A glow stick, also known as a light stick, chem light, light wand, light rod, and rave light, is a self-contained, short-term light-source. It consists of a translucent plastic tube containing isolated substances that, when combined, make light through chemiluminescence. The light cannot be turned off and can be used only once. The used tube is then thrown away. Glow sticks are often used for recreation, such as for events, camping, outdoor exploration, and concerts. Glow sticks are also used for light in military and emergency services applications. Industrial uses include marine, transportation, and mining.
Bis(2,4,5-trichloro-6-(pentyloxycarbonyl)phenyl)oxalate, trademarked "Cyalume", was invented in 1971 by Michael M. Rauhut, [1] of American Cyanamid, based on work by Edwin A. Chandross and David Iba Sr. of Bell Labs. [2] [3]
Other early work on chemiluminescence was carried out at the same time, by researchers under Herbert Richter at China Lake Naval Weapons Center. [4] [5]
Several US patents for glow stick-type devices were issued in 1973–74. [6] [7] [8] A later 1976 patent [9] recommended a single glass ampoule that is suspended in a second substance, that when broken and mixed together, provide the chemiluminescent light. The design also included a stand for the signal device so it could be thrown from a moving vehicle and remain standing in an upright position on the road. The idea was this would replace traditional emergency roadside flares and would be superior, since it was not a fire hazard, would be easier and safer to deploy, and would not be made ineffective if struck by passing vehicles. This design, with its single glass ampoule inside a plastic tube filled with a second substance that when bent breaks the glass and then is shaken to mix the substances, most closely resembles the typical glow stick sold today.[ citation needed ]
In the early 1980s the majority of glow sticks were produced in Novato, California by Omniglow Corp. Omniglow completed a leveraged buyout of American Cyanamid's chemical light division in 1994 and became the leading supplier of glow sticks worldwide until going out of business in 2014. Most glow sticks seen today are now made in China. [10]
Glow sticks are waterproof, do not use batteries, consume no oxygen, generate no or negligible heat, produce neither spark nor flame, can tolerate high pressures such as those found under water, are inexpensive, and are reasonably disposable. This makes them ideal as light sources and light markers by military forces, campers, spelunkers, and recreational divers. [11]
Glowsticking is the use of glow sticks in dancing [12] (such as in glow poi and wotagei). They are frequently used for entertainment at parties (in particular raves), concerts, and dance clubs. They are used by marching band conductors for evening performances; glow sticks are also used in festivals and celebrations around the world. Glow sticks also serve multiple functions as toys, readily visible night-time warnings to motorists, and luminous markings that enable parents to keep track of their children. Another use is for balloon-carried light effects. Glow sticks are also used to create special effects in low light photography and film. [13]
The Guinness Book of Records recorded the world's largest glow stick was cracked at 150 metres (492 ft 2 in) tall. It was created by the University of Wisconsin–Whitewater's Chemistry Department to celebrate the school's sesquicentennial, or 150th birthday in Whitewater, Wisconsin and cracked on 9 September 2018. [14]
Glow sticks are used for outdoor recreation, often used at night for marking. Scuba divers use diving-rated glow sticks to mark themselves during night dives, and then can turn off bright diving lights. This is done to enable visibility of bioluminescent marine organisms, which cannot be seen while a bright dive light is illuminated. Glow sticks are used on backpacks, tent pegs, and on jackets during overnight camping expeditions. Often, glow sticks are recommended as an addition to survival kits.
There are specific industrial uses of glow sticks, which are often used as a light source in circumstances where electric lighting and LEDs are not best suited. For example, in the mining industry, glow sticks are required for emergency evacuation in the case of a gas leak. Use of an electric light source in this case may cause an unintended explosion. Chemiluminescence, the type of light used in glow sticks, is a "cold-light" and does not use electricity, and will not cause a gas leak to ignite.
Glow sticks are also used worldwide in the marine industry, often used as fishing lures in long-line, recreational, and commercial fishing, as well as for personnel safety.
Glow sticks were originally invented by the US Military, [15] and are an essential part of military operations across land and sea, where they are more often referred to as chem lights. Glow sticks are also used within police tactical units, as light sources during night operations or close-quarters combat in dark areas. They are also used to mark secured areas or objects of note. When worn, they can be used to identify friendly soldiers during nighttime operations. [16] For search and rescue operations, glow sticks are often used during Man Overboard rescue scenarios to create a glowing trial back to the last known location of someone who is lost at sea.
