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dann2
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[*] posted on 22-9-2010 at 12:42


<center> THERE IS NOT ENOUGH WORK GOING ON AROUND HERE :P</center>


To hurry things up I lined up six cells in series to test 4 ATO Anodes that were made using SnCl2:2H2O. Antimony/Tin Solder should do as a substitute IMO for the

SnCl2 + Antimony Chloride that I used. The SnCl2 was purchased on Ebay as Tin Mordant. Antimony Chloride was made from the metal + acid + H2O2. The other two cells are Mn Dioxide Anodes that I am running for a few hours to leach out some of the 'less adhering' Mn stuff. I intend to
run them in two cells later, one being pH controlled and one not. Hopefully the pH controlled cell Anode will show a much longer liftetime?
The cells are various colours, as I connected the set up backways by mistake for about a half minute and the Copper Cathodes cast off various coloured stuff during this time.
The Mn cell have since turned a purple colour. The Anodes are 7 coats of Mn Nitrate of approx. 22 grams of wet crystals dissolved in 100ml distilled methylated spirits with colour as shown in picture. They were baked at 490C for ten minutes (seven bakes total) roughly as per US Pat No. 4072586. No other coatings.
One of the ATO coatings has since failed. It was made with water in the Ethanol which was blamed for the failure.

Dann2




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[*] posted on 22-9-2010 at 12:48


forgot six cells in series

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[*] posted on 27-9-2010 at 11:18


Hi Dann2,

Good to see you're still experimenting.

I recently found a Chinese manufacturer of conductive (boron doped) diamond powder...or at least I think they make it.

According to the following:

http://www.nanozl.com/english/product.htm

Their "grey nanodiamond powder" seems to be available with boron doping.

I'm going to inquire about it. If it's not too expensive it might be worth buying some for an experiment.
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[*] posted on 3-10-2010 at 16:50


Hello JP,

I often wondered of the Diamond powder could be put into a Lead Dioxide plating tank where it would physically incorporate itself into the LD and perhaps improve it performance. Not really a Diamond Anode but if cheap enough would be worth attempting.

I attach a patent (this patent would have been posted before somewhere or other) that states that Sn Oxide + Bi Oxide is 'useful' for Perchlorate production.(example 3 at the bottom)
I attempted the procedure without success. The Titanium was passivated before it even went into a cell.

I used Bi Nitrate (made form Bi metal and Nitric acid) + Tin Tetrachloride as per the instructions.

Is there possibly a mistake in example III ?
It states that Bi Nitrate is used (along with Tin Tetrachloride, SnCl4).
Should that be Bi Chloride (BiCl3), which would be the more usual way for making doped Tin Oxides (using Chlorides only).

I also tried adding HCl (35%) to the precursor as most of the precursors that use Chlorides only, have acid added. I had no success with that either.

I am currently trying to make BiCl3 using Tin/Bi alloy by dissolving out the Tin using HCl only and being left with a fine powder of Bi that will hopefully react to form the Chloride when I add HCl + H202.???

Perhaps you have to generate HCl gas to make Bi Chloride.

Dann2

Attachment: US 4272354 Example of SnO2 +Bi2O3 for (Per)Chlorate.mht (49kB)
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[Edited on 4-10-2010 by dann2]
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[*] posted on 5-10-2010 at 21:12


Hi Dann2,

Well the Chinese co. got back to me and unfortunately they don't make conductive diamond powder. Supposedly they referenced it on their site for purposes of comparison or something. Rats! Foiled again!

Anyway, it sure would be nice if SnO2/Bi2O3 or something similarly within reach would make ClO4.

As far as your efforts to duplicate example #3 in that patent, all I can say is, in my experience with patents, I've found that some details are often left out, or something is left somewhat vague. Possibly deliberately.

I wouldn't be a bit surprised if they failed to mention an additive used in a small quantity to protect the Ti surface during thermolysis.

As a work-around, using the Bi(NO3)3 you have now, just for purposes of a quick test of the coating for perchlorate production, what about using a piece of MMO coated Ti as a substrate?

Do you have a small piece of MMO anode lying around?

And if it works and works well, then it may be worthwhile to try some other precursors, etc.
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[*] posted on 6-10-2010 at 11:59


@dann2

You were asking over in General Chemistry about how to make BiCl3, which I can safely presume is destined to be used as a dopant for baked SnO2. Really it is likely that alcoholate derivatives or sols are likely to perform better.

