Sciencemadness Discussion Board - Why doesn't anyone use glove boxes for things like fluorine?

Why doesn't anyone use glove boxes for things like fluorine?

Draeger - 21-7-2020 at 14:47

I wonder why we don't build glove boxes out of fully fluorinated polymers (some of which are apparently transparent) and thus have a safe, inert environment? I guess it's about it not being fully airtight? But what if it would be in an ideal world, where it can only be fully sealed.

Would there be any other problems? I guess I am missing something?

Note that I am asking out of curiosity. I don't intend to do any of this. Even if this would work, there's always something that could go wrong, and one mistake could mean death or at the very least a terrible injury in the presence of F2. So, not anything I am planning. I just want to know the answer to the question I asked.

Swinfi2 - 22-7-2020 at 02:26

I've used glove boxes and the main issue I see with using one in a diy setting is the gloves, their usually fixed into the front window and I don't see an easy way of making them robust and air tight. Outside of that it's impossible to put your hands in without some way to equalise pressure and scrub the displaced gas, and in reverse prevent contamination or escape through the inlet.

Hard to make, hard to use, limited uses without needing air free or particularly toxic compounds that a shlenk or fume hood can't do better.

JJay - 22-7-2020 at 16:54

I'm told that glove boxes are used for phosgene in graduate research labs. It's slightly more toxic than fluorine but easier to handle.

Draeger - 23-7-2020 at 16:28

Quote: Originally posted by JJay

I'm told that glove boxes are used for phosgene in graduate research labs. It's slightly more toxic than fluorine but easier to handle.

That's a scary thing to work with. But I guess it's also going to be the only time in their life they can ever wield the beast that is phosgene. I don't think I'd be jealous though, phosgene isn't that useful. I'm jealous of the people who work in fluorine labs and can handle that. It's an extremely interesting element, but that's because of the same reason it is so toxic. They can at least appreciate it in some form. At least one can obtain small samples of xenon compounds very rarely from some chemical suppliers.

phlogiston - 23-7-2020 at 16:57

Draeger, are you talking about amateur or professional labs?

Watching some videos of professional labs working with fluorine, I was quite surprised to see that they don't seem to be using even a fume hood of any kind, e.g.: https://www.youtube.com/watch?v=vtWp45Eewtw

Maybe they rely on virtually all of the fluorine reacting away immediately, in combination with a well ventilated lab?

[Edited on 24-7-2020 by phlogiston]

Draeger - 23-7-2020 at 17:17

Quote: Originally posted by phlogiston

Draeger, are you talking about amateur or professional labs?

Watching some videos of professional labs working with fluorine, I was quite surprised to see that they don't seem to be using even a fume hood of any kind, e.g.:https://www.youtube.com/watch?v=vtWp45Eewtw

Maybe they rely on virtually all of the fluorine reacting away immediately, in combination with a well ventilated lab?

[Edited on 24-7-2020 by phlogiston]

I'm talking about professional labs. If anyone in an amateur lab would've managed to work with fluorine in an amateur lab without death we'd have probably heard of it, if I'm not mistaken.

Yeah, I've seen it too. They must really be confident that all fluorine is gone, since from what I have read it would be an art form to put an amount of fluorine in the air that would be safe to breath.

I'm wondering though, what is actually the main danger? Is it the systemic toxicity of HF or the corrosiveness of both the HF and the fluorine, or some other effect I don't know of?

[Edited on 24-7-2020 by Draeger]

[Edited on 24-7-2020 by Draeger]

Draeger - 24-7-2020 at 06:12

I wonder: How can they even guarantee the safety of the workers when they work with these highly reactive and/or toxic chemicals? How can they be sure that nothing can go wrong, and why can't one be so sure in a hobby lab? What is different?

[Edited on 24-7-2020 by Draeger]

macckone - 24-7-2020 at 06:52

Pure fluorine is going to react with almost everything it touches.
It will react with carbon dioxide at slightly above room temperature to form carbonyl fluoride, the fluorine analog of phosgene.
On the plus side if it contacts your skin it immediately turns in into a fluoropolymer.
The only substance that is really inert is nickel, it forms a passivation layer of nickel flouride.
Fluorine can penetrate a lot of fluoropolymers while not reacting with them.

Hydrofluoric acid is a systemic poison, it is easily absorbed.
The good news is liquid solutions in a lab are usually low concentrations so none escapes as gas.

Ammonium bifluoride is often used in labs as it provides the reactivity of hydrofluoric acid in a safer form.
It obviously isn't used for everything but for a home chemist it is much safer.

Sodium bifluoride is also used, it reacts with water to form hydrofluoric acid in situ for reactions.

For a lot of reactions, ammonium or sodium bifluoride is sufficient.
And does not produce fumes.

pure fluorine is seldom used, even in an industrial setting.

Dr.Bob - 5-8-2020 at 17:51

Most fluorine chemistry I have seen in done in metal manifolds (monel or Nickel alloys). It can be regulated handled with valves and pressure and temperature controlled. Leak testing is done with a safe gas at high pressures before ever allowing fluorine near it.

