Peroxide

Inner glass tube

Mixes with the other solutions to initiate the reaction

Phenyl oxalate ester

Around the glass tube

Releases energy during decompositon

Fluorescent dye

Around the glass tube

Provides electrons that move from higher to lower energy levels, giving off different coloured lights

How do Glow Sticks Work?

When you crack a glow stick and it makes that satisfying crunching noise what you’re really doing is breaking the thin glass tube inside and allowing the hydrogen peroxide solution to mix with the phenyl oxalate ester and the dye. As the three liquids mix together they undergo a chemical reaction. The hydrogen peroxide and the ester react first, producing a different compound called phenol and a peroxyacid ester. The peroxyacid ester is highly unstable and goes through several different stages of decomposition into other compounds. Each of these stages releases energy.

Phew. Still with me?

The energy created is funnelled into the dye compound. Electrons within the dye are excited by all of the extra energy flooding in, but eventually fall back down to their resting state. As they fall from an energetic state to a less energetic state they release coloured light. This overall reaction is called chemiluminescence, and it’s what makes glow sticks light up.

A chemiluminescence reaction like the one pictured here is what causes glow sticks to light up.

A chemiluminescence reaction like the one pictured here is what causes glow sticks to light up.

Are There Different Types of Glow Sticks?

Glow sticks come in all shapes and sizes. There’s your average 'party' glow sticks with their bright colours and short lived luminescence, there’s long lived, plainer glow sticks to provide light for camping and there’s even glow sticks designed to light up the depths of the ocean for deep sea divers. There are minor differences in the composition of these different types of glow sticks of course, but essentially they all work in the same basic way. Hydrogen peroxide and phenyl oxalate ester (in some cases tert-butyl alcohol can be used instead) combine and then you get glow.

Even the military has been known to use glow sticks

Even the military has been known to use glow sticks

Are Glow Sticks Dangerous?

Since glow sticks are completely sealed they normally don’t pose a very serious safety hazard. The concern over glow stick safety generally comes from parents who are worried about their children biting down on the smooth, chewy, inviting 'toys' and ingesting their contents. None of the chemicals in glow sticks are known for being particularly toxic. The general advice circulating on the internet is to flush out the mouth, eyes, or whatever body part makes contact with the chemicals thoroughly and then to call poison control. All in all glow sticks aren’t all that dangerous, although their contents still don’t taste very nice and chowing down on one isn’t recommended (I ate a glow stick once when I was six, so I’m actually an authority on this).

Who Invented Glow Sticks?

The title for the inventor of the glow stick is a highly contested one. Most glow-enthusiasts, however, credit one Edwin A. Chandross, a chemist from Brooklyn, with the invention. Chandross discovered that a combination of hydrogen peroxide, oxalyl chloride and dye produced an interesting reaction that gave off light. His interest was more academic than commercial so he never filed a patent on the discovery (his loss, I guess). Instead, Michael Rauhut, a worker a chemical manufacturing company, jumped at the opportunity to carry Chandross’ work forward and found that using phenyl oxalate esters increased the glow-power of the reaction ten fold. The company he worked for eventually sold the rights to this discovery to another company, who sold it to another company, and as a result of this confusing mess there are more than five seperate patents for the technology.

Edwin Chandross probably would have made a fortune from inventing glow sticks if he'd only patented his creation!

Edwin Chandross probably would have made a fortune from inventing glow sticks if he'd only patented his creation!

Cool Glow Stick Hacks

  • To lengthen the time your glow stick works for make sure to keep it in a cooler environment like a fridge or freezer. The cooler temperature slows down the reaction, so the glow stick will dim a bit but will last for much longer.
  • To make your glow stick brighter try heating it up. The heat speeds up the reaction and increases the amount of light energy emitted, although this will shorten the duration of the glow considerably.
  • Try attaching glow sticks to your ceiling fan. The effect is pretty awesome.

In Summation

To recap, glow sticks contain a glass tube of hydrogen peroxide floating in a solution of a phenyl oxalate ester and a fluorescent dye. When you crack the glow stick the glass tube breaks and the chemicals mix together, undergoing a chemical reaction known as chemiluminescence. There are many types of glow sticks, but most of them work based on this same reaction. Glow sticks aren’t particularly dangerous, but you should avoid eating them, and the guy who discovered the original reaction and arguably invented the glow stick didn’t patent his invention and didn’t get any money from it. Idiot.

Test your knowledge here!

For each question, choose the best answer. The answer key is below.

  1. What part of the glow stick contains hydrogen peroxide?
    • The glass tube inside
    • Surrounding the glass tube
    • In the plastic coating
  2. Electrons release light energy when...?
    • They move from a lower energy state to a higher energy state
    • They react with H202
    • They move from a higher energy state to a lower energy state
  3. Who was the original inventor of the glow stick?
    • Edwin Chandross
    • Richard Kruskall-Wallace
    • Michael Rauhut
  4. The dye Rhodamine B is what colour?
    • Yellow
    • Red
    • Orange
  5. The dye diphenylanthracene is what colour?
    • Red
    • Green
    • Blue
  6. A phenyl ____ ester is a key component of glow sticks.
    • Oxalate
    • Oxalole
    • Amide
  7. If you come into contact with the chemicals in a glow stick you should?
    • Freak out
    • Flush the affected area with water and call poison control
    • You'll be dead before you have time to do anything
  8. If you put a glow stick in the freezer what happens?
    • It gets brighter and lasts for less time
    • It gets dimmer and lasts longer
    • It gets dimmer and lasts for less time
  9. Glow sticks can be used in which of the following situations?
    • To charge your mobile device
    • As weapons
    • Deep sea diving
  10. The chemical reaction that takes place in a glow stick is called?
    • Bioluminescence
    • Chemiluminescence
    • Chemosynthesis

Answer Key

  1. The glass tube inside
  2. They move from a higher energy state to a lower energy state
  3. Edwin Chandross
  4. Red
  5. Blue
  6. Oxalate
  7. Flush the affected area with water and call poison control
  8. It gets dimmer and lasts longer
  9. Deep sea diving
  10. Chemiluminescence

Sources and further reading:


Questions & Answers

Question: How long will a glow stick glow?

Answer: Honestly, how long a glow stick lasts depends entirely on the brand and the size. Most brands list how long their product lasts on the packaging, so my recommendation would be to check that. Standard glow sticks will usually last from between 6 to 10 hours, but again this can go up or down depending on the quality, size and also the temperature (glow sticks last longer in cooler temperatures).

© 2018 K S Lane

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