Glow sticks are used by police, fire, and emergency medical services as light sources, similar to their military applications. Often, emergency rescue crews will hand out glow sticks in order to keep track of people at night, who may not have access to their own lighting. Glow sticks are sometimes attached to life vests and lifeboats on passenger and commercial vessels, to ensure night time visibility.
Glow sticks are often part of emergency kits to provide basic lighting and provide ease of identification in dark areas. They can be found in emergency lighting kits in buildings, public transportation vehicles, and subway stations.
Glow sticks emit light when two chemicals are mixed. The reaction between the two chemicals is catalyzed by a base, usually sodium salicylate. [17] The sticks consist of a tiny, brittle container within a flexible outer container. Each container holds a different solution. When the outer container is flexed, the inner container breaks, allowing the solutions to combine, causing the necessary chemical reaction. After breaking, the tube is shaken to thoroughly mix the components.
The glow stick contains two chemicals, a base catalyst, and a suitable dye (sensitizer, or fluorophor). This creates an exergonic reaction. The chemicals inside the plastic tube are a mixture of the dye, the base catalyst, and diphenyl oxalate. The chemical in the glass vial is hydrogen peroxide. By mixing the peroxide with the phenyl oxalate ester, a chemical reaction takes place, yielding two moles of phenol and one mole of peroxyacid ester (1,2-dioxetanedione). [18] The peroxyacid decomposes spontaneously to carbon dioxide, releasing energy that excites the dye, which then relaxes by releasing a photon. The wavelength of the photon—the color of the emitted light—depends on the structure of the dye. The reaction releases energy mostly as light, with very little heat. [17] The reason for this is that the reverse [2 + 2] photocycloadditions of 1,2-dioxetanedione is a forbidden transition (it violates Woodward–Hoffmann rules) and cannot proceed through a regular thermal mechanism.
By adjusting the concentrations of the two chemicals and the base, manufacturers can produce glow sticks that glow either brightly for a short amount of time or more dimly for an extended length of time. This also allows glow sticks to perform satisfactorily in hot or cold climates, by compensating for the temperature dependence of reaction. At maximum concentration (typically found only in laboratory settings), mixing the chemicals results in a furious reaction, producing large amounts of light for only a few seconds. The same effect can be achieved by adding copious amounts of sodium salicylate or other bases. Heating a glow stick also causes the reaction to proceed faster and the glow stick to glow more brightly for a brief period. Cooling a glow stick slows the reaction a small amount and causes it to last longer, but the light is dimmer. This can be demonstrated by refrigerating or freezing an active glow stick; when it warms up again, it will resume glowing. The dyes used in glow sticks usually exhibit fluorescence when exposed to ultraviolet radiation—even a spent glow stick may therefore shine under a black light.
The light intensity is high immediately after activation, then exponentially decays. Leveling of this initial high output is possible by refrigerating the glow stick before activation. [19]
A combination of two fluorophores can be used, with one in the solution and another incorporated to the walls of the container. This is advantageous when the second fluorophore would degrade in solution or be attacked by the chemicals. The emission spectrum of the first fluorophore and the absorption spectrum of the second one have to largely overlap, and the first one has to emit at shorter wavelength than the second one. A downconversion from ultraviolet to visible is possible, as is conversion between visible wavelengths (e.g., green to orange) or visible to near-infrared. The shift can be as much as 200 nm, but usually the range is about 20–100 nm longer than the absorption spectrum. [20] Glow sticks using this approach tend to have colored containers, due to the dye embedded in the plastic. Infrared glow sticks may appear dark-red to black, as the dyes absorb the visible light produced inside the container and reemit near-infrared.
On the other hand, various colors can also be achieved by simply mixing several fluorophores within the solution to achieve the desired effect. [17] [21] These various colors can be achieved due to the principles of additive color. For example, a combination of red, yellow, and green fluorophores is used in orange light sticks, [17] and a combination of several fluorescers is used in white light sticks. [21]
In glow sticks, phenol is produced as a byproduct. It is advisable to keep the mixture away from skin and to prevent accidental ingestion if the glow stick case splits or breaks. If spilled on skin, the chemicals could cause skin irritation, swelling, or, in extreme circumstances, vomiting and nausea. Some of the chemicals used in older glow sticks are carcinogens. [24] The sensitizers used are polynuclear aromatic hydrocarbons, a class of compounds known for their carcinogenic properties.
