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MrHomeScientist
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The thorium isn't even cool yet and already you're moving on to other things! I really admire your enthusiasm.
The bismuth method sounds extremely simple and easily doable, but I haven't read the citations so it may be much more involved. Molten bismuth is
easily achievable by anybody.
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Dan Vizine
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I needed a tube furnace project. I built a 2 zone unit and I've never even used it. It was either this or vapor phase deposition of metal crystals.
Black P will be a challenge and much more profitable.
The pressure based syntheses can give bulk transformation of large(r) amounts, 80 g or more. The Au/Sn/SnI4 and Sn/SnI4 methods can give crystals up
to 1 cm, while those formed in Bi tend to be rather small in comparison. The Hg product is not worth commenting on, as it is clearly a horrible
travesty.
PS. For what it's worth, getting silver colored Ba into an ampoule is much harder to do than making thorium or black P.
I still haven't come close to cracking that nut here. Ironically, I'm helping a professor in Fla. to custom design his glovebox to do just that. Some
of the mods are truly one-of-a-kind. Each minute source of a reactive contaminate has been identified and a system put in place to address it. Now
we'll see if a slight nitrogen level, if oxygen and water are excluded, does anything to a shiny Ba surface.
[Edited on 17-8-2016 by Dan Vizine]
"All Your Children Are Poor Unfortunate Victims of Lies You Believe, a Plague Upon Your Ignorance that Keeps the Youth from the Truth They
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Dan Vizine
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Quote: Originally posted by Oscilllator | Sealing the tube in a vacuum sounds extremely difficult. Have you considered doing something like flushing the inside of the tube with (for example)
highly pure CO2, and placing a small amount of Lithium oxide in the tube to absorb this CO2, leaving behind a vacuum? |
Sealing a borosilicate glass tube while under vacuum is not difficult. It proceeds as you might imagine. You heat on side of the tube until it starts
to deflect inward, turn 180 degrees & repeat, turn 90 degrees & repeat, turn 180 degrees and repeat. With luck, the central channel has closed
already and you just heat more strongly and pull. Use the flame to fuse the channel to a rounded bump. But as I know from about 2 hours worth of
experience 20 years ago, and from everyone who has ever done it, that quartz does not act like borosilicate glass at all when you try glassblowing.
I'll need to sharpen my skills with quartz.
The chemistry of this is still very poorly understood. Even screwing up the heating cycle can have very deleterious effects. Changing more variables,
like adding lithium carbonate, is to be avoided. Ingenious idea for some projects though!
[Edited on 17-8-2016 by Dan Vizine]
"All Your Children Are Poor Unfortunate Victims of Lies You Believe, a Plague Upon Your Ignorance that Keeps the Youth from the Truth They
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Dan Vizine
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Quote: Originally posted by j_sum1 | What a great bit of research. Thanks.
Synthesising thorium aint enough for you Dan?
All of this looks well out of my league. Which of the methods do you think you will go for? |
Method 6 is the hands-down winner. Interesting enough, a group using one of our gloveboxes is doing electrical work on exfoliated single layers. It is
thanks to one of these researchers that I became aware of the Au-less route. She is, in fact, quoted pretty much verbatim in the warnings given about
ampoule integrity and the need for isolation. Interacting with these and other young university researchers is the best part of my job.
"All Your Children Are Poor Unfortunate Victims of Lies You Believe, a Plague Upon Your Ignorance that Keeps the Youth from the Truth They
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careysub
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Here is a previous thread on this, where I uploaded the original paper about method 6 (Lange, 2007):
http://www.sciencemadness.org/talk/viewthread.php?tid=12196
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clearly_not_atara
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Quote: | Black phosphorus single crystals were prepared from a solution of white phosphorus in liquid bismuth.The bismuth is dissolved away with (1:1) HNO3.
Brown A, Rundqvist S (1965) Refinement of the crystal structure of black phosphorus. Acta Crystallogr 19(4):684–685. See also: Synthesis and some
properties of black phosphorus single crystals Y. Maruyama, S. Suzuki K. Kobayashi, S. Tanuma |
What if a bismuth eutectic alloy were used? The eutectic alloy of bismuth and tin melts at 140 C. Tin forms a phosphide but at low enough temperatures
it might be possible to dissolve phosphorus without reaction. Field's metal in particular might dissolve phosphorus, although it may slowly form
indium phosphide. The eutectic of bismuth, lead and tin melts below 100 C.
So I think this route is underrated: it does not first of all carry the possibility of explosion, and secondly, it doesn't seem impossible to recycle
the bismuth (or alloy) for multiple uses, since it should be converted to the nitrate, which can then be reduced. Even pure bismuth melts as low as
270 C. It forms an auride (ick) and the melting temperature is not appreciably depressed by silver, but eutectics exist with lead and tin which are
interesting.
