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Stuff that Glows

Page history last edited by PBworks 12 years, 10 months ago

Stuff that Glows

 

  • Fluorescence - UV
  • Phosphorescence - Glow in the Dark
  • Chemiluminescence - Glowsticks

 

 

 

Fluorescent Things

  • Tonic Water (Quinine)
  • Washing Powder (Optical Brighteners)

 

  • Fluorophores -- Fluorescent Dyes
    • Fluorescein
    • Fluorescent Ink

 

 

Phosphorescent Things

 

 

Chemiluminescent Things

  • Glowstick Chemicals

 

 

 

 

10. What chemicals are in a glow light?

The glow light is made of two parts which when mixed together create the chemical reaction which makes them glow.

 

4 g sodium carbonate

0.2 g luminol

0.5 g ammonium carbonate

0.4 g copper sulfate pentahydrate

approx. 1 litre of distilled water.

50 ml of 3% hydrogen peroxide

approx. 1 litre of distilled water

Wikipedia

The glowstick contains two chemicals and a suitable fluorescent dye (sensitizer, or fluorophor). The chemicals in the plastic tube are a mixture of the dye and a derivate of phenyl oxalate ester (also called Cyalume). The chemical inside the glass vial is concentrated (about 35%) hydrogen peroxide. By mixing the peroxide with the phenyl oxalate ester, a chemical reaction takes place; the ester is oxidized, yielding two molecules of phenol and one molecule of peroxyacid ester. The peroxyacid decomposes spontaneously to carbon dioxide, releasing energy that excites the dye, which then deexcites by releasing a photon. The wavelength of the photon depends on the structure of the dye.

 

 

Other chemicals are usually present in the mixture as well; eg. sodium salicylate as a catalyst, and bis(2-ethylhexyl) phthalate (DEHP) as a solvent. Instead of cyalume, bis(2,4,5-trichlorophenyl-6-carbopentoxyphenyl)oxalate (CPPO) is used in practical formulations, as it gives significantly better quantum yield. A similar reaction can be achieved with bis(2,4,6-trichlorophenyl)oxalate (TCPO).

 

 

Cyalume + H2O2 + dye → phenol + 2 CO2 + dye*

the most efficient non-enzymatic reaction known

 

Luminol + Oxidiser (eg Hydrogen Peroxide/OH-) + Catalyst (eg: Iron or Copper) = Light!

 

Bioluminescence:

ATP + Luciferin + Luciferase --> intermediate complex

+ Oxygen --> !!!

 

 

HoP

UV (ultra violet) is a portion of the electromagnetic spectrum just past violet which is at the short wavelength end of visible light as seen by the human eye. UV can not be seen by the human eye, but when it falls on certain materials it may cause them to become fluorescent (ie. glow) and reflect visible light back to our eyes.

 

There are 3 different types of UV light

 

UVA (315-400nm) is commonly known as "black light". This is fairly safe UV light.

UVB (280-315nm) is dangerous with overdose and will cause the skin to burn and blister.

UVC (100-280nm) is very dangerous and is mostly blocked from the sun by the earth's atmosphere .

 

 

Fluorescent lighting tubes generate UVA and the powder on the inside surface of the glass tube becomes fluorescent and glows to produce a very efficient form of lighting.

 

Fluorescent tubes in dance clubs have a special glass coating so only the safe part of UVA "black light" is transmitted into the room, making only some items become fluorescent and glow extra brightly.

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