Presentation on theme: "Fluorescent Materials Mrs. L. Fox. What is Fluorescence? The emission of electromagnetic radiation, especially of visible light, stimulated in a substance."— Presentation transcript:
What is Fluorescence? The emission of electromagnetic radiation, especially of visible light, stimulated in a substance by the absorption of incident radiation and persisting only as long as the stimulating radiation is continued.
Fluorescent Lamps A fluorescent lamp converts electrical power into useful light more efficiently than an incandescent lamp. Lower energy cost typically offsets the higher initial cost of the lamp. They are also cooler than incandescent lights
How Does This Type of Light Differ From Regular Light Bulbs? The main difference between these sources is the process of exciting the atoms. In an incandescent light source, such as an ordinary light bulb or gas lamp, atoms are excited by heat; in a light stick, atoms are excited by a chemical reaction.
Other Things That Glow Fluorescent molecules tend to have rigid structures and delocalized electrons. Examples of common materials that MIGHT contain fluorescent molecules include: White Paper Petroleum Jelly US $20 Bill Modern US $20 bills contain a security strip near one edge that glows bright green under a black light. Tonic Water
Body Fluids Vitamins Chlorophyll Antifreeze Laundry Detergents Tooth Whiteners
Phosphorescence Is a specific type of photoluminescence related to fluorescence. It releases the radiation more slowly Example include: – glow-in-the-dark toys – Paint – clock dials
Triboluminescence Is an optical phenomenon in which light is generated through the breaking of chemical bonds in a material when it is pulled apart, ripped, scratched, crushed, or rubbed Examples: – Wintergreen candy – Ripping apart adhesive tapes
Chemiluminescence Is the emission of light (luminescence), as the result of a chemical reaction. There may also be limited emission of heat.
Bioluminescence That light that is emitted from living (or once living) organisms. This is a type of chemiluminescence. – Examples: Jellyfish Some algae (diatoms) Fluorescent fish