Sciencemadness Discussion Board

Platinum wire

Tsjerk - 13-10-2016 at 04:21

Anyone interested in platinum wire? I have 3x approximately 7 cm of about 0,2 mm (I guess). Free of cost but I can only send it within the EU.

Just post a good reason why you want to have them and they are yours.

They are leftovers from the lab I work in. They come from the electrodes from these chambers. The connections between the lid and the electrodes are completely gone, but the platinum wires are fine.

Reply fast though, as I only have excess to them until tomorrow (14 Oct) 5 pm (local time).

woelen - 13-10-2016 at 07:06

I certainly am interested. I would like to experiment with electrolysis experiments with exotic materials but I am reluctant to use my MMO electrodes for that, because that may "poison" my electrodes and may render them useless. With the platinum wires I could do interesting experiments, such as electrolysing selenites, tellurates, and other exotics to see what kind of reactions I get at the electrodes.

Pumukli - 13-10-2016 at 11:27

I would also be interested if you still had a few centimeters. :-)

Jstuyfzand - 13-10-2016 at 12:14

well if it has too go I guess my home will treat them with love and affection...

aga - 13-10-2016 at 12:35

Does this feel like steal-to-order, or is it just my catholic upbringing ?

Tsjerk - 13-10-2016 at 23:35

Sounds like they are going to Woelen! You had me at selenites and tellurates, please keep us posted on the results!.

@Aga: Don't worry, if I wouldn't give them away they would end up in the waste. I think 90% of the people walking around here don't have a clue about what the wire is made of and/or what you can do with it. They would toss it in the bin without a second thought.

Tsjerk - 14-10-2016 at 03:28

Does anyone have an idea about what 85/15 platinum/iridium would do as an anode/cathode? We have a lot of those and we trow them away before they are not suitable for electrolysis anymore.

http://www.sigmaaldrich.com/catalog/product/sigma/i0889?lang...

Sulaiman - 14-10-2016 at 04:59

please throw two in my direction. :D

according to wikipedia, the iridium hardens the platinum yet chemical inertness is maintained.

Dr.Bob - 14-10-2016 at 06:21

I have seen people throw away many very valuable items because, a) they don't know what it is worth, and b) the company does not have a mechanism to recover the value easily, and c) even if the employee figures out how to recycle/sell it, the company gets the money in many cases, and almost never thanks the employee. I have seen gold, pt, silver and many other metals and salts disposed of as waste, plus other exotic material, such as PTFE type seals, membranes, and gaskets. IBM for one, used to use $800 PTFE membrane filters to clean up isopropanol and toluene for clean room use, but then discarded them as haz waste, even though the filters had barely been used at all. It was the equivalent of using an oil filter for one trip in you car and then replacing it. Pfizer had about $80,000 of gold powder/salts disappear from a lab when they laid everyone in it off, and they later were cleaning up the empty labs. I have seen million dollar equipment bought and then sent for auction before ever getting installed, due to corporate mergers/closures/reorgs. (that was in old job, not current one where we don't have that much money to spend, ever.) One drug company built a whole clinical trial surgery suite for animal study cadiovascular testing, at $4million, then decided that they were getting out of that area and ripped the entire facility out within months of finishing it. So $100 worth of Pt is barely on the radar at many places.

Tsjerk - 14-10-2016 at 07:49

I think I will hold on to the 85/15 Pt/Ir myself. I would like to see if I can do some electrochemical reductions of organic compounds in organic solvents... The anode/cathodes I have, I only have to build a chamber that is up to the solvents.

Going to reduce some alkenes and some nitro's

Tsjerk - 14-10-2016 at 10:32

Looks like chamber doesn't it?

DSC_0018.JPG - 2.7MB

phlogiston - 14-10-2016 at 10:38

Interesting, we use the same loops in our lab but I always thought they were nickel. We already salvage platinum tubes that are used to suck cell culture medium from the flasks (but break very often because it they are thin-walled and very soft), so it would be easy to add these loops to the same waste stream. Thanks for mentioning it.

Tsjerk - 14-10-2016 at 11:27

I think this could actually work as an electrical cell. The solution it is standing in right now is 25% acetic acid, 50 % ethanol, 8,33% sulfuric acid and the rest water. Lets see if the agarose and or the tubes are still there tomorrow. 2% agarose in 1 M NaCl btw.

