Compound Interest: The Chemistry of Glow Sticks (2024)

FAQs

Compound Interest: The Chemistry of Glow Sticks? ›

The action of snapping the glow stick breaks the glass cylinder, allowing the two solutions to mix and kicking of the reaction leading to the glow. The reaction that takes place is between the hydrogen peroxide solution and the diphenyl oxalate

The thin glass ampule in the lightstick contains dilute hydrogen peroxide. The ampule is surrounded by a solution containing a phenyl oxalate ester and a fluorescent dye. When the ampule is broken, the hydrogen peroxide and the oxalate ester react. A chemiluminescent reaction (a reaction that produces light) occurs.

Hydrogen peroxide + phenyl oxalate ester + dye ------>>>> trichlorophenol + carbon dioxide + excited dye.

Glow sticks actually contain two separate (separate rooms, areas, sections, etc.), with two different chemical solutions. One solution, in the case of most glow sticks, contains a diphenyl oxalate compound, along with a dye whose identity differs/changes depending on the desired colour.

No light can be released until the chemicals are mixed together. When you mix the chemicals together by cracking the glow stick, they react to make new chemicals and release excess energy in the form of light, transforming chemical energy into light energy.

[continued on back] When a glow stick is bent or cracked, it will begin to glow. A chemical reaction occurs. During a chemical change, two chemicals react with each other to form a brand-new chemical. The glow stick has two substances— one inside the plastic case, the other inside a glass tube within the plastic case.

Contrary to what one might think, glow stick chemical reactions are endothermic. Yes, they are giving off visible light, but they are not giving off heat (light in the infrared region).

Chemiluminescence (also chemoluminescence) is the emission of light (luminescence) as the result of a chemical reaction, i.e. a chemical reaction results in a flash or glow of light. A standard example of chemiluminescence in the laboratory setting is the luminol test.

The Science Behind the Fun

Stored energy is called potential energy. Glow sticks contain potential energy in the form of chemicals: fluorescent dyes and a chemical called hydrogen peroxide. No light can be released until the chemicals are mixed together.

What chemical glows forever? ›

Back in the day, radium and zinc sulfide paint was used to paint the numbers on wristwatches and table clocks. The Radium emitted radiation which caused the zinc to glow green. This emission of radiation was constant, so the numbers glowed 24/7 on there own. The half life of radium is about 2600 years!

The substance inside these glowing items is usually dibutyl phthalate - a clear, oily, colorless liquid. It is low in toxicity but can cause irritation to any part of the body that it comes in contact with, including the eyes, skin, and mouth.

This increased motion causes the light to brighten and to last for a shorter amount of time. Slower moving molecules (cooler temps) make the chemical reaction in the glowstick slow down. This decreased motion causes the light to dim and to last for a longer amount of time.

The glow stick's outer plastic tube holds a solution of an oxalate ester and an electron-rich dye along with a glass vial filled with a hydrogen peroxide solution. The signature snap that starts the reaction signals that you've broken the glass tube, releasing the hydrogen peroxide.

American Cyanamid's Cyalume light sticks are based on the reaction of bis(2,4,5-trichlorophenyl-6-carbopentoxyphenyl)oxalate (CPPO) with hydrogen peroxide. A similar reaction occurs with bis(2,4,6-trichlorophenyl)oxlate (TCPO) with hydrogen peroxide. An endothermic chemical reaction occurs.

Demonstrating the glow stick reaction

The initial oxidation product is 1,2-dioxetanedione, which rapidly decomposes to electronically excited carbon dioxide. Alone this will not efficiently chemiluminesce but a fluorescent dye can capture energy from the CO₂ efficiently and release this in the form of visible light.

The outer plastic tube of the glow stick holds a solution of oxalate ester and an electron-rich dye. The inner chemical is a hydrogen peroxide solution encased in a glass tube. The cracking sound you hear when you snap a glow stick is the glass tube breaking.

Glow sticks do not have a recycle phase in their life cycle, as the chemicals inside of the plastic tube are toxic, so they are sent directly to landfills upon disposal. As these glow sticks contain high amounts of plastic and chemicals, disposing them requires a high amount of embodied energy.

Chemiluminescence is the emission of photons (electromagnetic radiation as light) when chemically excited molecules decay to ground state following a chemical reaction. In bioluminescence, light emission involves reactions in living organisms.

Once it's unleashed, H₂O₂ triggers a chemical chain reaction that puts the glow in the stick. The hydrogen peroxide reacts with these molecules in the outer tube to form a highly unstable compound that quickly breaks down into CO₂, releasing energy that excites the dyes and produces light.