ammonium hydrosulfide 2

[TTMT]

Dear All,

I am searching for a manufacturer/vendor (in Europe if possible) from where I can order ammonium hydrosulfide for inorganic black dyeing (ECSS-Q-ST-70-03C) of Aluminium, in laboratory conditions (not industrial, just some pieces of Al would be tried out).
Please help!

 

[TTMT]

I've found an article from 1997 (Anodizing and Inorganic Black Colouring of Al alloys for Space Applications). It says:". . .Immerse the work in a solution of yellow ammonium sulfide (NH4)2S 20-40g/L for 10 min."
Is this the solution of ammonium hydrosulphide? I found a supplier that sells ammounium sulphide solution (CAS:12135-76-1) 40-08wt%. It is possible to use this chemical? Are these identical?
I am confused. Please help!

 

[CoryPad]

Ammonium hydrosulphide {(NH₄)₂HS} is also known as ammonium hydrogen sulfide or ammonium bisulfide. This is NOT the same as ammonium sulfide {(NH₄)₂S}, although they are similar (think buffered solutions). You may be able to use either. I would stick with the ECSS recipe. You should be able to get the bisulfide chemical from one of these sources:

Chemos GmbH in Germany
Esseco Srl in Italy
FMC Foret, S.A. in Spain

 

[TTMT]

Thank you, CoryPad, for the tips! One more question: I've run into the same problem with nickel-acetate. I found only nickel acetate tetrahydrate in most of the catalogues, but not nickel acetate. I guess they are not the same (are they?) and I think I should stick to the ECSS.

Kind regards,

FK

 

[CoryPad]

Tetrahydrate means it is a hydrated form of nickel acetate. That should work for you.

 

[unclesyd]

Just remember to take in account the water of hydration when calculating concentrations based on concentration of Nickel in the bath, especially if the recipe calls for the anhydrous form.

 

[TTMT]

Many thanks for the answers!