Strange effect of Ascorbic Acid + DEA

[Relayer]

Hello

I'm experimenting with some two bath devs with DEA+Sulfite in 2nd bath. follow is the some interesting results

*** 1
very simple VitC-DD

Bath A
Ascorbic Acid 10g
Water 1l

Bath B
DEA 30ml
Sodium Sulfite 35g
Water 1l

PolypanF 50@50. 3min+5min. underdevelopment more than 1 stops. high contrast

*** 2
bath B same. bath A modified to Ascorbic Acid 20g/l. underdevelopment half stop. still high contrast

*** 3
bath B same. add to bath A 3g/l Sodium Carbonate. as result we have in bath A mixture of 10g/l of Ascorbic Acid and 10g/l Sodium Ascorbate.
underdevelopment more than 1 stop. compare this to pure Ascorbic Acid bath A - if we replace some ascorbic acid to sodium ascorbate we have less active developer!!

*** 4
some working solution (HPMA-DD)

Bath A
Metol 2g
Pyrocatechin 5g
Ascorbic Acid 5g
Water 1l

Bath B
DEA 30ml
Sodium Sulfite 35g
Water 1l

3+3min produce very good result with nominal EI.
but when I can try to change bath B to the next:

Bath B
Trisodium phosphate dodecahydrate 15g
Sodium Sulfite 35g
Water 1l

WOW! I was fail - test film underdeveloped more that 2 stops! Its really strange, because Trisodium phosphate bath B have pH 12. compare this to DEA bath B pH 11. I guess that Ascorbic Acid with DEA produce some "superadditive" effect.

 

[Alan Johnson]

***4 Accept there is quite a probability of being wrong when a guess is made but if DEA is a silver solvent there may be redeposition of silver (physical development) in DEA.
But you have made an interesting discovery if it is verifiable.
It would be interesting to compare the DEA bath B to Potassium Carbonate as the latter is widely used. It would reveal if DEA really has unknown useful properties.
It is a component of Ilfotec LC29, see msds.

 

[eclarke]

Why DEA instead of TEA?..Evan Clarke

 

[Photo Engineer]

Remember several things here:

1. DEA is a stronger base and stronger silver halide solvent than TEA.
2. Additions or changes change pH. Without knowing what direction it went, we know nothing for sure.

PE

 

[Relayer]

***4 Accept there is quite a probability of being wrong when a guess is made but if DEA is a silver solvent there may be redeposition of silver (physical development) in DEA.
But you have made an interesting discovery if it is verifiable.
It would be interesting to compare the DEA bath B to Potassium Carbonate as the latter is widely used. It would reveal if DEA really has unknown useful properties.
It is a component of Ilfotec LC29, see msds.

last month I'm experimenting with DEA/MEA as alkali. typically concentration about 10-20ml/l. I haven't anything related to "silver solvent" property of DEA. maybe because I was use DEA in low concentration around 1-2%

other interesting thing about *4*. if I replace Ascorbic Acid in bath A to Sodium Ascorbate in same amount - bath B with Trisodium phosphate working very well and give me nominal EI
i.e. free Ascorbic Acid in bath A working ok with DEA 2nd bath. and not working with Trisodium phosphate 2nd bath (I guess that it also can't be working with other alkali such Sodium Carbonate, Borax etc)
bath A with Sodium Ascorbate have less activity with DEA 2nd bath, but working ok with usually used alkali like Trisodium phosphate, Sodium Carbonate, Borax etc

 

[Relayer]

1. DEA is a stronger base and stronger silver halide solvent than TEA.

ohh. i was read many abstract posts that DEA/MEA is the strong silver halide solvent. do you know that Sodium Sulfite also? I can't find any info about concentration of DEA/MEA when this property of DEA/MEA is really visible.

HPMA-DD (case *4* with DEA 2nd bath) in action. no postprocessing

my other experimental 2bath developer. 1st bath with Amidol+Ascorbic Acid, 2nd bath DEA+Sodium Sulfite

2. Additions or changes change pH. Without knowing what direction it went, we know nothing for sure.

I was specify pH for 2nd bath: 11 with DEA and 12 with Trisodium phosphate. pH of 1st bath isn't so important

PS HC110 concentrate contains both DEA and MEA. can you comment this?

 

[Photo Engineer]

Well, 2 bath developers are tricky because they rely on imbibition of part A which depends on swell and original emulsion thickness, hardness and other characteristics such as pH. So, the activity of 2 bath developers is very hard to judge or predict when formulating one. It will also tend to differ with different films.

