Wh Mia Foust Mr. Dunlap Honor Chemistry, Per 7 December 21, 2010 Glow Sticks Since glow sticks have been invented, consumers have wondered how scientists are able to create these magical sticks of light. They work without producing heat.
They don’t need a battery or a bulb, Magic? This “cool” light is called luminescence. Unlike incandescence, which is light from heat energy, luminescence can be emitted at normal or lower temperatures.
There are several types of luminescence, bioluminescence, is what happens in fireflies: as the “bio” prefix indicates, it’s caused by a chemical reaction in living things, cathodoluminescence, is caused by electron beams. And Chemiluminescence. Chemilumiescence is the magic behind the glow stick. Chemiluminescence is what happens in glow sticks. The energy that is needed is supplied by chemical reactions. The chemical reaction of chemiluminescence releases energy that is absorbed by electrons in molecules. Electrons in the atoms make a quantum leap once they absorb the energy from the reaction.
The electrons must either jump to or fall back from one quantum level to another quantum level this is the quantum leap. (1) The electron jumps to a higher level; at this point the electron is in what is called the excited state, or a higher quantum. As the electron returns to the lower state, it releases the energy as a photon of light; the photon is the light that we see. To make this easier to understand, think of a rock being picked up. When a person picks up a heavy rock, it takes energy, just as it takes energy for an electron to jump to a higher energy level.
When the person drops the rock and it falls to the ground, the energy is released as sound energy. And in the case of the electron, the energy that is released is light energy instead of sound energy. Planck’s equation, E = hv was created by Max Planck and Albert Einstein. The equation relates the energy of a Quantum leap “E” to the frequency, or color of the light that is given off “v”. Chemists have been fascinated with “cold light” for as long as there have been fireflies flying around the night skies. In the first steps to making their very own “cold light,” they knew what was equired: a molecule that radiates light when it is excited and an energy source to excite that molecule. In the early 1960s, a young chemist by the name of Edwin A. Chandross was looking for a way to describe chemiluminescence. Chandross knew that peroxides had a large amount of potential energy. He concluded that they were likely to be participants in the future of chemiluminescence. In his work, Chandross was able to produce a reaction that produced a “cold light”. However, it wasn’t very efficient. Although Chandross’s work wasn’t efficient, it was a major step in the right direction for chemiluminescence. Edwin A.
Chandross didn’t realize that his discovery had great potential. Sadly he never patented it. Around the same time, another chemist by the name of Michael M. Rauhut began studying some of Chandross’s work. Rauhut and his team began searching for a reaction that would be powerful enough to be practical to use. Eventually they designed a phenyl oxalate ester that, when mixed with hydrogen peroxide and a fluorescent dye, produced a reaction not quite as efficient as a firefly. The group called it Cyalume, which became its name when Rauhut’s company, American Cyanamid, began selling it as one of their chemical light products.
The basic structure of a glow stick is particularly simple. It contains the somewhat bendable plastic outer shell and the easily broken inner glass vial. When the glow stick is ready to be used, an individual will grip each end of the glow stick and bend it. As the flexible external plastic casing of the glow stick begins to bow, it comes in contact with the internal glass vial, and begins to apply pressure to it. Because the inner glass vial is less flexible than the plastic, it will fracture sooner than the outer plastic. The outcome is that the glass vial breaks and spills its contents into the larger compartment of the glow stick.
It is the breaking of the glass vial that gives glow sticks their distinctive snapping noise when activated. When the glass vial is broke. The contents are able to mingle and react with the liquids in the main compartment. The chemical reaction begins and the glow stick lights up. (2) Refer to Figure 1. The outer compartment contains fluorescent dye and phenyl oxalate ester. Floating inside that solution is the small glass vial that contains hydrogen peroxide. When the phenyl oxalate ester and the hydrogen peroxide are mixed, it creates a reaction that produces peroxyacid ester. The Peroxyacid ester then decomposes to create carbon dioxide.
This releases energy that excites the electrons in the florescent dye and causes them to jump to a higher energy level. Then as the dye becomes less excited, it releases energy, and the electrons produce light as they drop back down to a lower energy level. (3) Examine figure 2. Glow stick products usually last anywhere from 4 – 10 hours at normal temperatures. A change in temperature will cause the stick to glow brighter or longer. Normally the particles travel at a slow speed; however an increase in temp will increase the heat/energy and cause the particles to travel faster and collide with greater force.
Chemical reactions cause chemical bonds to be broken and then reformed between different atoms, creating new substances. (4) Companies often tell consumers to pop their glow sticks into the freezer to keep it glowing longer. This is because the lower temperatures slow down the reaction rate. Particles move slower and collide less, making the reaction slower at lower temperatures. The amount of time the glow stick lasts also depends of the color of the dye. Reds and greens last the longest, while blues through pinks last a shorter amount of time. See figure 3. Glow sticks have many practical and recreational uses.
People are thinking of new uses for glow sticks and glow light products every day. Along with being used for entertainment and fun, glow sticks can be used for safety purposes. For instance glow sticks have contributed to helping many through natural disasters, search and rescue, and they are even used a great deal by military members. Glow sticks have been used in the military since 1962. The military has found a variety of uses for glow sticks including non-tactical military ops, safety, and night operations. The military uses glow sticks for night missions, and safety, to keep track of others.
The military uses glow sticks also for non-tactical military ops, by marking others movements, and the trails that are to be traveled. Now glow sticks are put into all standard issue military safety kits. They have found they are very useful and are a lightweight, low hazard, and easy to store. The military issues about 15 million glow stick units a year. (5) Civilians use glow sticks for recreation and fun. Consumers use them for activities such as camping, fishing, hunting, fans wear them at concerts, and children wear them to be cool at fairs and carnivals.
Because of their size, convenience, price, and safe to use anywhere source of light, glow sticks are a product nearly everyone enjoys. Many boaters use glow sticks for nighttime cruses to keep track of one another on the water. The most popular type of glow stick is the standard six-inch stick, and the most popular color is green because it last the longest. There are many stories where glow sticks have contributed to saving peoples lives in search and rescue missions. When people are lost and being searched for and they have a glow stick they can be found more easily in the dark. Glow sticks are truly magic in their own way.
They have helped many in different ways. Scientist like Chandross and Rauhut, who have helped pave the way for increased safety measures for men and women in uniform, and who help adoring fans create ambiance at concerts should be thanked. Figure 1 (6) Figure 2 (7) [pic] Figure 3 (8) [pic] Work Cited Cool Blue Light Experiment Kit. 1996, 16-17 (1) How Chemical Glow sticks work. http://glowgranny. com/articles/ chemical_glow_sticks_working. htm. 11/25/10 (2) Huang, Jason. Customer Service Rep, Happy Glow. jason. [email protected] com 11/25/10. “interview” (3) Using heat to speed up reactions in the kitchen http://www. ynami cscience. com. au/tester/solutions/chemistry/juniorsciencefoodchem/homechemistry1. htm. 12/1/10 (4) History of glow sticks in the military www. militaryglowsticks. com/pages/history-of-glow-sticks-in-the-military. html 11/25/10 (5) User and Applications. http://jeanbont. pbworks. com/w/page/23323157/Applications 12/19/10 (6) Reactions. http://www. engin. umich. edu/~cre/web_mod/new/glowsticks/reactions. htm 11/25/10 (7) Extreme glow http://www. extremeglow. com/Merchant4/ merchant. mvc? Screen=CTGY&Category_Code=Helpful_Photo. 11/23/10 (8) ———————– 08 Fall Mia Foust Glow Sticks