Triboluminescence is an optical phenomenon in which light is generated through breaking of chemical bonds in material when pulled apart, torn, scratched, crushed, or rubbed (see tribology). This phenomenon is not fully understood, but seems to be caused by the separation and reunification of electrical charges. This term is derived from the Greek ??????? ("to rub"; see tribology) and Latin lumen (light). Triboluminescence can be observed when breaking the sugar crystals and peeling the adhesive tape.
Triboluminescence is often used as a synonym for fractoluminescence (a term sometimes used when referring only to light emitted from cracked crystals). Triboluminescence differs from piezoluminescence in piezoluminescent materials emitting light when it changes shape, as opposed to broken. This is an example of mechanoluminescence, namely the luminescence produced from every mechanical action on solids.
Video Triboluminescence
History
Uncompahgre Ute Indians
Indian Uncompahgre Ute of Central Colorado is one of the first groups documented in the world credited with the application of mechanoluminescence involving the use of quartz crystals to produce light. Ute built a special ceremonial ceremonial made of raw buffalo leather that they filled with the clear quartz crystals that were collected from the mountains of Colorado and Utah. When the rattle is shaken at night during the ceremony, the friction and mechanical pressure of the quartz crystals have a mutual effect of producing a flash of light visible through the invisible buffalo skin.
More information
The first recorded observation was associated with the English scholar Francis Bacon when he recorded in 1620 Novum Organum that it is known that all the sugar, whether candied or plain, if difficult, will glow when broken or scratched in the dark. "Scientist Robert Boyle also reported some of his work on triboluminescence in 1663. In the late 1790s, sugar production began to produce finer sugar crystals. These crystals are formed into large cones for transportation and sales. These solid sugar cones must be broken into pieces that can be used using a device known as sugar. People are beginning to notice that when the sugar is "dribbled" in low light, small light bursts are seen.
An important example of triboluminescence occurred in Paris in 1675. Astronomer Jean-Felix Picard observed that his barometer shone in the dark when he brought it. The barometer consists of a glass tube partly filled with mercury. Whenever mercury glides on the glass tube, the empty space above the mercury will glow. While investigating this phenomenon, the researchers found that static electricity can cause low-pressure air to shine. This discovery reveals the possibility of electric lighting.
Maps Triboluminescence
Action mechanism
The material scientist has not yet reached a full understanding of its effects, but the current triboluminescence theory - based on crystallography, spectroscopy, and other experimental evidence - is that on asymmetric material fractures, the charge is separated. When the charge recombines, the electric current ionizes the surrounding air, causing flashes of light. Further research has shown that crystals that exhibit triboluminescence should be less symmetrical (thus becoming anisotropic to allow charge separation) and become poor conductors. However, there are substances that violate this rule, and which have no asymmetry, but display triboluminescence as well, such as hexakis (antipyrine) terbium iodide. It is estimated that these materials contain impurities, which give the nature of the asymmetry to the substance.
The biological phenomenon of triboluminescence is conditioned by free radical recombination during mechanical activation.
Example
Diamonds can start to glow when rubbed. This sometimes occurs in diamonds when the sides are being milled or the diamond is sawn during the cutting process. Diamonds can be blue or red. Some other minerals, such as quartz, are triboluminescent, emitting light when rubbed together.
Regular Pressure-sensitive tape ("Scotch tape") displays a glowing line where the end of the ribbon is pulled away from the scroll. In 1953, Soviet scientists first observed that unrolled recording in a vacuum that produced X-rays. The mechanism of X-ray generation was studied further in 2008. Similar X-ray emissions have also been observed with metals.
Also, when the sugar crystals are destroyed, a small electric field is created, separating the positive and negative charges which then create a spark when trying to reunite. Wint-O-Green Life Savers works very well for creating such sparks, because wintergreen oil (methyl salicylate) is fluorescent and converts ultraviolet light into blue light.
Triboluminescence is a biological phenomenon observed in the mechanical deformation and electrical contact of epidermal surfaces of soft and osseous tissue, in chewing foods, in friction of the joints of the vertebrae, during intercourse, and during blood circulation.
Fractoluminescence
Fractoluminescence is often used as a synonym for triboluminescence. This is the light emission from the fracture (not rub) of the crystal, but fractures often occur by rubbing. Depending on the composition of the atoms and molecules of the crystal, when a fragment of the crystal separation of charge can take place one side of the cracked crystal is positively charged and the other side is negatively charged. As in triboluminescence, if the charge separation generates considerable electrical potential, the discharge in the gap and through the inter-interface bath gas can occur. The potential in which this occurs depends on the dielectric properties of the bath gas.
