[oldtanner]

First off, Im not a HS student. I wasnt really sure where to post this question?

Tanning skins, involves a first step, of pickling a skin. Pickling, is the process of combining salt, and acid, in water, and placing said skin, in this solution for a few days. Prefered Ph, is around 2. After this, the skin is thinned, then tanned and neutralised. Skins are then oiled, to impart softness, and stretch.
The Tannage is usually cationic, and the oil used to soften the skin, is anionic. This can also be vise-versa.

Ok, here is the question. If I were to mix a cationic tan, a anionic tan, and an anionic oil together(say one gallon of each of the 3), and apply heat, say 150degreesF, would this mixture remain multi-charged, or would one charge over power the other, to form a single charge?

Thank you in advance for your time!

[renge ishyo]

If I were to mix a cationic tan, a anionic tan, and an anionic oil together(say one gallon of each of the 3), and apply heat, say 150degreesF, would this mixture remain multi-charged, or would one charge over power the other, to form a single charge?

If you mix an aqueous solution at low PH (say 2) with a solution at high pH (say 10) together and apply heat the result will likely be an explosion. The mixture would not remain multi-charged, in fact, the probable result is a very rapid neutralization reaction between the cationic and anionic species to result in a species with no *no charge*. This result completely defeats the point of adding the charged species to the tanning process to begin with, so yes the species must be added separately in separate steps if they are to have any useful effect at all.

One more thing, in order to avoid an explosion, notice that one of the steps requires that you neutralize the skin (to pH=7) before switching from anionic to cationic or vice versa? This is a very important step in the process for safety, be sure you do not skip this step either as the pH must be very slowly and carefully monitored and changed to avoid an explosion. Follow all the recommendations in the published procedure carefully, and you should be fine.

[Borek]

If you mix an aqueous solution at low PH (say 2) with a solution at high pH (say 10) together and apply heat the result will likely be an explosion.

Neutralization, for sure. Bubbling and evolving heat - perhaps. Poisonous fumes - hard to exclude not knowing compositions. Explosion? Unlikely.

[billnotgatez]

We often see this safety tip

 

If you add water to concentrated sulfuric acid, it can boil and spit and you may get a nasty acid burn

Could this not happen with adding strong bases to strong acids and vice versa?

[renge ishyo]

Neutralization, for sure. Bubbling and evolving heat - perhaps. Poisonous fumes - hard to exclude not knowing compositions. Explosion? Unlikely.

All right, I'll concede that "explosion" wasn't the right word because it conjures up images of dynamite. Really really intense and fast boiling over might be the best way to explain the likely outcome?  I mean he is is mixing a gallon of acid and base and heating to 150 degrees...not sure what is the best way to describe that something like this is "bad."

Poisonous fumes are another thing that could be added. I've breathed these in a few times when sloppily adding a bit of water to ultrapure sulfuric acid...not fun stuff.

[oldtanner]

Thank you all for you responses. I really dont think I made my self clear? Forget the Ph of 2. I was giving a very general explanation, of the tanning process, with the pickle step, being the first. After this step, the skin is thinned, then neutralised, in a solution of water, salt, and sodium bi-carbonate.

After this, comes my question. I have been working on a one step tannage, that tans, and oils, all in one step. Here are the 3 ingredients.

1. an aluminum sulphate based powder, with masking agents Ph of 3
2. A phenolic based liquid, with a Ph of 3
3. a synthetic oil, with a ph of 5.5, that is made to remain stable, at all Ph ranges, with little breakdown.

The first ingredient is cationic, and the other 2 are anionic.

Now, here is my question, hopefully with a better explaniation, of my question.LOL
I have already had great success with this product, with no mixing problems, or applying heat. Would you consider this mixture multi-charged, or would one of my ingredients overpower the others, and render the whole mixture, a single charge? Thank you again for your time.

[408]

No

Aluminum sulfate is both cationic and anionic  Al3+ and (SO4)2-
phenol based liquid implies lack of significant ionic species, and is organic ie non-ionic
oil again implies non-ionic

The tanning terminology taught to you is very contradictory to the chemical reality.  Is there some sort of online tanning manual using such terms that I can look at?

[Borek]

Would you consider this mixture multi-charged, or would one of my ingredients overpower the others, and render the whole mixture, a single charge?

I must confirm what 408 wrote - this nomenclature has nothing to do with the way word 'charge' is used and understood in physics and chemistry. I am not suprised as many crafts use their own jargon.

[oldtanner]

Gentelmen, thank you very much for your time! No 408, there is no manual. Most of my information has come from "leather chemists", or so they call their selves.

After doing some reading of your forum, over the last couple of days, I am finding myself doubting the title these gentelmen have given theirself!?

Once again, thanks! I will be back, but I will be doing more reading, and learning, from TRUE masters of their chosen profession.