The role of Dimethyl Sulfoxide in Photographic Science ))

fgorga said:

Bottom line... if you are worried about exposure to a compound you should use protective gear (gloves, etc) whether or not DMSO is present.

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Fair enough! One needs to be aware that not all gloves are the same as far as protection from DMSO is concerned.

bnxvs said:

https://www.delasco.com/potassium-hydroxide-10-with-dmso/ (10% KOH in DMSO)

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Let me add MSDS for this here.

Raghu Kuvempunagar said:

Let me add MSDS for this here.

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You're welcome )) In my humble opinion, this is very useful - to collect the maximum amount of information in one topic. Thank you.

Raghu Kuvempunagar said:

Fair enough! One needs to be aware that not all gloves are the same as far as protection from DMSO is concerned.

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Thanks for posting this link to the list of suitabilities of various kinds of gloves with various chemicals. I saved the file.
Interestingly for us, nitrile gloves are rated as "excellent" for handling "photo solutions" (bottom of page 11).
Mark Overton

AgX said:

If one can store developer concentrates in glass bottles even topped with inert gas, I do not see the advantage of DMSO, more so with its shortcomings in mind.
These would also to be taken in if used just for its solvent function.

Though maybe I am slow on the uptake.

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AgX said:

But I already inquired on the benefit of DSMO facing the hassle and dangers.

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AgX said:

Strangely this discussion is restricted to the in-crowd.

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The OP brought up this thread as "discussion" on his idea. I still do not see the benefit in using DSMO. Seemingly no one used it for this so far.
And at least one proposal by the OP to my source yields the chance to blow up is set-up, the alternative at least is a hazzle.

As the OP refuses to enlighten me, maybe one of the lurkers on this thread is so kind to make me wiser.

AgX said:

I do not see the advantage of DMSO, more so with its shortcomings in mind. These would also to be taken in if used just for its solvent function.

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PAP base is known to go bad if stored as a powder and I've a kilogram of PAP that I bought from a bulk chemicals dealer in India. But unfortunately, solubility of PAP in DMSO is not as high as I would have liked it to be.

BTW if you know of an effective method of preserving PAP base, I would be interested in knowing.

AgX said:

As the OP refuses to enlighten me, maybe one of the lurkers on this thread is so kind to make me wiser.

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I don't quite understand yet, what exactly do you want to know from me?

bnxvs said:

I don't quite understand yet, what exactly do you want to know from me?

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He and probably other lurkers (including me) on this thread are wondering if you can explain why all the effort and the hazmat is worth it? So far it looks like another solvent that solves problems that are already solved, but with more risk?

Raghu Kuvempunagar said:

PAP base is known to go bad if stored as a powder and I've a kilogram of PAP that I bought from a bulk chemicals dealer in India. But unfortunately, solubility of PAP in DMSO is not as high as I would have liked it to be.

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As far as I understand DMSO is used in laboratories for its solvent characteristics, not for its protective characteristics. To the contrary, it is reported to even enhance oxidation and inert gas is thus applied too.
In general to me the most practical way is to store oxidation-sensitive materials under inert gas. But likely others may just this call a hassle. Furthermore there still is the solvent issue on some substances, where indeed DMSO at first sight seems a problemsolver.

AgX said:

To the contrary, it is reported to even enhance oxidation and inert gas is thus applied too..

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If this is true then coupled with the great affinity for moisture, it lessens DMSO's utility as a solvent.

Unfortunately, many people are now not inclined to study and analyze materials on their own. Sorry.
a) about the "oxidizing" properties of DMSO - please provide a link to the source of such a statement. I have completely different information (links are given above).
b) in this thread, I already mentioned that the value of DMSO is that it provides the ability to create very concentrated, single-solution liquid developers, without water. Especially in combination with various glycols and ethanolamines. It seemed to me that this is quite clear to anyone interested in this issue.
c) if something isn't used it doesn't mean that it cannot be used! Otherwise, our ancestors would never have come down from the trees.


p.s. In the end, if you think that DMSO is useless for you, this is your right. We are all free people, so far ...

