CHEMILUMINESCENCE

CHEMILUMINESCENCE

By: Mark DavidsonStephen Au

Benjamin Wong

WHAT IS IT?

Is the production or emission of light as a direct by-product of a chemical reaction. This light is often referred to as “cold light” because almost no heat is produced as a result of the reaction.

Chemiluminescence :

HOW DOES IT WORK?

Chemiluminescence occurs when chemicals are mixedtogether and as a result creates a direct by-product of light.The chemical compound that produces the light is “excited”by the energy created in the chemical reaction. The chemicalcompound, once the reaction is finished, tries to attain itsoriginal energy state, and in that process, must release theenergy created in the reaction. This energy is released in theform of light.

How is it used? Where and when is it used?

• It is used for entertainment, practical and scientific uses. • In crime scenes, Luminol is used for forensics to create a chemiluminescene

reaction to determine if traces of blood are at the crime scene or not.• Glow sticks are used for many purposes. They are waterproof, do not use batteries,

generate no heat, are inexpensive, and are reasonably disposable. • They can tolerate high pressures, such as those found underwater. They are used

as light sources and light markers by military forces, campers, and recreation diving doing night diving.

• Glow sticks are considered the 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 sparking.

• Glow sticking is the use of glow sticks in dancing. This is one of their most widely known uses in popular culture as they are frequently used for entertainment at parties (particularly raves), concerts and dance clubs.

Example Pictures

Blood TestingChemiluminescence is used in the blood testing industry. In this

process, blood serum (reactant) and reagents (reactant) are mixed together to create a chemical compound. As a result of this reaction, light is emitted. Unlike chemiluminescence created in glow sticks, this reaction produces a very minute amount of light. A photo multiplying tube is used to determine the amount of light emitted (the photo multiplying tube amplifies the amount of light to a recordable level). The concentration of a certain chemical in the serum is directly linked to the amount of light emitted by the reaction (the type of chemical in the serum that is measured is determined by the reagents used). This process can be used to find out many things, such as tumor markers and hormones.

Glow sticks

• A glow stick is a single-use translucent plastic tube containing isolated substances which when combined make light through a chemical reaction induced chemilluminscence which does not require a power source to function.

• When the hydrogen peroxide reacts with phenyl oxalate ester (oxidizing it), a glow is produced and the color is based on the fluorescent dye also in the stick.

Rescue

• Some chemiluminescent systems work by reacting with oxygen in the atmosphere. These chemiluminescent systems are sealed with many things, such as tape. It may also be stored in a plastic tube. Once these “covers” are removed, the chemiluminescent systems react with the oxygen in the atmosphere and emit light. These chemiluminescent systems are bright enough for a camera to take a photo without using a flash, and therefore, are a great tool to mark exit’s in electrical failures, for sea and air rescues, and any kind of emergency situation

• Chemiluminscence is seen in use in forensics. Luminol, a chemical, is sprayed onto the areas where the crime scene occurs. The luminol then reacts with iron in the blood. This only works in a dark room. When it is dark, you can see the light emitted by this reaction. This helps people in forensics a lot, and is popularized by shows such as CSI.

FORENSICS USE CHEMILUMINSCENCE

Works CitedStedman, Donald H. "Chemiluminescence - Chemistry Encyclopedia -

Structure, Reaction, Water, Uses, Gas, Molecule." Chemistry: Foundations and Applications. Web. 17 Apr. 2011.

<http://www.chemistryexplained.com/Ce-Co/Chemiluminescence.html>.Nelson Education Ltd. "Earth's Climate System and Natural Change &

Earth's Climate: Out of Balance." Nelson Science Prespectives 10. Toronto, Ont.: Nelson Education, 2010. 473-474. Print.

White, Charles. "Chemiluminescence." Encyclopedia Americana. Grolier Online, 2011. Web. 17 Apr. 2011.

"The Forensic Use of Chemiluminescence and Luminol." Scribd. Web. 17 Apr. 2011. <http://www.scribd.com/doc/8712808/The-forensic-use-of-

Chemiluminescence-and-Luminol>.Smith, S. E. "What Is Chemiluminescence?" WiseGEEK: Clear Answers for

Common Questions. Ed. Bronwyn Harris. Web. 17 Apr. 2011. <http://www.wisegeek.com/what-is-chemiluminescence.htm>.