EDIT:
http://iopscience.iop.org/article/10.1143/JJAP.28.1019/meta
[Edited on 17-8-2016 by clearly_not_atara]
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Dan Vizine
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Oops careysub, sorry. Maybe it should be merged?
clearly-not-atara, the goal is not just to make black P, it's to make the largest crystals possible.
"All Your Children Are Poor Unfortunate Victims of Lies You Believe, a Plague Upon Your Ignorance that Keeps the Youth from the Truth They
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j_sum1
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Quoting from the related thread...
Quote: Originally posted by Fleaker | Yep, better get it while you can! It's not that easy to make and rather bothersome to recover the expensive reagent used in its synthesis (believe me,
I've done it ).
I'm going to have another crack at it sometime soon though. |
Ok. Now I'm curious. Fleaker, if you are around, what method did you employ?
I continued reading the thread but could not identify which method you said you were successful in.
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Dan Vizine
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He used method 5. That's why method 6 is a no-brainer, no gold needed, same results or better.
[Edited on 18-8-2016 by Dan Vizine]
"All Your Children Are Poor Unfortunate Victims of Lies You Believe, a Plague Upon Your Ignorance that Keeps the Youth from the Truth They
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MrHomeScientist
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Let's say I just want to make a small amount of black P for display in my element collection. How does the bismuth method (#3) work? Do you have more
details? It sounds exceedingly simple, and could make a nice video that others could try. I have lots of Bi and some white P.
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careysub
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Quote: Originally posted by Dan Vizine | He used method 5. That's why method 6 is a no-brainer, no gold needed, same results or better.
[Edited on 18-8-2016 by Dan Vizine] |
Oh sorry, I misread the lead-in sentence to say "with gold". Do you have the actual reference for method 6?
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Texium
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Threads Merged 18-8-2016 at 08:18 |
Fleaker
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I did indeed use gold. It works. I did it in 1 cm quartz tubes with very thick walls and still had I think 2 ampoules out of 8 or so pop on me and I
did check them with polarized glass for cracks. I used both a rotary vane/Pirani and diffusion/IC to pull and measure the vacuum. I think after it
was pumped down I put the bottom into LN2 and flame sealed the top. It's really alarming to flame seal thick wall quartz as the heat required is
rather substantial. I think this was maybe back in 2008 - 2012. I can't remember for sure, I know I got the PDF about it from iamthewaffler and the
paper was somewhat fresh off the presses then. He sent me two papers. Those two were the ones I sealed with CH4/O2 not H2/O2 so that seemed to be all
the difference
I made the SnI4 also. The gold recovery made a stink of phosphine, I do remember that. I think I boiled it all in HCl then filtered and went to aqua
regia before precipitating the gold back with SO2.
If no gold is required, and you're honestly doing this in Pyrex--I'd be willing to give this another go. Dan, I can order in some very heavy wall
large diameter pyrex or vycor and try for bigger crystals in my large tube furnace, which is also built like a brick crap house.
Neither flask nor beaker.
"Kid, you don't even know just what you don't know. "
--The Dark Lord Sauron
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MrHomeScientist
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rgbco on eBay is selling some very beautiful (and very expensive!) samples of black P - http://www.ebay.com/itm/BLACK-PHOSPHORUS-CRYSTALS-15-10-gram...
If nothing else, they qualify as some very Pretty Pictures.
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Dan Vizine
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I temporarily lost this thread.
Meanwhile, travel demands are currently the worst in my working lifetime. Company grows, US workforce doesn't ==> work more hours every damned
month. I feel like I'm stuck in amber.
I went back and reviewed all the posts for info that I may have missed. There were some fine points, details that need clarification.
Fleaker, I must not have explained myself very well. If I gave the impression that I was going to attempt this in borosilicate, sorry. That is not my
intention. It couldn't work, Quartz is absolutely needed.
Fleaker, you also made several other statements that caught my eye...
1) "Similarly, if he doesn't have ultra high purity red phosphorus, he will also fail."
I noticed that the syntheses used 99.999+ % red P. Since the products were intended for electronic investigations, it wasn't clear if the UHP was used
for this reason or if it was required for a successful reaction. Is your finding that UHP red P is needed for a good synthesis? If so, I'm out of the
game before it even begins. I'm finding it difficult to find any red P, let alone UHP.
2) " It is blinding work with quartz, but aside from the heat, it's more forgiving than borosilicate. "
More forgiving in what way?
3) Reading between the lines, I get the impression that you feel that a very good vacuum level, better than a two-stage mechanical pump can provide,
is a key to success? Am I correct in this feeling? Again, this is a crucial point to me. I won't have anything but a two-stage pump. This is
confusing. It isn't as though we need a vacuum for the vapor transport, because the tubes are actually pressurized.