You should be able to precipitate Bismuth Hydroxide Bi(OH)3 by neutralization of Bismuth Nitrate Bi(NO3)3 - 5 H2O with Ammonium Hydroxide NH4OH. Bismuth Hydroxide may then be filtered and rinsed, then added to concentrated HCl to form BiCl3. However, as a precursor for a Bi2O3 sol and dopant for SnO2 the BiCl3 is probably not the best candidate, as the BiCl3 will tend to hydrolyze to an insoluble precipitated oxychloride BiOCl upon dilution with water, because the BiCl3 is only stable and soluble in strongly acidic solution. A better strategy for producing a stable sol would be to react the Bi(OH)3 with additional ammonia to form Ammonium Bismuthate derivative which would also be compatible and miscible with a similarly made Ammonium Stannate. Ammonium Antimonate could similarly be included in small amount as a grain refiner for the DTO baked coating,
although an ammonia soluble derivative of Cobalt Acetate may be superior in that regard.



Attachment: US6777477 Bi2O3 or Sb2O3 doped SnO2 via ammnonia soluble derivative.pdf (67kB)
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[*] posted on 6-10-2010 at 14:31




Thanks for replys.

I am currently trying to make BiCl3 using Aqua Regia. It states in Kirk-Othmer that it works. Simply dissolve Bismuth and evaporate to get BiCl3:2H20. You can go on to get the Anhydrous by distilling but the hydrate will be OK for me (I think, as it is OK to have water in ATO precursor made from SnCl4:5H20 so it should be OK for BTO).
I would prefer (at this stage) to try the more common or 'garden' method of obtaining SnO2/Doped-with-something on Ti. It works easily enough with ATO (using SnCl4:5H20 + Antimony Chloride + Alcohol Solvent(some water too if you like) + HCl acid). Surly the Bismuth TriChloride can be substituted for the Antimony Chloride?
The patent used Bi Nitrate with SnCl4:5H20. Perhaps Bi Trichloride will not work, will just have to try.

Another method to make Bi Trichloride (from Kirk-Othmer) is to take Bismuth Nitrate (acid solution) and add KCl. Supposidly you can precipitate the BiCl3:XH20. The Aqua regia sounds more simply and straight forward.

I was surprised to find Bismuth metal was so stubborn (like myself) :D
It dissolved easily in Nitric acid (and Aqua Regia)



I could try something like what JP has suggested with MMO but with ATO (Antimony Tin Oxide) on Ti instead. (I actually DO have MMO lying around but I will go with the ATO on Ti)
Put ATO onto Ti, that's an easy job and works. Then start coming with some sort of BTO (Bismuth Tin Oxide) on top. Since the Ti has now been coated and will not passivate when the coats of BTO (using Tin Chloride and Bi Nitrate or some other precursor that is not required to keep the Ti passivated during the subsequent bakes) are put on top.
What ever physics/Chemistry happens in the few minutes of the baking of the first coat on the etched Ti is the difference between the Ti passivating and not passivating. That first coat is very fickle AFAICS when going with Tin Oxide.

Rambling on again.............

Dann2

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[*] posted on 6-10-2010 at 17:54


You are getting passivation, so you need something to anti-passivate the interface layer between substrate and barrier coatings.

IIRC the only chloride based precursor which had good success at anti-passivating Ti was ruthenium....but because ruthenium is so expensive a substitute dopant was sought and the cobalt spinel was found to be a promising substitute for the interface. There was some test data that by strong inference showed an even more durable interface could be gotten from a mixture of cobalt and nickel in the range of 70:30 to 50:50 based on the mixed nitrates precursor. I say inference because the tests were actually done on multiple layered coatings, rather than a single interface coat.

http://www.sciencemadness.org/talk/viewthread.php?tid=9572&a...

See this file:
Attachment: Spinel oxide coated titanium anodes-preparation and characterization.pdf (133kB)
http://www.sciencemadness.org/talk/files.php?pid=111836&...

