Bloxygen (argon) spray

[Kino]

Been looking for someone to do this for a while. I understand you can use Butane as a liquid chemical preservative, but I'd rather not use flammable gas and investing in a rechargeable cylinder and regulator for Argon was too much.

Just ordered a few cans; anyone else try this?

Bloxygen - Inert Gas Preservation

Save your leftover paints, finishes or food from getting ruined by oxygen or moisture. Simply spray, seal and store for up to 10 years. Never have hardened paint or rubbery finishes ruin your day. Safe for food, coffee, cannabis. Tested by manufacturers. Industry best practice.

www.bloxygen.com

 

[DREW WILEY]

There are wine preservative inert gas canisters too.

 

[Kino]

These are pure Argon; the wine preservatives usually have a mixture of gasses.

Might not matter, but it's only marginally more expensive per spray can.

 

[MattKing]

Paint preservers too:

 

[bewilson]

My innner chemist just got interested.

Looking at https://www.ready.noaa.gov/documents/TutorialX/files/Chem_henry.pdf which shows how much each gas dissolves into water, here are the relative solubilities of some common gasses that aren't acidic nor basic:

Gas Solubility (molar/atm) reactive?
Oxygen 0.0001 YES (so don't use this)
Hydrogen 0.0008 YES
Nitrogen 0.0003 NO
Argon 0.001 NO
Butane 0.001 Maybe (I really don't know here because I don't know the reduction potentials of the developers, but think it's higher than 0.8v)

In using gasses to purge oxygen out of the headpace of a solution, the main consideration is how much dissolves. If you add a very soluble gas over the solution, it will dissolve, creating a vacuum in the headspace. That vacuum will pull air into the bottle, and your developer-preservation plan is foiled. So, avoiding those gasses that will react with your developer (O2 and H2), nitrogen is the next best of the common gasses. Nitrogen also has one MASSIVE advantage over all the other gasses: it's already saturated in the solution! It got there when the water came out of your aerating faucet (provided you didn't boil the water before making your developer).

In the labs I worked in we always used nitrogen to displace oxygen unless we were using a reaction where nitrogen was one of the reactants (like nitrogenase studies).

So, who sells canned nitrogen gas?

P.S. This always works best when you sparge the solution with the headspace preservative, ie. blow the gas deep into the solution. Little red straws for the win.

 

[qqphot]

Nitrogen should be fine for anything, I suppose. But for photo chemicals I've sometimes wondered if Dust-Off (difluoroethane) would be good enough. It's probably a bit more water soluble than you'd want at 0.02g/100mL but I wonder if it's reactive with anything commonly used in photochemistry. I'm unfortunately too lazy to do side by side tests to find out if it impacts development.

 

[sufnturf]

My innner chemist just got interested.

Looking at https://www.ready.noaa.gov/documents/TutorialX/files/Chem_henry.pdf which shows how much each gas dissolves into water, here are the relative solubilities of some common gasses that aren't acidic nor basic:

Gas Solubility (molar/atm) reactive?
Oxygen 0.0001 YES (so don't use this)
Hydrogen 0.0008 YES
Nitrogen 0.0003 NO
Argon 0.001 NO
Butane 0.001 Maybe (I really don't know here because I don't know the reduction potentials of the developers, but think it's higher than 0.8v)

In using gasses to purge oxygen out of the headpace of a solution, the main consideration is how much dissolves. If you add a very soluble gas over the solution, it will dissolve, creating a vacuum in the headspace. That vacuum will pull air into the bottle, and your developer-preservation plan is foiled. So, avoiding those gasses that will react with your developer (O2 and H2), nitrogen is the next best of the common gasses. Nitrogen also has one MASSIVE advantage over all the other gasses: it's already saturated in the solution! It got there when the water came out of your aerating faucet (provided you didn't boil the water before making your developer).

In the labs I worked in we always used nitrogen to displace oxygen unless we were using a reaction where nitrogen was one of the reactants (like nitrogenase studies).

So, who sells canned nitrogen gas?

P.S. This always works best when you sparge the solution with the headspace preservative, ie. blow the gas deep into the solution. Little red straws for the win.

The most commonly used "spray" (in Germany I think) to preserve photographic chemicals was Tetenals “Protectan”.
It can simply be summarised by calling it “expensive dust off” or Propane + Butane.
IMHO it should be safe as long as there’s no fire hazard around and displaces oxygen whilst being heavier than air.