Sciencemadness Discussion Board

Black phosphorus storage.

CaCl2 - 13-3-2017 at 19:20

I recently bought an ampoule containing a small amount of black phosphorus.

It, however is too large to fit into its place in my element collection, So I will have to break it.

Since black phosphorus is literally more expensive than gold, and apparently at least somewhat reactive with air, I ask if someone here has information about how it should be stored.

The information available seems a bit contradictory, some suggests that it can be stored simply in closed bottles, some says it is reacts quickly with air. All supliers seem to deliver it in sealed ampoules.

Is a tightly closed bottle enough? Can it be stored under oil, or does it dissolve?

j_sum1 - 13-3-2017 at 19:44

I think the best solution is to make all the other samples in your element collection bigger to match.
:D

CaCl2 - 13-3-2017 at 19:54

Quote: Originally posted by j_sum1  
I think the best solution is to make all the other samples in your element collection bigger to match.
:D


...Actually the sizes of the other samples aren't the problem, the size of the 3D-printed frame to hold them is. Each element only has aprox. 2x2x2 cm space to itself, and phosphorus has many allotropes that I try to fit. (Carbon is even more challenging...)

PirateDocBrown - 13-3-2017 at 23:50

Black P is not terribly reactive with air. It is, in fact, the least reactive of all P allotropes. It is flammable, but only similar to carbon black. If moist, it will react slowly with O2, so you should keep it dry.

Go ahead and remove it from its ampoule, and re-ampoule it in a smaller ampoule.

[Edited on 3/14/17 by PirateDocBrown]

CaCl2 - 14-3-2017 at 00:14

Quote: Originally posted by PirateDocBrown  


Go ahead and remove it from its ampoule, and re-ampoule it in a smaller ampoule.

[Edited on 3/14/17 by PirateDocBrown]

I don't really have the equipment/experience for re-ampouling things yet.
And tiny ampoules of relatively heat sensitive/flammable materials probably aren't the best things to start ampouling with.

Since it has graphite-like structure, it probably wouldn't dissolve in mineral oil, right?

[Edited on 14-3-2017 by CaCl2]

[Edited on 14-3-2017 by CaCl2]

[Edited on 14-3-2017 by CaCl2]

PirateDocBrown - 14-3-2017 at 10:59

All you need is a glass tube and a blowtorch. I use small pyrex test tubes, but Pasteur pipettes are also commonly used, for smaller ones.

Just close off one end, then stretch the other into a thin walled neck. With a pipette, the stretching is done for you, just cut it off wide enough to get your sample in and out. With a test tube, the closing off is already done, I just flatten out the round bottom, so it'll stand upright, but that's just me.

Let them cool before putting the sample in.

Once the sample is in, hold it so the sample is in the cool bottom of the ampoule, and the heat is applied to the top, to seal it. Glass doesn't transmit heat very well. I just use ordinary long nose pliers to smoosh the soft glass, if twisting doesn't work.

I'd recommend you practice a bit on empty tubes first. Maybe put a couple drops of water in as you practice, to make sure you know it can be done without boiling the water.

If I can ampoule bromine without evaporating it, surely you can do black phosphorus.

[Edited on 3/14/17 by PirateDocBrown]

[Edited on 3/15/17 by PirateDocBrown]

MrHomeScientist - 14-3-2017 at 11:22

Quote: Originally posted by PirateDocBrown  
If I can ampoule bromine without evaporating it, surely you can do black phosphorus.

I must say that ampouling bromine was one of the more terrifying experiences in my chemistry career. Just the thought of accidentally knocking it over after sealing, causing the bromine to boil and explode the ampoule all over me, made for a very stressful 10 minutes.

PirateDocBrown - 14-3-2017 at 18:10

Quote: Originally posted by MrHomeScientist  
Quote: Originally posted by PirateDocBrown  
If I can ampoule bromine without evaporating it, surely you can do black phosphorus.

I must say that ampouling bromine was one of the more terrifying experiences in my chemistry career. Just the thought of accidentally knocking it over after sealing, causing the bromine to boil and explode the ampoule all over me, made for a very stressful 10 minutes.


Shoot, the ampouling was less stressful than the washing with sulfuric acid, for me.

I'd rather work with bromine than with HF, any day. At least you know it when bromine is killing you.