Luminous paint

Luminous paint

Luminous (or luminescent) paint exhibits luminescence. In other words, it gives off visible light through fluorescence, phosphorescence, or radioluminescence.

Fluorescent paint

Fluorescent paint reacts to long-wave ultraviolet (UV) radiation, commonly known as black light. Through the mechanism of fluorescence, UV-sensitive pigments present in the paint absorb black light and give off visible light in return.

There are two basic kinds of fluorescent paint: visible and invisible. Visible fluorescent paint can appear any bright color under white light, and glows brilliantly under black light. Invisible fluorescent paint appears white or clear under white light, but glows a particular color—depending on the pigment used—under black light.

This type of paint has extensive applications in the entertainment industry, and it can be used to create black-light effects such as invisible images, dual images, day–night transitions, and 3-D effects.

Phosphorescent paint

Phosphorescent paint is commonly called "glow-in-the-dark" paint. It is made from phosphors such as silver-activated zinc sulfide or, more recently, doped strontium aluminate, and typically glows a pale green to greenish blue color. The mechanism for producing light is similar to that of fluorescent paint, but the emission of visible light persists for some time after it has been exposed to light. Phosphorescent paints have a sustained glow which lasts for some minutes or hours after exposure to light, but will eventually fade over time.

This type of paint has been used to mark escape paths in aircraft and for decorative use, such as "stars" applied to walls and ceilings. It is also increasingly used as an alternative to radioluminescent paint.

Radioluminescent paint

Radioluminescent paint contains a radioactive isotope combined with a radioluminescent substance. The isotopes selected are typically strong emitters of fast electrons (beta radiation), preferred since this radiation will not penetrate an enclosure. Radioluminescent paints will glow without exposure to light until the radioactive isotope has decayed (or the paint itself degrades), which may be many years. They are therefore sometimes referred to as "self-luminous".

Radioluminescent paint was invented in 1908 and originally incorporated radium-226. The toxicity of radium was not initially understood, and radium-based paint saw widespread use in, for example, watches and aircraft instruments. During the 1920s and 1930s, the harmful effects of this paint became increasingly clear. A notorious case involved the "Radium Girls", a group of women who painted watchfaces and later suffered adverse health effects from ingestion. It is now recognised that radium paint requires great care in application, maintenance and disposal to avoid creation of a hazardous condition.

In the second half of the 20th century, radium was progressively replaced by safer radioisotopes such as promethium-147 and later tritium. Because of safety concerns and tighter regulation, consumer products such as clocks and watches now increasingly use phosphorescent rather than radioluminescent substances. Radioluminescent paint may still be preferred in specialist applications, such as diving watches. [ [http://www.hse.gov.uk/radiation/rpnews/rpa21.htm#a11 Hazards from luminised timepieces in watch/clock repair] , UK Health and Safety Executive]

References


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Look at other dictionaries:

  • Luminous paint — Luminous Lu mi*nous, a. [L. luminosus, fr. lumen light: cf. F. lumineux. See {Luminary}, {Illuminate}.] [1913 Webster] 1. Shining; emitting or reflecting light; brilliant; bright; as, the is a luminous body; a luminous color. [1913 Webster] Fire… …   The Collaborative International Dictionary of English

  • luminous paint — noun : a paint containing a phosphor (as zinc sulfide activated with copper) and so able to glow in the dark either for a time after exposure to ultraviolet radiation or indefinitely by excitation with a radioactive material (as radium) if one… …   Useful english dictionary

  • luminous paint — šviečiantieji dažai statusas T sritis chemija apibrėžtis Zn, Ca, Ba sulfidų ar organinių liuminoforų turintys dažai. atitikmenys: angl. luminescent paint; luminous paint rus. люминесцентная краска; светящаяся краска …   Chemijos terminų aiškinamasis žodynas

  • luminous paint — paint containing a phosphor that emits visible light when irradiated with ultraviolet light. [1885 90] * * *       paint that glows in the dark because it contains a phosphor, a substance that emits light for a certain length of time after… …   Universalium

  • luminous paint —    A paint which actually glows in the dark. It contains a phosphor, which is usually a form of zinc or calcium sulfide. It stores light when exposed to it for a length of time, emitting it as a greenish or bluish glow for a relatively short… …   Glossary of Art Terms

  • luminous paint — noun Date: 1884 a paint containing a phosphor (as zinc sulfide activated with copper) and so able to glow in the dark …   New Collegiate Dictionary

  • luminous paint — /lumənəs ˈpeɪnt/ (say loohmuhnuhs paynt) noun paint which contains a phosphorescent compound and therefore glows after exposure to light …  

  • Luminous paint — Светящаяся [люминесцентная] краска …   Краткий толковый словарь по полиграфии

  • Luminous — Lu mi*nous, a. [L. luminosus, fr. lumen light: cf. F. lumineux. See {Luminary}, {Illuminate}.] [1913 Webster] 1. Shining; emitting or reflecting light; brilliant; bright; as, the is a luminous body; a luminous color. [1913 Webster] Fire burneth… …   The Collaborative International Dictionary of English

  • Luminous — may refer to:*luminosity, a scientific term referring to different things depending on the field in which it is used * Luminous (story collection), a short story collection by Greg Egan *Luminous paint, paint that glows in the dark *Luminous… …   Wikipedia

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