Jump to content
APC Forum

Alternative blues


Recommended Posts

Posted

I've just read a small text on pyro and seen Caesium (cesium) suggested as a Blue colourant. From it's obvious spectrum I can see some possibility, but Cs formate is used as an infra red emiter for military flares and decoys.

 

Has anyone any wisdom to share. Has anyone any info on the solubility of Cs salts I'm guessing that CsCl should be soluble in water and possibly in alcohol too.

Posted
It's has a good solubility, 162 g/100 ml (1 °C) according to Wikipedia.The infrared part of the spectrum isn't really interesting though, you can't see it anyways. I think coppersalts and ammonium perchlorate are a way cheaper way to achieve a nice blue though. My sources tell me caesium chloride is quite expensive.
Posted
From the photographs I've seen on the internet, it does not look nearly as good a blue as copper. Having said that, I'd still love to get some to try it for myself...
  • 3 weeks later...
Posted
At some 1 dollar/gram for the CsCl (the cheapest I ever saw) I doubt you'd want even to think about it.
Posted
I'm looking at colourants for type approved NC based prox flame effects and Cs in the vapour has fewer problemd than copper.
  • 4 weeks later...
Posted
From the photographs I've seen on the internet, it does not look nearly as good a blue as copper. Having said that, I'd still love to get some to try it for myself...

Probably because of the infra-red, which most cameras inevitably capture as white.

Posted
I'm looking at colourants for type approved NC based prox flame effects and Cs in the vapour has fewer problemd than copper.

 

What about indium? It looks very pretty.

Posted

Many people have tried both Caesium and Indium compounds in their search for alternatives to copper for producing blue flames. But I have not heard of a single successful experiment since the blue colours from those emitters seem to be too weak and easily disturbed to be practically useful in ordinary pyrotechnic compositions.

 

Maybe the problem is similar to the difficulties of using lithium compounds for producing red pyrotechnic flames? In the case of lithium it has been reported that the composition must be fuel rich and rely on hydrogen rich fuels. Furthermore no halogens are allowed and if they can not be avoided, aluminium should be used to scavenge the halogen. (See “Evaluation of Lithium Compounds as Color Agents for Pyrotechnic Flames” by Ernst-Christian Koch, Journal of Pyrotechnics issue 13, 2001.)

 

So, if the purpose is to get a blue flame out of NC-based effects I guess there could be a chance that Caesium or Indium would work if the oxygen balance is only slightly adjusted with a suitable oxidizer to avoid the natural yellow colour of the NC flame.

Posted
Crazy Swede, could you "arrange me" with the cited article? I'd like to read it.
Posted (edited)
Crazy Swede, could you "arrange me" with the cited article? I'd like to read it.

I'm afraid I can't do that since I'm a friend of the people running the journal. But, it's only $5 to download from here.

 

Another great source of information regarding coloured flame chemistry is the article "the Chemistry of Colored Flame" that you can find free to read from here.

Edited by Crazy Swede
Posted
Thank you, that would do it :)
×
×
  • Create New...