Wanabee
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Chemoluminescence
Hi all.
I'm trying to find the method to a reaction I once witnessed.
Chemicals(tm) were mixed in a round-bottom flask. Shaken; the mixture produced a dim glow which eventually subsided. Shaken again; the glow began
anew.
I suspect that the reaction separate back into its orginal constituents when it runs out of energy, but can't find any sign of it.
Thanks in advance,
Renaud
EbC: Title & removed Acidtests ramblings.
[Edited on 21-9-2006 by chemoleo]
Before enlightenment; I cut wood and carried water.
After enlightenment; I cut wood and carried water.
- Zen saying.
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vulture
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What you are describing is chemoluminescence (sp?).
The light comes from excited electrons which fall back.
A few classical examples:
- chlorine gas in H2O2 (bright glow)
- luminol, H2O2 and Fe
One shouldn't accept or resort to the mutilation of science to appease the mentally impaired.
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I am a fish
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White phosphorous reacting with air is another possibility.
Do you have any more information? What did the chemical(s) look like? What colour was the glow? Where did the demonstration take place?
1f `/0u (4|\\| |234d 7|-|15, `/0u |234||`/ |\\|33d 70 937 0u7 /\\/\\0|23.
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guaguanco
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| Quote: | Originally posted by Wanabee
Hi all.
I'm trying to find the method to a reaction I once witnessed.
Chemicals(tm) were mixed in a round-bottom flask. Shaken; the mixture produced a dim glow which eventually subsided. Shaken again; the glow began
anew.
I suspect that the reaction separate back into its orginal constituents when it runs out of energy, but can't find any sign of it.
Thanks in advance,
Renaud |
The classic experiment is the oxidation of Luminol (2-amino 1,4 phthalhydrazide) with H2O2. Aryloxalate esters are used in glowsticks. See this link:
chemiluminescence
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YT2095
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this May be the wrong thread, but I`m interested in Chemiluminescece also.
I have 100g of Fluorescein (almost top of the list as me Fave chem), is there any way to Make this material exhibit "glow-in-the-dark" properties?
it`s the Free Acid type I have.
Idealy I`de like to have it done and "Perfected" by Halloween 
\"In a world full of wonders mankind has managed to invent boredom\" - Death
Twinkies don\'t have a shelf life. They have a half-life! -Caine (a friend of mine)
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tumadre
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quick newbie question first:
is the CL2 / H2O2 a reaction or a catylist for heat energy to emit light?
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12AX7
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How can heat energy emit light (presumably, you imply black body radiation) when saturated with *water*?
The reaction has to do with spin states of oxygen.
Tim
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ethan_c
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What comes to mind immediately for me is an exhibit we had at a museum I worked at.
We had erlenmeyers filled with liquid in a 'shaker,' that were glowing because of aerobic, fluorescent bacteria. If you pressed a button, the shaking
stopped, the oxygen stopped dissolving as rapidly in the water, and the glow subsided, eventually disappearing. If you let go of the button, the
shaking commenced, and the glow began anew. The bacteria and sugar solution needed to be changed every few days, but the liquid was just clear- not a
complex culture or something.
It was my understanding that Luminol and the like glowed nicely for a few seconds/minutes in aquo and then winked out- shake it, and you might get a
little weak glow as the reagents were fully mixed, but it didn't keep on glowing every time you shook it.
Anyways, this might be completely different. But sure sounds similar…
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woelen
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@tumadre : Cl2/H2O2 is a real chemical reaction. Singlet oxygen is formed, which also has formula O2, but with a different electronic configuration.
When this is transformed to normal O2, then a photon is emitted. This reaction gives weak red glow. A MUCH better effect is obtained, when you add
some solid sodium dichloroisocyanuric acid (Na-DCCA) to 30% H2O2. That is quite spectacular. It also works with trichloroisocyanuric acid (TCCA), but
not so well. It also works with Ca(ClO)2, but that latter reaction is very violent, so be careful.
@YT2095: Try using a UV-LED in combination with the fluorescein in a dark room. I bet that will give quite spectacular results. Making clothes with a
solution of some of this stuff in it, and a UV-LED nearby should give a nice spooky glow in the dark. With some handyness you can construct such a
thing.
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tumadre
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thanks.
I'll try the addition of Ca(Cl0)2
i was not thinking of a black body type radiation but a reversible equasion where cem. XY split/combine at temp A and combine/split again at temp B,
so the natural distribution of molecular speeds would allow a sutable gap between the two molecular temperatures and therefore provide continual
photon production, with heat energy driving it.
but I doubt such a mix exists 
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Nicodem
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| Quote: | Originally posted by ethan_c
...but it didn't keep on glowing every time you shook it. |
A bit off topic, but there is also the phenomena of triboluminescence where mechanical forces on certain crystalline matters cause them to emit light. I know some rare earth complexes exhibit quite
strong triboluminiscence (for example, see US6117574).