DSC_0020.JPG - 2.8MB

woelen - 14-10-2016 at 11:32

Platinum/iridium indeed is very nice stuff. Keep the loops yourself and do interesting experiments with them. Do not allow these valuable items to be thrown away.

Pt/Ir alloy apparently is somewhat tougher than Pt alone and its shape is more stable (it acts more like a spring, while Pt can be bent all over without moving back when the bending force is removed), but this comes at the cost of somewhat less chemical inertness. For many purposes, however, 15% Ir in the alloy is not that bad and it still is sufficiently inert.

Tsjerk - 14-10-2016 at 11:56

What I noticed is that the iridium alloy suffers less from mechanical stress. Pure platinum broke quite easily in my hands, while the iridium alloy is easy to bend and never broke in years while manipulating it regularly.

Fleaker - 16-10-2016 at 10:50

Woelen,
I would actually say that platinum-iridium and platinum-rhodium alloys are far, far more corrosion resistant than pure platinum. Oddly, the platinum lowers the corrosion resistance of the Rh and Ir and make them go into solution somewhat. Some partially dissolves, some stays in the residue and must be treated by pressure chlorination. For instance, when I go to dissolve up platinum sheet and clippings at work, they dissolve in a day or two in refluxing aqua regia. But if I take wires made from type S, R, or B thermocouple which are anywhere from 10-20% Rh on one junction, you can see the platium wire dissolve in a few hours but the other leg will take 5 or 6 days to dissolve.

Iridium is an effective hardening agent for platinum, not as good as Ru, or Rh but decent. Usually it goes from 60/70 HV to 110/120 HV but will help it work harden. Pure iridium itself is not very easily deformed. Once I melted some up and hit it with a hammer cool. Shattered like glass but also deformed the hammer!

Tsjerk, pure platinum is very ductile...it should not break and takes a lot of mechanical bending to fatigue it. Now if the platinum were contaminated with lead, it cracks and breaks. Platinum (and PtIr/Rh alloys) can be distinguished from other metals by heating it white hot and letting it cool. It looks the same before and after and does not gain or lose mass appreciably.

Does anyone think there's much use for Pt wire and foil here on SMDB? Every time I look on ebay it is going for multiples of spot price.

yobbo II - 16-10-2016 at 17:13


Platinum Iridium thermocouple wire is an outrageous price on ebay.

http://www.ebay.com/itm/Platinum-wire-010-pure-99-99-Thermoc...
10 dollars per inch for 10 thou stuff :o

http://www.ebay.com/itm/Platinum-13-Rhodium-Thermocouple-Wir...

Platinum rhodium stuff for 3 dollars per inch for 5 thou stuff :o

15 dollars per inch for 20 thou stuff :o

Morgan - 16-10-2016 at 18:18

Here's some thin stuff.
http://www.ebay.com/itm/Sigmund-Cohn-Wollaston-Wire-0-00001-...
https://en.wikipedia.org/wiki/Wollaston_wire

"Invisible Platinum Wire"
https://books.google.com/books?id=5KTmAAAAMAAJ&pg=PA193&...

woelen - 17-10-2016 at 03:21

Quote: Originally posted by Fleaker  
Woelen,
I would actually say that platinum-iridium and platinum-rhodium alloys are far, far more corrosion resistant than pure platinum. Oddly, the platinum lowers the corrosion resistance of the Rh and Ir and make them go into solution somewhat. Some partially dissolves, some stays in the residue and must be treated by pressure chlorination. For instance, when I go to dissolve up platinum sheet and clippings at work, they dissolve in a day or two in refluxing aqua regia. But if I take wires made from type S, R, or B thermocouple which are anywhere from 10-20% Rh on one junction, you can see the platium wire dissolve in a few hours but the other leg will take 5 or 6 days to dissolve.

Iridium is an effective hardening agent for platinum, not as good as Ru, or Rh but decent. Usually it goes from 60/70 HV to 110/120 HV but will help it work harden. Pure iridium itself is not very easily deformed. Once I melted some up and hit it with a hammer cool. Shattered like glass but also deformed the hammer!