EMR propagation during fractures
Electromagnetic radiation emissions (EMR) during plastic deformation and crack propagation in metals and rocks have been studied. EMR emissions from metals and alloys have also been explored and confirmed. Molotski presented a dislocation mechanism for EMR emission types. Recently, Srilakshmi and Misra reported additional phenomenon of secondary EMR during plastic deformation and crack propagation in metallic and non-coated metal alloys and coated metals.
Theory
EMR during micro-plastic deformation and crack propagation of some metals and alloys and the formation of a temporary magnetic field during necking on the ferromagnetic metal was reported by Misra (1973-75), which has been confirmed and explored by several researchers. Tudik and Valuev (1980) were able to measure EMR frequencies during fracture of iron and aluminum in the region of 1014Ã,¬Ã, Hz using photomultipliers. Srilakshmi and Misra (2005a) also reported additional phenomena of secondary electromagnetic radiation on metal and metal alloys that are not coated and coated with metals. If solid materials are subjected to large amplitude pressures, which can cause plastic deformation and fracture, emissions such as thermal, acoustic, ion, exo emissions occur. With the invention of new materials and advances in instrumentation to measure the effects of EMR, the formation of cracks and fractures; EMR emission effects are important.
Generation X-Rays
In a moderate vacuum, peeling the tape produces enough X-rays for human x-ray fingers.
Deformation induces EMR
The study of deformation is essential for the development of new materials. Deformation of the metal depends on the temperature, type of applied stress, strain rate, oxidation and corrosion. Deformation caused by EMR can be divided into three categories: effects in ionic crystals; effects in rocks and granites; and, effects on metals and alloys. EMR emissions depend on the orientation of the grains in individual crystals because the properties of the material differ in different directions. The amplitude of the EMR pulses increases as long as the crack continues to grow because the new atomic bond is broken and leads to the EMR. The pulse begins to rot when the crack stops. Observations from experiments show that emitted EMR signals contain mixed frequency components.
Test method to measure EMR
The most extensive tensile test method is used to characterize the mechanical properties of the material. From each complete tensile test, one can obtain important information about the elastic properties of the material, the character and the degree of plastic deformation, yield and tensile strength and toughness. This information can be obtained from a single test justifying the extensive use of tensile tests in the research of engineering materials. Therefore, EMR emission investigations are primarily based on specimen tensile tests. From the experiment, it can be shown that the tensile crack formulation excites the EMR more intensively than the shear fracture, increasing the elasticity, strength and loading rate during uniaxial loading increases the amplitude. Poissons ratio is the key parameter for EMR characterization during triaxial compression. If the filter ratio is lower, it is more difficult for the material to overload transversely and therefore higher is the possibility of a new fracture. The mechanism of plastic deformation is essential for the safe operation of any component under dynamic conditions.
Usage and app
This EMR can be used in developing smart sensors/materials. This technique can be implemented in powder metallurgy techniques as well. EMR is one of the emissions that accompany large deformations. If an element can be identified that provides a maximum EMR response with minimum mechanical stimulus then it can be incorporated into the main material and thus establishes a new trend in the development of intelligent materials. Deformation caused by ESDM can serve as a powerful tool for detection and prevention of failure.
Orel V.E. find a device to measure the entire EMR of blood and lymphocytes in laboratory diagnostics.
See also
- Piezoelectric
- Earthquake light
- List of light sources
- Sonoluminescence
References
Further reading
- MartÃÆ'n Gil, JesÃÆ'ºs; MartÃÆ'n Gil, Francisco J. (1978). "Triboluminescence of new uranium salt". Chemical Education Journal . 55 (5): 340. Bibcode: 1978JChEd..55..340G. doi: 10.1021/ed055p340.
- Sweeting, Lind M. (Sep 1998). "Wintergreen Candy and Other Triboluminescent Materials". Chemistry Department . Scientific Experiments at Home. University of Towson.
External links
- "Sound Science Behind Glowing Sugar". World of Physics . 2006.
- "Correlations between nanosecond X-ray flashes and slip-sticky friction on stripped bands". Nature . 455 : 1089-1092. 23 Oct 2008. Bibcode: 2008Natur.455.1089C. doi: 10.1038/nature07378.
- Triboluminescence Discussion on Tribo Net
- Create a Duct Tape Glow on YouTube (2010)
Source of the article : Wikipedia
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