Raghu Kuvempunagar said:

If this is true then coupled with the great affinity for moisture, it lessens DMSO's utility as a solvent.

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Water is not unpleasant in itself, but because of the oxygen and CO2 dissolved in it (always). It is the ones that cause accelerated oxidation. A small amount of moisture, likewise, includes TEA / DEA, for example. And in the same way TEA is hygroscopic. However, this does not prevent it use as solvent and preservative in photochemistry. And the ability of DMSO to dissolve and retain SO2 in significant volumes completely eliminates the problem of oxidation of developing substances.
I'm more surprised that Kodak didn't use it in the new HC-110 formula. All forums are filled with lamentations about the presence of water in the new HC-110 and suggestions that this will shorten its shelf life.
Of course, on the other hand, then everyone would be screaming about the risks of allergies and skin poisoning (as if they were about to take a bath in a concentrate).

Bnvx,
You got a strange attitude. You start a discussion on an ex-arte approach on making developing agent concentrates. Well, so far so good. I am open to new approaches. And I am curious and eager to learn. Would I otherwise have clinged to your thread?
But I did not even saw the problem. At least not to an extent that to my mind would be good enough for the risk of hassle you are planning to undergo. I even stated to may be slow on the uptake. Thus I was not arrogant. And at least one other fellow was clueless too.

And then saying to mind ones own buisiness if being of other opinion is lame. All I said was based on not seeing the cause for the trouble and being refused an explanation.

The risk of forcing a volatile disintegration during the preparation of the sulfite donor seems off the discussion now, if I understand you right by acquiring a Drechsel-bottle for inducing externally prepared SO2.

Concerning the penetration of DMSO through protective sealing (I know that DMSO on its own is rather harmless) and on its lack of yielding protection against oxidation here is a interesting article:
https://blogs.sciencemag.org/pipeline/archives/2008/05/20/the_miracle_solvent

It seems to me that we don't understand each other very well ... Of course, my very mediocre English is to blame)))
But I'm not a supporter of the approach where the issue is considered only when there is a problem. I'm more impressed by the free search for alternatives. I see potential in DMSO, and I need to figure out what can be done about it. But I also don't have ready-made answers to all questions, and as you do. I just go and do it. And I try to find these answers ... maybe sometimes, for even unasked questions)))

p.s. As for the risks ... I still think that the issue of risk when working with new photochemicals is always greatly exaggerated. This is of course justified, since it is always best to play it safe. However, I do not see any panic about the use of dichromates, cyanides, very toxic CDs, etc., although they are much more dangerous to health. Let's not inflate the elephant out of a fly, please.
Moreover, a person who is little familiar with chemistry and has no idea about safety precautions is unlikely to read this topic, and even more so to try to repeat any experiments ... simply because he is unlikely to understand what is at stake at all.
At least I hope so

p.p.s. About the article. Thank you, interesting. It's a shame it is more of a blog post, i.e. literature rather than a serious source.
I already wrote about the hygroscopicity of DMSO above. It's not a problem. At least not a big problem than using ethanolamines or glycols (and especially glycerin).
As for oxidation, oxygen is such a "dirty thing" that it gets everywhere. Neither glycols, nor DMSO, nor excess sulfite will keep your solutions forever safe. It would be ridiculous to expect this. But in contrast to medical microbiology (which, as I understand, is referred to in the article), we have slightly different volumes and different requirements for purity of solutions. I won't be too upset if a couple of hundred atoms are oxidized in my concentrate ... Look at the "one-year-old" Rodinal and you will understand everything )))
And, finally, about the fact that DMSO isn't an inert solvent. Yes, there are substances with which it reacts (with boron trichloride). It can even lead to an explosion, for example, when heated in the presence of carboxylic acid chlorides. But tell me - why would someone need this? I cannot imagine such a situation in a darkroom.
When TEA-based concentrated developers became "fashionable" no one was indignant that nitrogen mustard gas is obtained during nitriding of TEA in the presence of certain substances. Yes, and make explosive substance from ethanolamines is also not a big problem. However, many people enjoy using PС-TEA or 510-pyro, etc. So...
Sorry for my "google"-English

@bnxvs I'm all for exploration, please don't think I'm suggesting you should stop. But I think the beginning of the thread maybe didn't set out your intention that clearly. In any case, I'm all for experimentation, so if you find something good here, then thanks for advancing the science. For myself I think I'll not mess with this chemical at home since propylene glycol works well enough for me for the substances I've cared to dissolve in a water-free environment so far. I'll continue to watch the thread.