But the effect there would tend to be additive, so it is a reasonably safe bet that a single interface coat of the mixed spinels is tougher also. The presence of nickel had also been reported as a grain refiner on electrodeposited PbO2. The antimony works a similar way with regards to SnO2 and in very small percentages there (1 or 2% of the total DTO ) it reduces the crystalline grain size and results in a smoother and denser, harder, tougher baked coating. However, so does cobalt spinel do the same even better, so it would seem like layering over a single dip and bake "interface coat" of mixed Co-Ni anti-passivated Ti substrate with a thickened undoped ammonium stannate sol would be a good strategy, as it would pick up doping from diffusion of whatever excess of free spinel was residue atop the anti-passivation layer formed on the first bake, and seal that interface in the overlayered glassy diffusion doped SnO2. Then layer after layer of Bi doped SnO2 could be applied using the PVA thickened sol of ammonium stannate and ammonium bismuthate, which builds a coating thickness at about five times the rate of anything else and should produce a pore free oxygen barrier coating. As a working coating, something of a different composition may be better, or the coating may just need to run for awhile to become active by eroding to an extent that some porosity and surface area increase occurs. All of this is theoretical but it is logical.
I actually have an idea that something of a mix of dopants may be advantageous in a DTO working coating where different dopants have different catalytic effects, and the SnO2 dopants mix could include a bit of this and that, including Sb, Co, Mn, Bi, F, and Pb as seasonings for the stew. Think catalytic multi-vitamin :D

You might try the oxalic acid etch too. I have gotten nearly all the materials and tooling to proceed with my own anode experiments...but I presently lack the bench space to put everything in operation.

Edit: I may be on a roll here so why stop brainstorming, (or stepping in it as the case may later prove to be ) :P
Anyway, for some time I have thought about the use of oxalates as a potential dopant precursor which could have advantage for killing two birds with one stone in the etching,
for being compatable with any Ti oxalate residue and / or to allow a partial "conversion coating" interface. It seems clear that the Nickel Cobaltite Spinel makes a tougher and more conductive anti-passivation interface than does the unsubstituted cobalt spinel and coincidentally the nickelous oxalate and cobaltic oxalate precursors are "valency steered"
by the selective reducing property of oxalic acid for nickel to a favorable chemical alignment for the formation of nickel cobaltite. Attached is an old JACS article which describes the reactions whereby this occurs on treating the mixed hydroxides of nickel and cobalt with oxalic acid. So this peculiar effect involving the oxalates may be worth an experiment to see if a mixed nickelous and cobaltic oxalate precursor in excess oxalic acid would perhaps make an ideal
precursor mix for a baked "one coat" Nickel Cobaltite Spinel anti-passivation layer on a Ti substrate. Also attached is a second article of possible interest regarding Nickel Cobaltite Spinel. Definitely there is food for thought and possibility involving the mixed oxalate precursor scheme and hopefully the solubilities of the oxalates are sufficient that it is workable.

Attachment: Nickel Cobaltite JACS article.pdf (335kB)
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Attachment: Nickel Cobalt Spinel.pdf (180kB)
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[Edited on 7-10-2010 by Rosco Bodine]
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[*] posted on 7-10-2010 at 18:53


Update concerning the solubility of cobalt and nickel oxalates. The solubilities in neutral solution or oxalic acid solution are very low, however both are freely solubile in a solution of ammonium oxalate made basic with ammonium hydroxide.

Therefore a basic, rather than an acidic precursor coating solution would be required using the oxalate precursors. The pyrolysis of the oxalates creates a reducing effect from evolved CO which should inhibit the growth of TiO2 and promote a spinel doped Ti suboxide interface layer.

Acetate or formate based precursors may work similarly.
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[*] posted on 8-10-2010 at 14:22
Bi doping of SnO2 precursor sol via Pytlewski Polymer


I just found something for which I have been searching,
which is a means of chemical isolation of ultra pure Bismuth metal as a reduced metal powder precipitated from solution .... a similar kind of chemical reduction as is used for producing reduced metallic copper by use of vitamin C.

See attached page from Thorpe, upper right part of page.
See attached page from American Druggist detailing the Lowe procedure for reduced metallic bismuth powder.
US3458308 describes a pyrophoric precipitated Bismuth,
and evidently Vitamin C can also be used for the reduction.
Keeping the precipitated Bismuth wet and proceeding immediately with the use of it in subsequent reaction would be a wise precaution respecting the reactivity of such material.