Silver halide solvent capability is in the order MEA > DEA > TEA with TEA being weakest. Sodium Sulfite is somewhere to the left of the middle IIRC. The HC110 uses Sulfur Dioxide to make a MEA/DEA adduct in situ to preserve the developer and balance the solvent effects using the amines. Sulfite is an actor here as well, but to what extent IDK.

PE

 

[Relayer]

The HC110 uses Sulfur Dioxide to make a MEA/DEA adduct in situ to preserve the developer and balance the solvent effects using the amines.

I'm not agree with you. Diethanolamine sulfur dioxide complex is only complex solution of DEA with SO2. because SO2 very easy dissolved in DEA. really SO2 don't need to preserve developer, because DEA as organic solvent keep all components very good. but Sodium Sulfite can't be dissolved in glycol/TEA/DEA/MEA. so interesting solution is use DEA+SO2 instead Sodium Carbonate+Sodium Sulfite.
Why we need Sodium Sulfite or SO2? because HC110 based on Hydroquinone and Sodium Sulfite need for partial recovery/coupling Hydroquinone while it work

 

[Photo Engineer]

DEA and TEA, being organic bases and SO2 being an inorganic acid, they react rather strongly to form the salts of the respective bases and acids. In the absence of water, one calls them adducts because they are held together by electron bonding. In water, they disassociate, but do not form Sodium Sulfite as not enough sodium is present so they are present as acid base pairs in the water.

Sulfite does not act strongly as a solvent in this case, but it can to some extent, and so DEA is the primary silver halide solvent. Sulfite is the preservative which acts by scavenging oxidized developing agents. MEA is probably too strong, but IDK, as I have never run the test.

PE

 

[Photo Engineer]

Looking at the MSDS of HC110, I find that the SO2 complex or adduct is as high as 55% or 500 g/l in the concentrate and as high as 5% or 50 g/l in the working solution varying from 10 g/l to 50 g/l. This puts it into the range of Sodium Sulfite as used in D-76, and depending on activity and concentration will cause different effects from dilution A to dilution H.

PE

 

[Relayer]

DEA and TEA, being organic bases and SO2 being an inorganic acid, they react rather strongly to form the salts of the respective bases and acids.

in industry DEA used for cleaning because CO2, SO2 very easily absorb in DEA solution. by example see here
SO2 is gas. it can't react with DEA. no salt produced. it just dissolved in DEA

from here

 

[Relayer]

Looking at the MSDS of HC110

MSDS isn't good starting point for HC110 because omit some components. see US patent 3.552.969

 

[Removed Account2]

DEA and TEA, being organic bases and SO2 being an inorganic acid, they react rather strongly to form the salts of the respective bases and acids. In the absence of water, one calls them adducts because they are held together by electron bonding. In water, they disassociate, but do not form Sodium Sulfite as not enough sodium is present so they are present as acid base pairs in the water.
PE

You been called on this already....
electron bonding isnt that what is generally known as the force that keeps all molecules together?
Generally when trying to explain intricacies of chemistry to a non-chemistry public, its a good idea to try to present the matter in a simple manner, not clouding the issue by offering varying names and concepts of the same thing......

 

[Photo Engineer]

Actually, I originally used the word "adduct" to describe the result of bubbling SO2 gas through DEA or TEA. This was in post #7. Relayer used the word "complex" but it is certainly not a classic complex. So, we have at least 3 descriptions here of what it is.

The literature describes it as a complex but I am more used to metal-organic complexes in the traditional sense. So, IMHO take your pick. Since the original poster appears to have some chemistry background and has strong opinions, my offers to assist seem to be of little use.

Actually, HC-110 also uses the "adduct" or "complex" or "salt" of HBr with DEA as well so as to supply a halide restrainer. Some MSDS mention that and some do not. However, those that do not, mention that KBr is used, but KBr is not soluble in the syrup.

PE

 

[Removed Account2]

Where does your HBr come from?? HC 110 never interested me much, but I'm willing to listen and learn!

 

[Photo Engineer]

HBr is bubbled through a container of DEA to make the "whatever" of HBr.DEA at the right molar proportions. It is in-effect, the same method used to make the SO2.DEA "whatever". You need a trap in the setup to prevent sucking the DEA back into the gas supply line and tank, as the reaction can be quite vigorous. You need to cool the DEA to prevent overheating.

PE

 

[Removed Account2]

This not for my WIFES kitchen! I'm outta here, unless I pick up bad habits from you scoundrels, I don't want to go to no lawyers office and be handed a note telling me to sell off my cameras and handguns!

 

[Photo Engineer]

Well, I must admit that recent MSDS sheets show KBr, but earlier ones even just a year or so ago showed HBr.DEA.

Maybe the new chemical manufacturer for Kodak has changed the formula.

PE

 

[Removed Account2]

Or maybe one of them finally got married.....