Cobalt Blue Synthesis

Matherials:
-Cobalt Salt
-Aluminum Salt
*Salts can also be made with elemental form and a suitable acid
Key Hazards: Cobalt salts are a suspected carcinogen, strong acids are toxic and corrosive, and extreme heat can cause serious burns.
Methods: "The manufacture of mineral and lake pigments, containing directions for the manufacture of all artificial artists' and painters' colours, enamel colours, soot and metallic pigments" 1901
Reupload from my Tik-tok
#science #chemistry #color #cobalt #sonic #blue

[@nomcopterlabs]

Another great video - you've definitely hit your stride and style with the voiceover and it's working well. Super impressed with how many you can churn out!

[@integral_chemistry]

Thank you! I definitely have to slow the pace down soon as I'm getting ready to move (and that means I'll also be taking a break for a month or so), but I did really want to develop a unique style/presentation before all that and I'm very happy to hear you like it! I'm also always open to constructive criticism, the only reason I make any changes is because people tend to torment me in the comments when they don't like something. It's unpleasant in the moment but definitely has resulted in some significant improvement. On that note I have a question if you could oblige me: What do you think about the mobile-centric aspect ratio I use? I figure most chem videos online already use the typical 16:9, so I felt like the 9:16 I use is part of my niche, but I'm not sure whether its annoying to viewers.

[@experimental_chemistry]

@@integral_chemistry 9 : 16 looks a bit like second-handed from T*ktok. I guess it would be better to reserve that format for Shorts.

[@daruleos]

you should at gum arabic to test how these colors would look as watercolors!!

[@spoon_bomb]

Woooooo ! Color synthesis tiiiiiime !

[@experimental_chemistry]

Needless to mention that this is another nail in the coffin of the painter (carcinogenic)... 😉 I would recommend alum as a source for aluminum ions instead of aluminum chloride, because alum very easy and cheap to obtain - unless you are about to recover copper from its acidic and chloride containing solution anyways, re-using the resulting aluminum chloride as a waste product from that procedure. Our Aluminium foil here doesn't contain many impurities, mostly a little black carbon, which is very easy to filter off. Cobalt blue is also called Thenard's blue, it's formation is a classic qualitative detection method for the presence of aluminum ions in a test substance, which can be carried out very easily on a manganenestone gutter using just one drop of cobalt salt solution which minimizes any risk of being harmed by such a small amount of that carcinogen near to zero. Now only the half-brother of this pigment is still missing: Rinman's green. 😎

[@integral_chemistry]

I'm actually working on Rinman's green as we speak! Luckily zinc gave me a much easier time than the aluminum, and right now I'm just trying to figure out ratios. From the literature I've read it seems a 1:9 ratio of cobalt carbonate and zinc hydroxide is perfect, and I think I'm going to kiln fire this time as I'm sick of cracking by big test tubes lol.

[@experimental_chemistry]

@@integral_chemistry To be honest I am not sure about the correct ratio because it doesn't matter for the analytical purposes I am familiar with. But I would recomment using a crucible for such syntheses instead of test tube which is not made for that: they just melt, crack or at least make residual moisture reflux...

[@chemistryreacts]

The stoichiometries you have used are way off CoAl2O4? I think you have just formed some CoAl2O4 on the surface of Al2O3 due to the reactivity of the precursors but not much more. Very pretty colours though!!!

[@integral_chemistry]

Oh yeah you're 100% right. Cobalt pigments are really funky and if you try to use stoichiometric quantities you end up with a pigment so dark it's nearly black and unusable. I followed a really old recipe from the 1800s that is somewhat tough to decipher, but I assume a good deal of this is aluminum oxide.. also the reaction isn't able to be balanced without some source of external oxygen which I haven't been able to figure out. I'd think a better source of cobalt would be the oxide or hydroxide but the recipe swears to the chloride..

[@sohelpervas4821]

sir can I add some water in the mixture or cobalt chloride and aluminium hidro oxide

[@EdwardTriesToScience]

for pure aluminum salts using aluminum metal i recommend dissolving the aluminum in sodium hydroxide which will not dissolve other metals, then precipitating the aluminum out as alumina with HCl (ph neutral), only issue then is that aluminum hydroxide is a horrible gel to deal with and you have to wash it with a bunch of water to remove the salt, supposedly freezing it or boiling the gel will make it behave but idk

[@experimental_chemistry]

I know aluminum hydroxide as a substance that can be filtered quite well. The real problem is adding the right amount of acid or base: too little hydroxide reduces the yield, too much hydroxide dissolves into aluminate. It is therefore doubly important to observe the stoichiometries and avoid excesses. When heated, aluminum hydroxide gives off water and becomes aluminum oxide - a good catalyst for making ethene and a great source of salts that do not form with aluminum itself. Unfortunately, producing the oxide yourself is hardly worthwhile in terms of effort and costs: aluminum oxide is a substance that is quite easy and cheap to obtain.

[@integral_chemistry]

Yeah the route I used was awful and I do not recommend. I ended up precipitating out over a gram of iron from that mess.. In the future I will probably just use reagent-grade aluminum or as he said just buy the cheap aluminum oxide lol

[@AlexYorim]

Are you gonna synthesize Ultramarine blue next?

[@PendelSteven]

Cobalt blue is the blue in the Dutch flag from The Kingdom of the Netherlands

[@slqjeueuieqpiejdjsjs]

looks very like tetraamino copper nitrate

[@experimental_chemistry]

Only insoluble substances can be used as pigments for painting, so TACN never will.

[@integral_chemistry]

I've been meaning to do a video on that stuff for ages, I simply love copper colors.

[@integral_chemistry]

True^^ however certain old copper-based pigments like verdigris and paris green have some limited solubility, which makes me confused why they were ever used as pigments..

[@experimental_chemistry]

Yeah, copper is beautiful. Phthalocyanine Blue is an example for a perfect copper based pigment. Concerning to Paris Green I am more confused about its use because of its extremely toxicitiy...

[@setoman1]

Can I drink it?

[@experimental_chemistry]

No, it's a solid...🙄 With liquids it's not the question if you can drink them, but only how often. In a chemistry lab there are many substances you will only ingest once... ☠️ Btw: cobalt compounds are slightly toxic and above all carcinogenic.