[ghadir]

i need to learn how to make glowin dark painti find n article aboutthisbutit dosentconsistofthe formulation and
percentage of combination please help me to know

this is the article

>What are the chemicals used to create "glow-in-the dark" products?
>The kind that you expose to a light source to charge them up and then they
>emit a green glow for a while, but not really bright enough to be useful
>as a light source.
 
   You are referring to phosphors (the material) and phosphorescence
(the characteristic).  The useful lifetime of such phosphorescence for
paints is on the order of hours.
 
   Most phosphorescent paints use inorganic crystal phosphors,
which are usually mixtures of metallic sulfides and/or oxides.  Other
metals, such as bismuth and copper, may be added as "activators".
 
   A typical green phosphor found in "luminous paint" is a mixture of
zinc sulfide and cadmium sulfide.  The resultant emission spectrum shifts
toward longer wavelengths as the percentage of cadmium sulfide in the
mixture is increased.  Persistence (i.e., phosphorescence lifetime) of
such mixtures range from 1 to 10 hours.
 
   A typical blue phosphor found in luminous paint is a mixture of
calcium sulfide and strontium sulfide.  Persistence may be as long as 12
hours.
 
   In general, as the emission wavelength of a phosphor increases
(i.e., shifts toward red), persistence decreases.  While yellow and red
phosphors exist, they are not common because of the short persistence.
Cadmium sulfide, in fact, has emission energy in the near-IR region.
 
>Also, does anybody know why they only seem to come in green...I have never
>seen red or blue or....etc
 
   See above reason for lack of persistence at red wavelengths.
Blue pigments are not as common as green since the human eye is much more
sensitive to green wavelengths.
 
>The other kind of luminous stuff is in light sticks. (A plastic tube
>containing two chemicals - one in a glass vial - which you have to
>bend to break the glass and shake.)  The resulting chemical reaction
>emits a very bright glow for ~2-3 hrs.  I have seen these in green and blue.
 
   You are probably referring to the chemiluminescent lightsticks
manufactureed by American Cyanamid under the tradename "Cyalume".  While
I don't know the exact ingredients in the Cyalume product, I can give
you a clue.
 
   Chemiluminescence is exhibited by many cyclic hydrazides when such
are oxidized in the presence of a strong base.  The resultant light is
emitted due to excitation of the amino-phthalate dianion.  The most
common example of a suitable cyclic hydrazide is o-aminophthalylhydrazide
(I'll pass on the IUPAC for the moment), better known as luminol.
 
   The luminol loses the hydrogens from the hydrazide groups due to
the -OH radicals from the strong base.  The oxidizing agent knocks out
the nitrogens (liberating elemental nitrogen), destroying that ring, and
creating the amino-phthalate dianion.
 

[RyanJones]

Funny, you can also use Phosphorus in some cases but in most its pure form is too reactive :-)

Cheers,

Ryan Jones

[P]

i need to learn how to make glowin dark painti find n article aboutthisbutit dosentconsistofthe formulation and
percentage of combination please help me to know

If it's a formulation you want you need to be a bit more specific  -   does it need to be an external paint?   Does it need to be waterbased?  etc..

Most paints follow a similar formulation code unless they need to be 'funky' like protect from fire or corrosion or whatever.

Binder   (polymer dispersed in water or disolved in solvent)
solvent  /  carrier   (solvent or water)
Pigments (for coulour)
filler  (bulking)
Surfactants and dispersing agents.


For a waterbased flouresent paint try playing with the following rather losely untill you get something like your looking for:

Waterbased polymer dispersion (Acrylic??)  -  60%
Water  -  20%
Flourescent pihgment 10  -  20 %   (do trial runs)
Filler  -  (carbonate filler of somekind)  10%
Surfactants and dispersing agents - 1-2%
Biocides  -  < 0.025%
Thickening agent   - 0.5% ??

This is very rough (thus it doesn't add to 100%!!) - -  you'd change percentages of polymer/ filler / pigment etc.. to achieve the finnish your looking for.

That will be it basically.

 

[billnotgatez]

What would be interesting is to understand how to make the Fluorescent pigment.