Evidently a reducing sugar will precipitate metallic Bismuth in ultra pure form from an alkaline solution of an alkaline bismuthate, and this should work for ammonium bismuthate using dextrose, or fructose, corn syrup, ect. to provide a finely divided pure metal dust of Bismuth as a precipitate.

This reduced Bismuth metal can then be heated and stirred with a solution of Stannic Chloride to produce a mixed sol,
wherein the Bismuth dopant for the SnO2 is chemically bound and resident in an inorganic polymer form of hydrated SnO2 which should pyrolyze to a Bi doped SnO2 coating.

This "Pytlewski Polymer" is a Bi doped SnO2 sol which can also function as a wetting agent / substitute surfactant between coatings of other materials, simply by dipping the anode into this Pytlewski Polymer and air drying, before application of other precursors. Theoretically, this material should act as a bonding agent for the other coating layers.

Attachment: pure metallic (reduced) Bismuth page from Thorpe.pdf (262kB)
This file has been downloaded 469 times

Attachment: US3890429 STANNIC_OXIDE_POLYMER_Film Wetting Agent.pdf (399kB)
This file has been downloaded 431 times

Attachment: reduced metallic bismuth.pdf (435kB)
This file has been downloaded 517 times

Attachment: US3458308_Reduced Bismuth metal powder pyrophoric.pdf (73kB)
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[Edited on 9-10-2010 by Rosco Bodine]
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[*] posted on 9-10-2010 at 11:22
What about a different approach?


If SnO2/Bi2O3 will make perchlorate, then what about the following method (substituting oxides of course). This is from one of Beer's patents and I don't recall which one:

"Niobium was degreased and subsequently provided with an oxide coating of a thickness of at least 1 micron. This can be effected either electrolytically or thermally.

Subsequently a paste was prepared of:

10 cc. ethanol
1 g. ruthenium oxide
4 g. titanium oxide

This mixture was intimately admixed, heated, sintered, comminuted, and again mixed with 10 cc. ethanol. The
resulting paste was applied to the oxidized niobium in a thin layer, and subsequently heated at a temperature of
450-700" C. This treatment was repeated until at least 10 g. of the desired mixture per m^2 was present on the
surface. A niobium plate thus treated is excellently suitable for the electrolysis of electrolytes."

Maybe the powdered oxides could be mixed and then heated in a microwave kiln, then ball milled, then either made into a paste and applied to a substrate and baked as per above, or maybe something similar to what's described in this post could be done.

Edit:

I just reread example 3 of patent# 4272354, and if I understand correctly, they're saying that just mechanically mixing the two powders together (SnO2 and Bi2O3) and apparently just sticking the mixture into the hopper of a plasma coating machine, can produce a good anode.

If that's the case, that might be the way to go - just find a plasma coating shop that does small jobs.

[Edited on 9-10-2010 by jpsmith123]
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[*] posted on 9-10-2010 at 12:30


Some worthy suggestions having good theoretical basis derived from an extensive review of the literature and having a chance of working well have been made. Will it work ? ....I do not know. I mean to find out ( regarding the Pytlewski polymer, ammonium stannate PVA thickened hydrosol, nickelous cobaltite interface, ect. ) There are already reported schemes for mixing fillers with working anode coatings to reenforce the strength, fibrous alumina was something already discussed. Silica and zirconia and TiO2 can be used too.

A lot of this discussion is becoming circular. Composition and pH of the precursors for a baked coating and "wetability" of the substrate have bearing on the adhesion of the baked coatings. The methods which I have been proposing have a good chance of resolving the identified problems.

http://www.sciencemadness.org/talk/viewthread.php?tid=8253&a...

Hydrosols are stable pH and can be adjusted in pH

http://www.sciencemadness.org/talk/viewthread.php?tid=5050&a...


[Edited on 9-10-2010 by Rosco Bodine]
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[*] posted on 12-10-2010 at 08:36
Interesting Video on Youtube - making a coated Ti anode.


http://www.youtube.com/user/NurdRage#p/u/21/BjKYiu8eKa8
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[*] posted on 12-10-2010 at 10:36


Yeah! I saw that a couple of weeks ago.

I wonder where he got the idea from? No acknowledgements though ;)

At least he admits it doesn't work very well - :D
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[*] posted on 12-10-2010 at 12:37


That guy's also got some other pretty good science related stuff on youtube.

