Saturday, May 23, 2009

Uses of Fluorescence

Fluorescence is broadly used in the world today. The most common application of fluorescence is the use of this property in fluorescent light bulbs (5).  A fluorescent light bulb consists of an evacuated glass bulb containing mercury vapor (8).  It is coated on the inside with fluorescent powder.  These powders are known as phosphors and contain fluorescent elements such as apatite analog (Sr5(PO4)3F), antimony, and rare earth metals (8).  In the bulb, short waved UV light is emitted (5). Voltage is applied to the light bulb and mercury becomes ionized to conduct electricity.  The electron of the mercury vapor escapes leaving a mercury ion.  The electron collides with the mercury gaseous atom, become excited, and emits this UV light (8).  The phosphors in the fluorescent powder absorb the energy and re-emit it as visible light.  This way of producing light wastes less energy because the light bulb does not become hot and does not waste its energy heating the world.  Fluorescent materials are also harnessed and implemented in bleach. In this way, laundry detergent companies can argue that their bleach is “whiter than white.”  These companies put fluorescers in their detergents in quantities of up to one per cent.  Clothing manufacturers make their clothing with fluorescers already in them.  In the bright sun, white shirts can harness the UV energy and become very white (5). Many people’s professions are mineral hunters.  Although this job sounds humorous, these skilled professionals search for valuable minerals especially ones with fluorescent properties.  They can use their mineral’s fluorescent properties to decipher the origins of the mineral.  Some diamonds are even fluorescent!  Although nowadays people regard fluorescence as an impurity in their diamonds, the green light that some diamonds produced under black light used to be regarded as highly precious (8).  More common uses of fluorescence include posters that glow in black light, cosmic bowling, and in forensic science to identify clues (5).  Fluorescence is extremely useful in many areas of our lives.  

No comments:

Post a Comment