Thank you for the long reply.

bnxvs said:

It can even lead to an explosion, for example, when heated in the presence of carboxylic acid chlorides. But tell me - why would someone need this? I cannot imagine such a situation in a darkroom.

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German Wikipedia puts the spontaneous, explosive disintegration at 190°C first as danger from DMSO. Adding several groups of compounds that would significantly reduce that temperature, including acids in general. And that is what came to my mind when you had it over adding metabisulfite and heating it up a little for freeing SO2, as typically one adds an acid for that.

bnxvs said:

However, I do not see any panic about the use of dichromates, cyanides, very toxic CDs, etc

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you forgot mercury, definitely should be on your list of things not to worry about, tempest in teapot and all that.

Well, I just can't stop you from intimidating yourself into a panic coma ))) This is everyone's personal right.


OK. If there are no other opinions, I will stop publishing on this topic. No problem.

bnxvs said:

https://www.delasco.com/potassium-hydroxide-10-with-dmso/ (10% KOH in DMSO)

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@bnxvs: This concoction of 10% w/w Potassium hydroxide, 47% w/w DMSO and 43% w/w water is very interesting. I wonder if this concoction of Potassium hydroxide + DMSO in water allows one to formulate a substantially more concentrated Rodinal substitutes. Note that solubility of PAP base in water is low and Potassium hydroxide increases its solubility by converting PAP base into the more soluble phenolate salts. Using Potassium hydroxide, Gainer was able to dissolve 80g of PAP base in ~1000ml of water for his EZ Rodinal and this probably is the maximum one can do with just Potassium hydroxide. With the additional solubility offered by DMSO and the fact that it is totally miscible with water, it might be possible to dissolve more than 80g of PAP base in ~1000ml of water + DMSO using Potassium hydroxide.

Here is a possible line of attack:
1. To 250 ml water, add 60g anhydrous sodium sulfite. Add 40 g p-aminophenol base. Stir well.
2. Add 192g of Delasco 10%. Stir well till all of p-aminophenol dissolves.
3. Add 25g anhydrous sodium sulfite. Stir well.
4. Add water to make 500 ml.
This gives Gainer's EZ Rodinal with some DMSO used in place of water. Now, to get a more concentrated stock solution, one can add PAP base in small increments to the solution after step 2 till it dissolves no more. If phenolate salts are significantly more soluble in DMSO than PAP base just like they're in water, then there's a good possibility that we may be able to get a substantially more concentrated Rodinal substitute through this route. That's a big if.

Raghu Kuvempunagar said:

@bnxvs: This concoction of 10% w/w Potassium hydroxide, 47% w/w DMSO and 43% w/w water is very interesting. I wonder if this concoction of Potassium hydroxide + DMSO in water allows one to formulate a substantially more concentrated Rodinal substitutes. Note that solubility of PAP base in water is low and Potassium hydroxide increases its solubility by converting PAP base into the more soluble phenolate salts. Using Potassium hydroxide, Gainer was able to dissolve 80g of PAP base in ~1000ml of water for his EZ Rodinal and this probably is the maximum one can do with just Potassium hydroxide. With the additional solubility offered by DMSO and the fact that it is totally miscible with water, it might be possible to dissolve more than 80g of PAP base in ~1000ml of water + DMSO using Potassium hydroxide.

Here is a possible line of attack:
1. To 250 ml water, add 60g anhydrous sodium sulfite. Add 40 g p-aminophenol base. Stir well.
2. Add 192g of Delasco 10%. Stir well till all of p-aminophenol dissolves.
3. Add 25g anhydrous sodium sulfite. Stir well.
4. Add water to make 500 ml.
This gives Gainer's EZ Rodinal with some DMSO used in place of water. Now, to get a more concentrated stock solution, one can add PAP base in small increments to the solution after step 2 till it dissolves no more. If phenolate salts are significantly more soluble in DMSO than PAP base just like they're in water, then there's a good possibility that we may be able to get a substantially more concentrated Rodinal substitute through this route. That's a big if.