BTW Xenoid, I'm wondering, did you happen to try anything with SnO2/Bi2O3 in any of your experiments?
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[*] posted on 12-10-2010 at 13:35


Quote: Originally posted by jpsmith123  
That guy's also got some other pretty good science related stuff on youtube.

BTW Xenoid, I'm wondering, did you happen to try anything with SnO2/Bi2O3 in any of your experiments?


Yes, he's quite a hit with the Teeny generation, have a look at some of the comments!

Nurd Rage! Nurd Rage! You're my hero, Nurd Rage! :D

I wonder if the guy is a ScienceMadness member, the betaMnO2 over Co3O4 was only described in ScienceMadness, basically Rosco's idea, I don't think it was mentioned in any of the patents.

I had a bit of a medical emergency last year and haven't been doing much. Though this year I have been playing around with perchlorate anodes, based on thermally coating commercial MMO anodes with various oxides. Seems quite promising, but I need a way to, at least semi-quantitatively, analyse perchlorate, so I can make some comparisons. Not as easy as it may seem!

Have'nt really done much with SnO2, but I may give Dann2's SnCl2 method a try!

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[*] posted on 12-10-2010 at 15:43


Well Xenoid I hope your medical issues have been successfully resolved so you can get back to some serious "sciencemadness"!

I've been putzing around with a mini-lathe and a few things electrical - but still keeping an eye peeled for any advancements in BDD technology or availability of cheap BDD material. So far to no avail, unfortunately.

In fact I now believe that, absent a major technological advancement, commercial BDD anodes will not be cost competetive with Pt based anodes (for perchlorate synthesis at least), anytime soon.

Anyway, I have a "gut feeling" that the SnO2/Bi2O3 combination might work. If Dann2 reports anything positive, I'm going to clear off some of the little bench space I have and order some chemicals.
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[*] posted on 13-10-2010 at 13:37




Hello Folks,

Hope you are doing fine Xenoid. These things come and go.
SCIENCEMADNESS is as good as any medication or doctor!


There is a blow by blow account of the SnCl2 method here:
http://www.oxidizing.110mb.com/chlorate/atocl2.html

There is a guy over on the General section fusing SnO2 (can be got in ceramics store) and NaOH. It may be another viable way to get Tin compounds OTC.

The Antimony/Tin Oxide stuff is not great for Chlorate or Perchlorate making but it is tough stuff and seems to last a long time.

I am waiting on some HCl to start making Bismuth Trichloride (via Aqua Regia). The Nitrate does not work as far as I can see.

I am currently running some Manganese Anodes in Na Chlorate cell. The Anode with Manganese Nitrate decomposed onto bare (etched) Titanium is working OK. I put on five (only, I was lazy) coats and it has now lasted 18 days at approx. 50mA per square CM. The Voltage accross cell is still steady (no sign of passivation). I will soon have to change electrolyte as Chloride is getting below 100g per liter.

There is a guy over in General dissolving Palladium. It may be worth trying in a SnO2 Anode (instead of Antimony) as Palladiium is relatively! cheap. It's about 40 quid for a gram coin. JP suggested this way back as a 'DSA'. Might be good for Perchlorate.
Pt Oxide makes Perchlorate AFAIK. It's expensive for messing about with. If you had a KNOWN working formula for an Anode it would be much more affordable.

Dann2
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[*] posted on 13-10-2010 at 20:00


This may be interesting. Ever seen a cotton candy machine ? Here is a patent US5330833 for a spun SnO2 fiber material which is ATO or DTO, depending upon the dopant material. It is derived from SnCl2 and an alcohol which are refluxed to produce the sol-gel precursor, having a sticky viscosity so great it can be drawn and spun into fibers just like molten sugar can be spun into cotton candy. Evidently it is exposure to low atmospheric moisture which very quickly causes the alcohol solvated syrupy viscous sol-gel to further polymerize, harden and set to a rigid fiber.

It is very likely that a bismuth doped formulation could also be made, or any of many different other dopants could be included also. Several forms of soluble bismuth or other dopants could be made part of a precursors mixture of this sort.

Attached also is US1935178 which describes in very general ways the conditions under which hydrous oxide gels and sols can be deliberately formed from an assortment of metal salts.