Other statements that caught my eye...the idea of a refractory metal tube...
This has several hidden implications. How would it be sealed under vacuum? What seal would remain vacuum-tight at the prevailing conditions? How best
to deal with the oxidation of the tube exterior? Mo won't be good at these temperatures in air for days in a row. The gold-free variant at least
addresses the alloying issue.
Ultimately, I believe Fleaker is right about quartz being the best alternative.
Another statement backs up my pre-existing belief that oxyhydrogen is needed. The failure of the two tubes that were sealed with a C-containing fuel
gas in Fleaker's work seems more than coincidental. I read (somewhere) that normal fuel gasses leave surface contaminants and make weaker seals.
The thing that is boggling my mind is the size of the RGBCO and Smart-Element samples. How?? They suggest this was made similarly to the quartz tube
procedure (near atmospheric pressure). But the rest of the world makes this stuff by the gram or smaller. And these guys make samples up to 15 grams??
I will tell you some things you won't find in the literature....
a)My friends at Chapel Hill are interested in the electronic applications.
b) They initially bought black P from Smart-Elements when they were selling 1 g and smaller samples years back.
c) When Smart-Elements started advertising these big 10 and 15 g samples, Chapel hill found the material unsuitable for use. They never set out to
make their own black P, it was done out of necessity.
So, there is SOMETHING different about these larger pieces. But they clearly ARE NOT amorphous black P, they're highly crystalline. So, ??? I just
don't understand....
And finally...I see WHY I lost this thread. It's in "Reagents and Apparatus Acquisition" ??! This thread may peripherally touch on these points, but
isn't this a SYNTHESIS topic? If not, I'm posting in the wrong place. Please consider moving this to a more appropriate spot. If this thread isn't
meant to be about making black P, only about obtaining materials, I could start "The preparation of black phosphorous" as a new topic in the
appropriate spot so that it gets a good volume of creatively useful traffic.
[Edited on 29-12-2016 by Dan Vizine]
"All Your Children Are Poor Unfortunate Victims of Lies You Believe, a Plague Upon Your Ignorance that Keeps the Youth from the Truth They
Deserve"...F. Zappa
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Texium
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Quote: Originally posted by Dan Vizine |
And finally...I see WHY I lost this thread. It's in "Reagents and Apparatus Acquisition" ??! This thread may peripherally touch on these points, but
isn't this a SYNTHESIS topic? If not, I'm posting in the wrong place. Please consider moving this to a more appropriate spot. | You got it!
Also, I would recommend adding this thread and others that interest you to your favorites list, that way you'll always be able to find them. Just
click Add to Favorites at the top left of the thread. Then you'll be able to find them by going to your User Control Panel, and the favorites page.
[Edited on 12-29-2016 by zts16]
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Texium
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Thread Moved 29-12-2016 at 08:15 |
Dan Vizine
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Thank you on both points zts16!
"All Your Children Are Poor Unfortunate Victims of Lies You Believe, a Plague Upon Your Ignorance that Keeps the Youth from the Truth They
Deserve"...F. Zappa
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clearly_not_atara
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Quote: Originally posted by MrHomeScientist | Let's say I just want to make a small amount of black P for display in my element collection. How does the bismuth method (#3) work? Do you have more
details? It sounds exceedingly simple, and could make a nice video that others could try. I have lots of Bi and some white P. | I looked into this extensively. The problem really isn't bismuth, it's that red phosphorus will not dissolve in bismuth, so white
phosphorus must be used, and crucially, the white phosphorus must be free of red phosphorus, which means you either have to prepare it in the
dark or in situ, either version requiring a complex apparatus and far more work than it sounded like initially.
Köpf et al 2014 has better plans. Here is the full paper with pictures. But the use of an evacuated ampoule is highly discouraging.
I am actually wondering if it might be possible to react carbon with phosphates and condense the vapor into a solvent containing tin (II) iodide. Of
course there's an awful lot of "solvent" involved but chloroform is much cheaper than black phosphorus. No reason to distill phosphorus twice when
it's already produced as a vapor in the first place, right?
It appears the key catalyst is SnI2. However this will disproportionate at room temperature. So the solvent will have to be hot enough to support some
concentration of SnI2 at equilibrium. Hopefully this is not *too* hot.
EDIT: SnI2 has exothermic heat of solution in some solvents, including DMF and DMSO, which may be good (or bad):
http://www.sciencedirect.com/science/article/pii/00221902788...
[Edited on 21-3-2017 by clearly_not_atara]
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Fleaker
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Quote: Originally posted by Dan Vizine |
I temporarily lost this thread.
Meanwhile, travel demands are currently the worst in my working lifetime. Company grows, US workforce doesn't ==> work more hours every damned
month. I feel like I'm stuck in amber.
I went back and reviewed all the posts for info that I may have missed. There were some fine points, details that need clarification.