Tsjerk, pure platinum is very ductile...it should not break and takes a lot of mechanical bending to fatigue it. Now if the platinum were contaminated with lead, it cracks and breaks. Platinum (and PtIr/Rh alloys) can be distinguished from other metals by heating it white hot and letting it cool. It looks the same before and after and does not gain or lose mass appreciably.

Does anyone think there's much use for Pt wire and foil here on SMDB? Every time I look on ebay it is going for multiples of spot price.


Interesting read. I always was in the impression that iridium is somewhat less corrosion resistant than platinum. But alloys of the metals may behave different than the pure metals. Anyway, good to learn about this. Is this inertness also the case for strong heating (e.g. in flame coloration experiments)?

Fleaker

Sulaiman - 17-10-2016 at 04:12

"Does anyone think there's much use for Pt wire and foil here on SMDB? Every time I look on ebay it is going for multiples of spot price."

as Pt wire and foil are so useful and expensive, yet cheap and legal to post,
I'm sure that many of us would pay spot price, what can you offer ?
electrochemistry electrodes, platinum group chemistry, catalysts, element collections ...

Fleaker - 17-10-2016 at 07:02

No, iridium is absurdly corrosion resistant. Based on my experience, if I put a cubic cm of stainless 316, one of gold, one of platinum, and one of iridium into refluxing aqua regia, the stainless would be gone within hours, the gold within a day, the platinum within a week, the iridium would be there for years. I would speculate

When I go to process it, I have to melt it with nickel/copper. A sample of that is taken and pressure digested with sodium chlorate/HCl at a few thousand PSI before anlaysis on ICP-OES. The bulk is granulated and that goes into aqua regia. The black residue remains after the nickel or copper is removed and has a much higher surface area. That gets filtered off, mixed with three times its weight in HCl and chlorinated at 500 C in a tube furnace over 6-7 h. That makes water soluble sodium chloroiridate. That can then be extracted into tributylphosphate and stripped out and precipitated as its hydroxide which is then post reduced in H2 to give Ir powder.

As for what is available---I can roll out 99,9-99,999 % pure Pt into sheet, draw it into wire, make it into salts, catalysts, etc. The issue is the profit vs time expenditure on small quantities. I'd rather stick to just stock items (i.e fine Pt wire 0.1-1 mm thickness or Pt foil) that I can just cut to length.

I'll give you an example: the invisible platinum wire, Wollaston wire, is VERY labor intensive to make and retails for 28,000-32,000 USD/gram. It gets used for odd materials science research, microscope probes, instrument cross hairs, and other exceedingly delicate things.

Morgan - 17-10-2016 at 10:09

Is there an easy way to to tell if platinum is alloyed with iridium or some other metal? The reason I ask is that I bought these platinum boats several years ago on eBay and the seller stated in the offer that he didn't know if they were pure platinum or alloyed. I heated one and it remained glowing in a methanol vapor and all but that didn't tell me much. They're three just above the round gauze/screens and they feel heavy for their tiny size.
http://www.pulse-jets.com/phpbb3/download/file.php?id=4915

[Edited on 17-10-2016 by Morgan]

battoussai114 - 17-10-2016 at 10:29

You want a non-destructive way? Maybe spectroscopy. Otherwise I'd test the chemical resistance as pointed by Fleaker.

Cezium - 18-10-2016 at 01:18

Morgan> XRF, I use it to test more expensive element samples that I bought on ebay.

Morgan - 18-10-2016 at 07:52

Thanks for the replies. It's not important, it was just a curiosity if iridium would give itself away or be able to be detected in platinum by some simple characteristic but since all the PGMs tend to have the same properties it was a long shot in asking. I don't have any project lined up for them, but I did snip the corners of one to flatten it out thinking to use it as an electrode or maybe some partial function in a platinum catalyst lighter/glow plug device such as this but very tiny and without the need for a battery while robust enough to hold up without being too fragile. I think he had NASA wind some .005ths Pt wire on a ceramic post but don't quote me.
http://www.smartplugs.com/news/aeronews0900.htm
http://www.smartplugs.com/news/Spinoff2001-SmartPlug.pdf