Attachment: US5330833_Tin_oxide_fiber_spun_from_SnCl2_alcoholate_derived_viscous_ sol-gel.pdf (206kB)
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Attachment: US1935178 Method Of Making Gels.pdf (501kB)
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[Edited on 14-10-2010 by Rosco Bodine]
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[*] posted on 14-10-2010 at 22:19


Well I found some SnO2 that I forgot I had. I think it came from a ceramics supply place.

Does anyone know if SnO2 will dissolve in oxalic acid?

(BTW does anyone know generally how pure are the oxides that these ceramics supply houses sell?)
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[*] posted on 15-10-2010 at 07:28


Well, pottery MnO2 might be crude ore (pyrolusite), with lots of iron. That's probably the lowest purity chemical available. Many have to be pure, otherwise they'd screw things up (for instance, iron impurity causing spots and streaks).

Something like SnO2 might be ore as well, but IIRC it's flotation seperated, which might result in higher purity than crude MnO2 for instance. If that's not good enough for its use, then it's probably refined somehow chemically. Easy way to guess: if it looks precipitated or calcined, it's probably processed; if it looks ground up or natural, it's probably raw.

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[*] posted on 26-10-2010 at 21:52


I see some are still trying to make Pb02 anodes. The good news is you can buy them. Factory make for pre chlorate production. The bad news they cost about 55 USD plus shipping and handel charges costing more.
I once asked if any one was interested a year ago, no real takers then.Oh wel....................Patl
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[*] posted on 27-10-2010 at 06:06


Hello Patsroom,

Can you refresh us on the source and price and quanity that must be ordered to get some of them. Thickness is the LD coat and what is the total surface area of the Anode. Cheers.

Been doing some Manganese Dioxide stuff. Made an Anode of Manganese Dioxide deposited onto bare Ti and it worked OK. 5 coats lasted approx. 30 days at 50mA per square cm in a Chlorate cell. (XENOID got 48 days from 10 coats + some Co coats, but CD was up at 100mA for a while). There was no pink colour at any time, just brown crud that sank to the bottom when cell was stopped.
Next Anode up was a Mn Oxide (5 coats) with two coats of Cobalt Oxide put on first. The solution turned pink as soon as the cell was started. It looks as if the Co Oxide caused the Mn to come of in its 'pink' valency state. (not too well up in valency states).
There is no need for the Co undercoat (as suspected). The time would be better spend putting on two extra coats of Mn Oxide and no need to obtain extra materials (ie. Co) IMO.

Running the (in)famous divided Perchlorate cell with a Graphite Anode. Wil report. Don't expect any breakthroughs...............................

Can't get BTO to form using either the Bi Chloride or Bi Nitrate (with SnCl4:5H20)

Dann2
More Mn testing going on.

[Edited on 27-10-2010 by dann2]
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[*] posted on 27-10-2010 at 11:48


Hi Dann2,

Thanks for the update.

Can you elaborate a little bit as to what went wrong during your attempt to make BTO, e.g., the BiCl3 wouldn't dissolve, etc.?

Also let me know if you want to experiment with palladium, maybe I can send you some Pd or PdCl2 if you don't have any.
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patsroom
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[*] posted on 27-10-2010 at 13:14


Hello, Dann2
Well like I said, the cost is $55.00 USD plus shipping and handling. For international it is possible but one would have to remember custom.
The size of the anodes are 4 inches (101.6 mm) by 4 inches (101.6 mm) of mesh with a coating of about 5/32 of an inch, give or take but should fall within 1.5mm to 2 mm. They have a hanging strap about 2 inches(55 mm) long and 1/2 inch (12 mm) wide.
The ones I have on hand all look good, and I am preparing to test them for my own use. I want to make pre chlorate in one pass from chloride.
They should handle 7.5 volts @ 50 amps well for a few years with care.
For high usage they should be good for 2 yrs. or better but I do not think most people would run them that hard.
Care must be given not to sratch the surface of course,drop, bang or even chip them would not help them very much
.
If there is interest I will sell. These are factory made as I said earlier and I would be willing to sell many as you would like to buy at a time between 1 to 20.
I will watch my U2U messager for anyone interested for awhile.

I do have a Question: Where is Swede I can not find him anywhere?
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