Dibutyl phthalate, a plasticizer sometimes used in glow sticks (and many plastics), has raised some health concerns. It was put on California's list of suspected teratogens in 2006. [25] Glow stick liquid contains ingredients that can act as a plasticizer, softening plastics onto which it leaks. [26] Diphenyl oxalate can sting and burn eyes, irritate and sting skin and can burn the mouth and throat if ingested.
Researchers in Brazil, concerned about waste from glowsticks used in fishing in their country, published a study in 2014 on this topic. [27] It measured the secondary reactions that continue within used glow sticks, toxicity to cells in culture, and chemical reactions with DNA in vitro. The authors found high toxicity of light stick solutions, and evidence of reactivity with DNA. They concluded that light stick solutions "are hazardous and that the health risks associated with exposure have not yet been properly evaluated."
Many glow sticks use the chemical TCPO, or trichlorophenol, which is highly toxic if inhaled or ingested and is toxic to organs if ingested or otherwise exposed [28]
A Danish Ministry of the Environment report investigated commercially available glow sticks and found evidence of glow sticks containing dibutyl pthalate, and concluded that this is in violation of the law. [29] From the report "that substance must not be used in toys or gimmick and gag articles as according to classification it may damage fertility or the unborn child. The risk arises after repeated or longer exposure." In this consumer investigation, it was also observed that certain glow stick packaging featured images of children on the front, while the back carried a warning label stating "not suitable for children." This inconsistency may lead to consumer confusion and raises questions regarding appropriate product marketing and safety communication. [29] Products on amazon can be marketed as child safe and non toxic, but these claims are unvalidated.
Glow sticks also contribute to the plastic waste problem, as glow sticks are single-use items and made from plastic. Additionally, since the inner vial is often made from glass and the chemicals inside are dangerous if improperly handled, the plastic used for glow sticks is non-recoverable by recycling services, so glow sticks are categorized as non-recyclable waste.
Safety data sheets for individual components of glow stick formulas recommend absorbing with sawdust or other absorbent material and in particular stress the importance of keeping waste away from water sources. One should not dump used glow stick fluid down the drain.
By the 2020s, work was being done to create safer glow sticks and alternatives. Canadian company Lux Bio developed glow stick alternatives such as the Light Wand which is biodegradable and powered with bioluminescence, rather than the chemiluminescence [30] [31] and LÜMI, which is a reusable and non-toxic alternative that glows with phosphorescence [32] and is chemically and biologically inert.
Fluorescence is one of two kinds of emission of light by a substance that has absorbed light or other electromagnetic radiation. When exposed to ultraviolet radiation, many substances will glow (fluoresce) with colored visible light. The color of the light emitted depends on the chemical composition of the substance. Fluorescent materials generally cease to glow nearly immediately when the radiation source stops. This distinguishes them from the other type of light emission, phosphorescence. Phosphorescent materials continue to emit light for some time after the radiation stops.
Luminescence is a spontaneous emission of radiation from an electronically or vibrationally excited species not in thermal equilibrium with its environment. A luminescent object emits cold light in contrast to incandescence, where an object only emits light after heating. Generally, the emission of light is due to the movement of electrons between different energy levels within an atom after excitation by external factors. However, the exact mechanism of light emission in vibrationally excited species is unknown.
Anthracene is a solid polycyclic aromatic hydrocarbon (PAH) of formula C14H10, consisting of three fused benzene rings. It is a component of coal tar. Anthracene is used in the production of the red dye alizarin and other dyes. Anthracene is colorless but exhibits a blue (400–500 nm peak) fluorescence under ultraviolet radiation.
Chemiluminescence 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. Here, blood is indicated by luminescence upon contact with iron in hemoglobin. When chemiluminescence takes place in living organisms, the phenomenon is called bioluminescence. A light stick emits light by chemiluminescence.
Phosphorescence is a type of photoluminescence related to fluorescence. When exposed to light (radiation) of a shorter wavelength, a phosphorescent substance will glow, absorbing the light and reemitting it at a longer wavelength. Unlike fluorescence, a phosphorescent material does not immediately reemit the radiation it absorbs. Instead, a phosphorescent material absorbs some of the radiation energy and reemits it for a much longer time after the radiation source is removed.
Luminol (C8H7N3O2) is a chemical that exhibits chemiluminescence, with a blue glow, when mixed with an appropriate oxidizing agent. Luminol is a white-to-pale-yellow crystalline solid that is soluble in most polar organic solvents but insoluble in water.
A fluorophore is a fluorescent chemical compound that can re-emit light upon light excitation. Fluorophores typically contain several combined aromatic groups, or planar or cyclic molecules with several π bonds.