Here I used some platinum sponge and wire from a catalytic lighter and a piece of gold plated nickel wire to hang the tiny bead on the lip of the jar. The two piece lid allowed for tightening the lid without disturbing the "ornament" hidden and dangling from the lip. Anyway it was really fun to just eyedropper some methanol into the jar and wait about 10 seconds and suddenly the jam jar jet springs to life out of the blue running about 20 cycles per second. But the little bead and delicate wire is too fragile to last in this environment. I think the Pt wire connected to the bead is about .001 or half that. The bead heats the wire, the wire lights the methanol. The bead cannot light the methanol and wire can't heat up on its own.
http://www.pulse-jets.com/phpbb3/download/file.php?id=5206
http://www.pulse-jets.com/phpbb3/download/file.php?id=5207



[Edited on 18-10-2016 by Morgan]

Fleaker - 18-10-2016 at 13:47

Morgan, if you'd like, you can send it to me with return shipping and I can do XRF on it for you. I wouldn't say they have the same properties at all--each is unique and differs from the other in its own way.

In general, it's virtually impossible to tell by looks Pt vs PtIr without annealing and testing the as annealed hardness--Ir alloy will always be harder. You might have some luck with the electrical resistivity as well.

If you want to catalytically light stuff on fire for your application, you can get a porous zirconia tube and impregnate it with platinum black.

I also have some spare Pt ink if you want a small bit. It's last application were probably letters on some space shuttle or something :P


In other news, those $1000 induction melters on ebay...

like this one in particular,
http://www.ebay.com/itm/15KW-30-80-KHz-High-Frequency-Induct...

they can melt platinum :)

Visited a friend and melted ~1000 g chunk.

Morgan - 18-10-2016 at 20:25

Thanks Fleaker, but I don't really need to know what my boats are made of at this time. I came across this tidbit on iridium, which isn't anything more than what was discussed really.
http://www.technology.matthey.com/resources/view-questions-a...
https://en.wikipedia.org/wiki/Hardnesses_of_the_elements_(data_page)

I am curious how porous zirconia is impregnated with platinum black. I don't have any platinum black but only a gram of Adam's catalyst and palladium black. I once thought about trying to sinter some platinum powder/dust from my 5% Pt on alumina beads or 1% Pt on alumina powder onto a piece of platinum wire using electricity if that would retain the surface area? Maybe I could fulgurite my Pt powder somehow with high voltage. I fiddled with my Pd on alumina pellets drilling a hole in them on my lathe by holding/chucking them inside a tiny piece of plastic tubing and then drilling with a micro carbide drill bit from my dremel collection and stringing some .002ths Pt wire through the hole but that didn't work. My Pt wire is at least twice at thick as what the little catalytic lighters use but if you heat it up/get it going, it will light methanol of course. I should have tried my 5% Pt beads but I never got around to it.
I came across this zirconia potato peeler lamp that I hadn't read about before.
https://www.youtube.com/watch?v=uGxSwumcFtU
https://www.youtube.com/watch?v=1vCQySb6ulA
https://en.wikipedia.org/wiki/Nernst_lamp


That induction heater looks like something nice to have around.

The old days lighter before conventional matches.
http://www.ebay.com/itm/RARE-Mid-19th-c-Dobereiner-PLATINUM-...

[Edited on 19-10-2016 by Morgan]

Fleaker - 19-10-2016 at 08:18

I think you'd want some porous zirconia and impregnate with a soluble Pt salt and then give it a once over with an H2 flame would do the trick.

Can kill the flame and see if it lights it again.

woelen - 19-10-2016 at 09:15

@Tsjerk: Thanks for the wires. They arrived in good order. I'll try some experiments with them and I'll share the results.

Morgan - 20-10-2016 at 07:16

It seems like if platinized zirconia were enough to light methanol vapor without using a two step method (platinum black or sponge and fragile Pt wire combination) the people who made the self-starting lighters would have opted for that or a single Pt bead method because the wires are quite easily damaged. It's just getting around the fragility problem that's troublesome.

I could use a handwarmer platinized wick with Pt wire for starting my jam jars but there's no way that would hold up to the buffeting of combustion and the fibers would be breaking lose unlike something like a model engine glow plug that is partially sequestered or protected in a cavity of some sort.