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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matei
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Here's a nice review on chemiluminescence. Enjoy!
http://rapidshare.de/files/35341229/chemiluminescence.pdf.ht...
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Waffles
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| Quote: | Originally posted by Nicodem
| Quote: | Originally posted by ethan_c
...but it didn't keep on glowing every time you shook it. |
A bit off topic, but there is also the phenomena of triboluminescence where mechanical forces on certain crystalline matters cause them to emit light. I know some rare earth complexes exhibit quite
strong triboluminiscence (for example, see US6117574). |
As does uranyl nitrate. Hammer + plastic baggies + clumpy, old UO2(NO3)2 = nice greenish flashes. I figured, if I was going to powder it up anyways,
might as well do it in style!
\"…\'tis man\'s perdition to be safe, when for the truth he ought to die.\"
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YT2095
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there are a few good ones here also: http://www.chem.leeds.ac.uk/delights/texts/
experiment #26 is quite charming 
I expect at least One of the experiments shown here will be what you`re after.
\"In a world full of wonders mankind has managed to invent boredom\" - Death
Twinkies don\'t have a shelf life. They have a half-life! -Caine (a friend of mine)
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jon
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those glow sticks use a combination of glucose and a base (NaOH) I think.
when the stick is snapped base is released in the solution and chemiluminescence occurs.
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indigofuzzy
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Jon,
I would guess it has to be more complicated than that. Unless that means i could mix red devil lye with glucose and make my own glow sticks. That
would be really cool. But somehow it sounds too good to be true.
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not_important
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I thought that glowsticks used phenyl oxalate and hydrogen peroxide, plus a dye.
Ah, these folk seem to believe them same
http://chemmovies.unl.edu/chemistry/dochem/DoChem113.html
Edit - but Wiki sez that a related, substituted phenol is used for the oxalic ester
http://en.wikipedia.org/wiki/Lightstick
[Edited on 6-10-2006 by not_important]
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woelen
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| Quote: | Originally posted by indigofuzzy
Jon,
I would guess it has to be more complicated than that. Unless that means i could mix red devil lye with glucose and make my own glow sticks. That
would be really cool. But somehow it sounds too good to be true. |
You're right, it is not true...
There is, however, a very nice chemiluminiscence reaction, which can be done with easy to obtain chems. Take 5 ml of 30% H2O2, take 500 to 1000 mg of
Na-DCCA (pool chlorine granulate, shock treatment, chemical name is sodium dichloroisocyanurate, or sodium dichloro isocyanuric acid) and add the
solid to the H2O2 at once. You get a beautiful red light for approximately 30 seconds. It is a very fuzzy light, which is in the gas phase,
immediately above the liquid. I made a picture of this:
This is a very cool experiment and it is really easy to perform. This experiment also works with solid Ca(ClO)2, calcium hypochlorite, but be careful
with that. The reaction is extremely violent, and the glow only lasts for a few seconds. With TCCA it hardly works. Apparently, the TCCA is not
sufficiently soluble. It might work with TCCA + NaOH, but I did not try that.
When you do this experiment, do it in a well-ventilated room. The amount of chlorine, formed in the reaction is not very high, but it is quite smelly
and somewhat irritating.
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rotwang
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I remember a wierd wierd chemoluminesce reaction with solid diazonium compounds before they explode. for about 30seconds to a minute before they
explode there is a blue glow in the air or gas above them. it doesn't seem to be due to nitrogen.
diphenyl diazo methane is the safest on to investigate.
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Armistice19
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Is there any way to create a chemiluminiscence reaction that lasts longer than 30 seconds with easy to obtain materials? And No I'm not going to break
open a bunch of glow sticks and mix the contained reactants because thats cheating. I'm willing to synthesize my own sensitizers if at all
realistically possible. I rememeber watching Fight Club way back in middleschool and being overjoyed as my ultimate hero Tyler Durden mixed his own
chemiluminiscence formula over the stove of his abandoned house. It would be my greatest accomplishment to achieve the same goal in a simplistic and
minimalistic manner. Is this possible?
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cbfull
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I researched this subject once before to find out if luminol is actually used in glowsticks, and if so, how do they glow so long?
They actaully have some rather exotic compounds that I couldn't even google without getting the same web page. I don't know if they developed the
compound or have exclusivity with a supplier or what.
I have tried to open several glowsticks to react them in a beaker, but I diluted it slightly with methanol because it's actually not easy to get all
the liquid out (very viscous), and it drastically reduced the glow. I suppose I could have tried to evaporate the methanol but I was too disappointed
to mess with it anymore.
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