Fleaker, I must not have explained myself very well. If I gave the impression that I was going to attempt this in borosilicate, sorry. That is not my
intention. It couldn't work, Quartz is absolutely needed.
Fleaker, you also made several other statements that caught my eye...
1) "Similarly, if he doesn't have ultra high purity red phosphorus, he will also fail."
I noticed that the syntheses used 99.999+ % red P. Since the products were intended for electronic investigations, it wasn't clear if the UHP was used
for this reason or if it was required for a successful reaction. Is your finding that UHP red P is needed for a good synthesis? If so, I'm out of the
game before it even begins. I'm finding it difficult to find any red P, let alone UHP.
2) " It is blinding work with quartz, but aside from the heat, it's more forgiving than borosilicate. "
More forgiving in what way?
3) Reading between the lines, I get the impression that you feel that a very good vacuum level, better than a two-stage mechanical pump can provide,
is a key to success? Am I correct in this feeling? Again, this is a crucial point to me. I won't have anything but a two-stage pump. This is
confusing. It isn't as though we need a vacuum for the vapor transport, because the tubes are actually pressurized.
Other statements that caught my eye...the idea of a refractory metal tube...
This has several hidden implications. How would it be sealed under vacuum? What seal would remain vacuum-tight at the prevailing conditions? How best
to deal with the oxidation of the tube exterior? Mo won't be good at these temperatures in air for days in a row. The gold-free variant at least
addresses the alloying issue.
Ultimately, I believe Fleaker is right about quartz being the best alternative.
Another statement backs up my pre-existing belief that oxyhydrogen is needed. The failure of the two tubes that were sealed with a C-containing fuel
gas in Fleaker's work seems more than coincidental. I read (somewhere) that normal fuel gasses leave surface contaminants and make weaker seals.
The thing that is boggling my mind is the size of the RGBCO and Smart-Element samples. How?? They suggest this was made similarly to the quartz tube
procedure (near atmospheric pressure). But the rest of the world makes this stuff by the gram or smaller. And these guys make samples up to 15 grams??
I will tell you some things you won't find in the literature....
a)My friends at Chapel Hill are interested in the electronic applications.
b) They initially bought black P from Smart-Elements when they were selling 1 g and smaller samples years back.
c) When Smart-Elements started advertising these big 10 and 15 g samples, Chapel hill found the material unsuitable for use. They never set out to
make their own black P, it was done out of necessity.
So, there is SOMETHING different about these larger pieces. But they clearly ARE NOT amorphous black P, they're highly crystalline. So, ??? I just
don't understand....
And finally...I see WHY I lost this thread. It's in "Reagents and Apparatus Acquisition" ??! This thread may peripherally touch on these points, but
isn't this a SYNTHESIS topic? If not, I'm posting in the wrong place. Please consider moving this to a more appropriate spot. If this thread isn't
meant to be about making black P, only about obtaining materials, I could start "The preparation of black phosphorous" as a new topic in the
appropriate spot so that it gets a good volume of creatively useful traffic.
[Edited on 29-12-2016 by Dan Vizine] |
Sorry I didn't see this. I got into car accident few months back and a facility move and bunch of work.
Anyway, when I did this I used gold. I tried with cheap technical red phosphorus and never got any black P with it. I never got very big black P
crystals. Was trying some ramping in a box oven, not a tube furnace. I will try the inclined tube furnace one of these years. I do remember when
refining the gold for reuse that if I went right into aqua regia with it, there was no phosphine produced.
Kurt sent me some red P that was low grade for me to work with. I just haven't had the time to mess with it.
Quartz is more forgiving in that it doesn't really thermally shock. It also requires a hell of a lot of heat and thick wall quartz tubing is a must
due to pressure. I had several explode ampoules explode on me.
Not only is it that it leaves fuel contamination (though most quartz is lean flame), it's more the fact that oxymethane wasn't as hot. I have a MUCH
bigger torch (melted 400 g of Pt with it in a pop) so getting the ampoule liquid at one end is no problem!
Go talk to Jack at Technical Glass Products. They're awesome. They even have some sort of pressure advice on their website. You have to get a great
seal on the ampoule for it not to explode.
I also was using a rotary vane and diffusion pump. I think I had a Pirani gauge and a cold cathode.
Neither flask nor beaker.
"Kid, you don't even know just what you don't know. "
--The Dark Lord Sauron
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clearly_not_atara
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Quote: | It also requires a hell of a lot of heat and thick wall quartz tubing is a must due to pressure. I had several explode ampoules explode on me.
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I think that's why they were evacuating their ampoules. If anyone can figure out a way to do that at home though I'd be pretty impressed. Maybe you
can put a piece of Mg in the ampoule as a gas scrubber? It reacts with both oxygen and nitrogen...
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