There was a lamp in the 1800's that used a coil of platinum wire about .005ths with a battery to start the heating process and that would ignite the lamp, say mounted in a hallway. The coil also retracted from above the flame and wick mechanically after ignition. The article stated that the wire had to be thin enough to light the vapor from the wick yet not too thin as to burn out or have a short life.

In looking at this platinum black bead Ben presents, it almost appears they drilled a hole and put the wire through, as it's an irregular shaped clump of platinum black and the wire is strung off-centered somewhat. The clumps are quite fragile/friable too. It's curious how they're made, if the clumps are just pressed into that shape or sintered or the powder maybe hit with a laser for a short bit, perhaps that would be a way of forming them. Here's a good closeup of the bead. I should say on another lighter I have the "beads" are perfect little cylinder/coin/donut shaped things with a hole in the middle but still very prone to crumbling if stressed in the least.
https://www.youtube.com/watch?v=8gFqzbnUO-Y#t=29s
https://www.youtube.com/watch?v=UtkEfzpZ4Sg

[Edited on 20-10-2016 by Morgan]

Morgan - 27-10-2016 at 09:43

I wonder through some technology or brass tacks cleverness if you could subdivide the end of a piece of fine platinum wire enough times to reach a critical surface area enough so that you could light methanol vapor starting from room temperature?

Just some imaginations ...
https://www.mutualart.com/Artwork/Tied-Wire-Branching-Wall-M...
http://bronhebog.blogspot.com/2011/11/branching-out.html
https://sites.google.com/a/aaps.k12.mi.us/kulka/_/rsrc/14727...

woelen - 27-10-2016 at 12:57

I did the experiment with tellurite. The result is interesting, but not spectacular to see. I did the following:

- Dissolve some K2TeO3 in water and perform electrolysis on this with platinum anode and platinum cathode.
When this is done, then no gas is produced, not at the anode, nor at the cathode, but a current is flowing. At the cathode, black material settles at the platinum wire. At the anode, no visible reaction occurs. At the cathode, the tellurium most likely is reduced from its +4 oxidation state to the elemental state. This leads to formation of black material on the cathode wire. At the anode, the tellurite ion most likely is oxidized to tellurate ion, which is colorless. This reaction is quite special, because at the cathode, it is an anionic species, which leads to formation of a solid elemental compound. Normally, such reactions occur with cations, such as metal ions.
The black material could easily be removed from the platinum wire by immersion in 65% HNO3. It quickly dissolves in that.

- Dissolve some TeO2 in conc. HCl. This yields a deep yellow solution, containing the TeCl6(2-) ion. When this is electrolysed with 5.5 volts, then quite a large current flows through the thin wires and there is fast bubbling at both wires. At the anode, chlorine is formed (smell), at the cathode, hydrogen is formed. No elemental tellurium is formed. However, after half a minute or so, there was a very peculiar smell, which was clearly noticeable besides the smell of the chlorine. It is a very familiar smell, but I do not remember from which plant or food it is coming. It is, however, something which I know from food or plants. The smell is quite strong and quite unpleasant. I immediately stopped the experiment and opened the window and left the room for a while. This smell most likely is due to some volatile tellurium compound, maybe H2Te. Tellurium is not exceedingly toxic, but it can make you very smelly for quite a long time, so I did not take the risk of that and quit the experiment.

I also tried experiments with vanadate(V) ion in an excess of a solution of NaOH. This solution is colorless. Vanadate ion can be reduced to hypovanadate ion (V4O9(2-)) in alkaline solution. This ion has a deep brown/red color. With the platinum cathode, however, no visible formation of hypovanadate occurs, nor any metal is formed. Hydrogen gas escapes at the cathode.
Next, I stronly acidified the solution, so that it becomes acidic. This leads to formation of "pervanadyl" ion, VO2(+), which is yellow. This is no real peroxo species, it has the prefix "per", because there also is a vanadyl ion VO(2+), which is blue. I tried to make VO(2+) from the VO2(+) in acidic solution, but this also does not work. You simply get H2 at the cathode.

More experiments will follow . . .

Tsjerk - 28-10-2016 at 05:01

Good to hear they arrived.

Maybe the plant smell you are looking for is garlic? I have heard of comparisons with garlic.