For hydrogen fluoride, it can be used as a solution in water, or more commonly via a cyinder of the anhydrous liquified HF gas. It used to be commonly used to cleave peptides from resins back in the Boc peptide chemistry era, but few people do that now. That was done in a Teflon manifold, where a reservoir was cooled with LN2, HF was condensed into it, then the gas was transferred to a reactor vessel by warming the reservoir and cooling the reactor, then sealing it so the HF would thaw and the resin (or other material to react with HF resided) would be stirred in the pressurized HF. After an hour or so, the HF was then distilled into another cooled vessel (all vessels were made from machined Teflon), and then that was then slowly vented into a base trap as it melted. It was done in a special hood with two layers of gloves that went up to your shoulder, a face mask, an apron type lab coat, and more. Once done, the reaction vessel had to be carefully put under vacuum to remove all HF traces and then sealed and further manipulated

We had calcium gluconerate solution handy as an antidote to HF poisoning/burns. HF absorbs through the skin easily in any form, and then binds to the calcium in your blood and tissue to instantly form CaF2, which both fossilizes you, and also removes Ca ions from nerve cells, which causes very bad things to happen, as they don't work without it. I don't miss working with HF, it is not fun or easy. But needed for many things.

Much of the gasoline in the US is made by isomerizing hexanes, octanes and other straight chain hydrocarbons into isooctane and other highly substituted molecules with higher octane ratings. There are some newer ways to do it, but HF is still used to do many super acid processes.

So while a Teflon glovebag might work, the cost and awkwardness of using a glovebag/box is enough to make that the last resort for handling dangerous materials. Much simpler to contain the reagent to a sealed system and manipulate it within.

Frankenshtein - 9-9-2020 at 17:13

I'm still considering making a hybrid glovebox with ducting and a 12v air matress inflator pump to air it out after use and in the event of dense clouds. It would also make an easier/cheaper fume hood with less air flow, having a valve you could open/close, sacrificing the ease of use/handling of a fume hood sash opening. I've seen in industry they have a fan and smoke filter inside. I was never aware of pressure equalizing being an issue until reading this thread. It's harder to move things in and out, you'd need a separate chamber on the side with a door and some way to safely evacuate fumes from it if you wanted to take out or put items inside during some dangerous processing. I've also seen some called "glove bags", where theyre using a large clear plastic bag (not your ordinary). I considered using clear vinyl sheeting held up by a stand to make mine easy to roll up and store in the same container as my chemicals.

clearly_not_atara - 9-9-2020 at 19:49

Gloveboxes aren't so good at fire and explosions, but fluorine can produce both under the right circumstances.

symboom - 9-9-2020 at 21:56

The only way I could think is Fluorine being use as it's formed by electrofluorination process

BromicAcid - 10-9-2020 at 16:15

There is a fluorine thread, in it I share the schematics for a fluorine cell from Inorg Synn. The author of the paper wanted to make sure it was easy enough to construct and the parts list was universal enough that a person could spend $70 at the local hardware store and cobble it together. If I'd had access to the HF to fuel the thing I'd have made the double salt cell and run it in my own back yard. It's a thing of beauty and wonder, and of course danger.

Of course current glove boxes are pressure equalizing automatically but the older style had a foot switch to fill and deflate the box. Such a thing would be much easier to accomplish at the home level. Of course the critical thing is that most glove boxes I have used are designed for the safety of the chemical (to prevent its exposure to air) rather than your own so they are not intended for toxic materials. Granted they cover a whole spectrum of abilities and there are of course glove boxes meant for toxic materials but my own experience on that front is limited.

Speaking of phosgene though, a photograph of me running my first phosgenations (in a professional setting of course) is attached to this photo. Take care and be safe.

clearly_not_atara - 10-9-2020 at 16:44

Hypofluorous acid in acetonitrile, prepared in situ from gaseous F2, is a surprisingly versatile reagent:

https://scholar.google.com/scholar?hl=en&as_sdt=0%2C40&a...

Among the transformations: amine -> nitro, ene acid -> epoxy acid (0 C, isolable), amino acid -> nitro acid, N-heterocycle -> N-oxide...

[Edited on 11-9-2020 by clearly_not_atara]

draculic acid69 - 8-10-2020 at 06:41

Quote: Originally posted by clearly_not_atara

Hypofluorous acid in acetonitrile, prepared in situ from gaseous F2, is a surprisingly versatile reagent:

https://scholar.google.com/scholar?hl=en&as_sdt=0%2C40&a...

Among the transformations: amine -> nitro, ene acid -> epoxy acid (0 C, isolable), amino acid -> nitro acid, N-heterocycle -> N-oxide...

[Edited on 11-9-2020 by clearly_not_atara]

So nitroethane/propane can be made from ethyl/propylamines
That's a big one for those who want nitro but can't get or deal with
The 7%yeilds of other synthesis.
The next question is: is it safe to work with in an amatuer setting or is it
as dangerous as flourine

Fyndium - 11-10-2020 at 03:13

I wouldn't want to be in their pants.