A gas laser is a laser in which an electric current is discharged through a gas to produce coherent light. The gas laser was the first continuous-light laser and the first laser to operate on the principle of converting electrical energy to a laser light output. The first gas laser, the Helium–neon laser (HeNe), was co-invented by Iranian engineer and scientist Ali Javan and American physicist William R. Bennett, Jr., in 1960. It produced a coherent light beam in the infrared region of the spectrum at 1.15 micrometres.
9,10-Bis(phenylethynyl)anthracene (BPEA) is an aromatic hydrocarbon with the chemical formula is C30H18. It displays strong fluorescence and is used as a chemiluminescent fluorophore with high quantum efficiency.
Diphenyl oxalate is a solid whose oxidation products are responsible for the chemiluminescence in a glowstick. This chemical is the double ester of phenol with oxalic acid. Upon reaction with hydrogen peroxide, 1,2-dioxetanedione is formed, along with release of the two phenols. The dioxetanedione then reacts with a dye molecule, decomposing to form carbon dioxide and leaving the dye in an excited state. As the dye relaxes back to its unexcited state, it releases a photon of visible light.
1-Chloro-9,10-bis(phenylethynyl)anthracene is a fluorescent dye used in lightsticks. It emits yellow-green light, used in 30-minute high-intensity Cyalume sticks.
Bis[2,4,5-trichloro-6-(pentyloxycarbonyl)phenyl]oxalate is an organic compound with the formula (C5H11O2CC6HCl3O)2C2O2. A white solid, it is classified as a diester of oxalic acid. It is an active ingredient for the chemiluminescence in glowsticks. It can be synthesized by reacting 2-carbopentoxy-3,5,6-trichlorophenol with oxalyl chloride.
2-Chloro-9,10-bis(phenylethynyl)anthracene is a fluorescent dye used in lightsticks. It emits green light, used in 12-hour low-intensity Cyalume sticks.
Electrochemiluminescence or electrogenerated chemiluminescence (ECL) is a kind of luminescence produced during electrochemical reactions in solutions. In electrogenerated chemiluminescence, electrochemically generated intermediates undergo a highly exergonic reaction to produce an electronically excited state that then emits light upon relaxation to a lower-level state. This wavelength of the emitted photon of light corresponds to the energy gap between these two states. ECL excitation can be caused by energetic electron transfer (redox) reactions of electrogenerated species. Such luminescence excitation is a form of chemiluminescence where one/all reactants are produced electrochemically on the electrodes.
Peroxyoxalates are esters initially formed by the reaction of hydrogen peroxide with oxalate diesters or oxalyl chloride, with or without base, although the reaction is faster with base:
Fluorescence is used in the life sciences generally as a non-destructive way of tracking or analysing biological molecules. Some proteins or small molecules in cells are naturally fluorescent, which is called intrinsic fluorescence or autofluorescence. The intrinsic DNA fluorescence is very weak.Alternatively, specific or general proteins, nucleic acids, lipids or small molecules can be "labelled" with an extrinsic fluorophore, a fluorescent dye which can be a small molecule, protein or quantum dot. Several techniques exist to exploit additional properties of fluorophores, such as fluorescence resonance energy transfer, where the energy is passed non-radiatively to a particular neighbouring dye, allowing proximity or protein activation to be detected; another is the change in properties, such as intensity, of certain dyes depending on their environment allowing their use in structural studies.
The molecular formula C30H17Cl (molar mass: 412.91 g/mol) may refer to:
TCPO, or bis(2,4,6-trichlorophenyl) oxalate, is a chemical used in some types of glow sticks and is a key chemical in many chemiluminescent reactions. TCPO is classified as damaging to human organs and toxic if inhaled with an inhalable toxicity of 3.02 mg/L and oral toxicity LD50 of 820 mg/kg (rat). Additionally, TCPO is considered a danger to drinking water if even small quantities leak into the ground, and if spilled it is recommended to soak up with wood chips or absorbent material then disposing of as hazardous waste.
2-Chloro-9,10-diphenylanthracene is a fluorescent dye used in glow sticks for a blue-green glow. It is a chlorinated derivative of 9,10-diphenylanthracene.
Glowmatography is a laboratory technique for the separation of dyes present in solutions contained in glow sticks. The chemical components of such solutions can be chromatographically separated into polar and nonpolar components. Developed as a laboratory class experiment, it can be used to demonstrate chemistry concepts of polarity, chemical kinetics, and chemiluminescence.
infrared lightstick.