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Yes, this idea looks very promising. Most likely, the amount of KOH will have to be slightly increased if not just DMSO is used, but its adduct with SO2. In order to bring pH to the required indicators.

bnxvs said:

Well, I just can't stop you from intimidating yourself into a panic coma ))) This is everyone's personal right.


OK. If there are no other opinions, I will stop publishing on this topic. No problem.

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bnxvx
thankfully someone saw me in the coma on the public transit ( bus ), the driver threw it on "cruise control" used the smelling-salts to revive me. to thank him for recussitating me I bought him a bromo-seltzer and a coffee at the end of the route, we chit chatted, he told me he was also a shutterbug ... I told him about photrio, then asked what put me into the panic coma on the bus so I let him read this thread ... thankfully I found the cruise control and there were more smelling-salts..

naaah. keep going keep posting. I love reading this stuff, but im not that much of a thrill seeker to do it myself, but I love reading about other peoples' adventures. years ago an Australian lab owner asked what he should do with all this uranium he got from the darkroom at his local Catholic Church .. so now at least you know you are in the right place

eyes wide open and reading...
John

bnxvs said:

Yes, this idea looks very promising. Most likely, the amount of KOH will have to be slightly increased if not just DMSO is used, but its adduct with SO2. In order to bring pH to the required indicators.

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It might make sense to first determine the solubility of PAP base in DMSO + KOH + Water.

We know that solubility of PAP base in DMSO > solubility of PAP base in KOH + Water >> solubility of PAP base in water. The hope is that solubility of PAP base in DMSO + KOH + Water will be much higher than any of these. This is assuming that phenolates formed will be more soluble in DMSO.

1. Dissolve 40g of PAP base in 400ml of DMSO.
2. Add 38.4 ml of 50% KOH and mix well.
3. Add 40g of PAP base and stir well.
4. Add water to bring the volume to 500 ml.
After this step, PAP would have formed phenolate salt by reacting with KOH. I'm using Gainer's formula of using 19.2g KOH per 80g of PAP base.
4. Add 10g of PAP base and stir well.
5. Add 4.8 ml of 50% KOH and mix well.
6. Add water to bring the volume to 505 ml.
Repeat steps 4, 5 & 6 till no more PAP dissolves.

Suppose if we did steps 4, 5 & 6 above n > 0 times and found out that PAP doesn't dissolve any more. Then the volume of the solution after n-1 steps is 500 + (n-1)*5 and the amount of PAP based in solution is 80 + (n-1)*10.

w/v percentage of PAP base in the solution = (40 + (n-1)*10)/(500 + (n-1)*5) = (30+10n)/(495+5n).

If it turns out that n >=5 then we can make a good case for a more concentrated Rodinal substitute using DMSO. This is because when n = 5, we have w/v percentage of PAP base in the solution = 80/520 whereas for EZ Rodinal it is 40/500.

OK... With pleasure I'll continue these experiments, but after the holidays. Happy New Year everyone! And let that finally put an end to this whole crazy with Covid and global crisis. Wish you health and good ideas!

Does trisodium phosphate (TSP) dissolve in DMSO?

Dissolution of ascorbic acid in DMSO.
I was able to dissolve 10g of ascorbic acid (vitamin C) in 30ml of cold DMSO. I think that it will probably be possible to dissolve the same 10g of ascorbic acid in 20ml of DMSO, but with a slight heating of the mixture. Conclusion - ascorbic acid dissolves very well in DMSO.
Added to the prepared mixture 0.25g of phenidone, dissolved separately in 1ml of DMSO (25% solution). As a result, I got a good and twice as concentrated base (about 50ml) for the preparation of ascorbate developers according to the method of P.Gainer, described in his article "The role of antifreeze in photographic science".