Triboluminescence materials

Literature reports of crystal space groups of triboluminescent materials provide evidence for a modest correlation between tribo-luminescence and noncentric space group Q5) of 36 triboluminescent inorganic sulfates (16), 21 are noncentric and 15 are centric of 19 triboluminescent aromatic organic crystals (12) of known crystal structure, 13 are noncentric and 6 are centric. Many compounds crystallize in more than one space group thus the literature crystal structures may not be relevant to the triboluminescent materials. We therefore examined samples from the same batch of crystals for triboluminescence activity and crystal structure. The results are shown in Table II, along with some related compounds (6, 12, 13) whose crystal structures were obtained from the literature. 

We would like to mention the fascinating triboluminescence239 of uranyl nitrate, where the emitted spectrum looks like photoluminescence, whereas several other triboluminescent materials crushed in nitrogen or neon give the characteristic spectra of electric discharges in the surrounding gas. 

Rare-earth diketonates incorporated into polymers that result in new triboluminescent materials have been investigated by Takada and coworkers . Although some RE + compounds exhibit no TL in powder form, the TL phenomenon has been observed when these compounds are dispersed in a polymer matrix and the TL mechanism is adduced to electron impact caused by discharge due to a high electric field arising from frictional electrification between the fihn and the substrate. 

Hollerman, W.A. Goedeke, S.M. Bergeron, N.P. Muntele, C.I. Allison, S.W. Ila, D. Effects of proton irradiation on triboluminescent materials such as ZnS Mn. Nucl. Instrum. Methods Phys. Res. in press. 

Mechanoluminescence or triboluminescence arises from the mechanical action on solids lyoluminescence is where the emission of light occurs when a material goes into solution. Thermoluminescence is observed during the heating of a solid that has previously absorbed energy from radiation, as ions trapped in the solid recombine. (See also Glossary for an explanation of the terms.)... 

Triboluminescence Mechanical shaking, rubbing or crushing Crack detection in composite materials... 

Triboluminescence is the phenomenon that is observed when coloured light is emitted on grinding, crushing or fracturing certain crystalline compounds, e.g. the bluish white light emitted from sugar. This phenomenon has been known for over 300 years but has remained a curiosity without an obvious application, until very recently when Sage postnlated that this effect could be used to detect flaws in composite materials. ... 

Triboluminescence, from the Greek word tribein (to rub) is a term used to describe the visible (and UV) emissions of materials when they are stressed to failure. This phenomenon is very common among minerals (see Table I), and is well known to spelunkers who enjoy smashing fluorite deposits to see the light. Earthquake lights (1) (2) are probably triboluminescence on a grand scale. 

The term triboluminescence is often used to describe any light emission occurring upon impact with or grinding of a crystalline material, and is certainly more than one phenomenon (3). Light emissions caused by heating during fracture, such as thermoluminescence and blackbody radiation, are common, but neither they nor chemical reactions such as oxidation are strictly considered triboluminescence they will not be discussed in this paper. 

Dissolution of inorganics from the bone leaves the tribolumi-nescence intact , dissolution of the organic material destroys the triboluminescence. Meir Lahav, personal communication. 

Materials which emit light on fracture are said to be frac-toluminescent and may be classified by their emission spectra. Nonphotoluminescent solids such as quartz, sucrose and tartaric acid have a triboluminescence spectrum indistinguishable from the 3ttu - ... 

A. L. Sweeting, L. M. unpublished study). Disorder is not common in the 9-substituted anthracenes, but is observed for anthryl esters 7 and 9. We conclude that disorder may provide local dissymmetry, deforming the lattice and allowing charge accumulation. Unfortunately crystallography cannot determine how the sites of different conformation are distributed in the crystal. We examined the local environment by testing some of the materials for the generation of a second harmonic on laser irradiation no correlation with triboluminescence was found. 

Triboluminescence (TL) is the phenomenon of light emission during the application of a mechanical stress or by fracture of crystals in a solid sample. The materials presenting this behavior are promising for application in real-time structural damage sensors . 

A wide variety of materials triboluminesce i.e., yield photon emission (phE) during fracture. Chandra and Zink (21) classify materials according to the emission... 

Found in coal tar. Dyestuff intermed. Reference material used in elemental microanalysis. Monoclinic plates (EtOH), colourless with violet fluor. when pure, dj 1.283. Mp 216.1 . Bp 339.9 . Strongly triboluminescent. 

Reference material used in elemental microanalysis. Cryst. (EtOH). Mp 89.57°. Bp 291°, Bp 302.8°, Bpj4 167°. Triboluminescent. Steam-volatile. 

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