Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
 Pages:  1  2    4    6
Author: Subject: Perchlorate manufacture (not) with Graphite
Xenoid
International Hazard
*****




Posts: 775
Registered: 14-6-2007
Location: Springs Junction, New Zealand
Member Is Offline

Mood: Comfortably Numb

[*] posted on 2-7-2007 at 14:49


Yes, unfortunately my primary interest has now become the journey.... :D

The combination of thermal + chlorate + disproportionation + perchlorate sort of scares me, so no I havn't tried it, but I am aware of the process!

Xenoid
View user's profile View All Posts By User
Rosco Bodine
Banned





Posts: 6370
Registered: 29-9-2004
Member Is Offline

Mood: analytical

biggrin.gif posted on 3-7-2007 at 00:43
more on baked cobalt spinel US4368110


The idea of a possible baked coating on graphite keeps coming back to a cobalt spinel as something more likely
to stick to graphite , less likely to flake off , and more
resistant to chemical attack in a perchlorate cell .

I have been reading patents related to these cobalt spinel
coatings and found another Dow patent which shows a
series of test coatings which were actually baked onto a
frosted sandblasted pyrex glass substrate . If this tertiary
spinel formed from the baked nitrates of cobalt , zinc , and magnesium in a molar ratio of 6:2:1 will stick to glass then it
is likely it will stick not only to graphite but even more likely it will stick to a porous ceramic , or perhaps sinter and cement
together particles of itself having been formed in bulk powder separately , or better yet might be used to cement doped tin oxides into a massive anode which can be sintered , cemented together at a reasonably low temperature .

*If* the conductance value stated in the patent has been calculated for a cubic centimeter , ( I am not clear on their measurement result , is the mho value for a square cm of the conductive film , or calculated for a cubic cm of the film from its known thickness ? ) .......
This stuff isn't conductive enough to use en masse alone ,
but possibly it could also be used to cement together particles of metal , in a sort of metal / spinel composite .
The metal would provide the needed conductivity and the
tertiary spinel would provide the chemically resistant continuous phase matrix .

Ebonex .... move over .
Here's a new conductive ceramic substrate . ( Maybe )

Twospoons ought to love this one :P


[Edited on 3-7-2007 by Rosco Bodine]

Attachment: US4368110 Zinc and Magnesium Substituted_cobalt_oxide_tertiary_spinel.pdf (152kB)
This file has been downloaded 537 times

View user's profile View All Posts By User
Rosco Bodine
Banned





Posts: 6370
Registered: 29-9-2004
Member Is Offline

Mood: analytical

[*] posted on 3-7-2007 at 14:44
Antimony doped Tin Oxide / MnO2 tertiary composition


@ Xenoid

Here's something 100% OTC that might stabilize the baked MnO2 on graphite .

From US2564707 which also charts the conductivity for various Sb doping percentages on SnO2 ......

See example 2 , and 9 and 10 . The solution of example 2
applied to your baked MnO2 graphite , and then baked again , maybe three coats ......should form the ternary
composition similar to 9 and 10 . And this should be far more
adherent than the MnO2 alone .

Alternately you could try coating graphite from the start with the composition of example 2 or 9 . If this scheme follows the same pattern as does the toughening of the coating
for the cobalt spinels , then the added second and third
dopants results in a more adherent coating . These doped tin oxide compositions also reportedly stick to glass .

The antimony doped tin is good , and is OTC from the 95/5
wire solder which may be dissolved in hot HCl . Anyway
it is a logical alternative to cobalt , and should fare better than MnO2 alone .

Attachment: US2564707 Sb2O3 doped SnO2 and tertiary compositions.pdf (479kB)
This file has been downloaded 565 times

View user's profile View All Posts By User
Twospoons
International Hazard
*****




Posts: 1181
Registered: 26-7-2004
Location: Middle Earth
Member Is Offline

Mood: A trace of hope...

[*] posted on 3-7-2007 at 15:18


Spray coating onto a heated substrate looks interesting as a way to quickly build a thick layer. Wonder if it it would work with the cobalt spinels?

I think I'm going to have to put you on my Christmas card list, Rosco.

[Edited on 4-7-2007 by Twospoons]




Helicopter: "helico" -> spiral, "pter" -> with wings
View user's profile View All Posts By User
Eclectic
International Hazard
*****




Posts: 899
Registered: 14-11-2004
Member Is Offline

Mood: Obsessive

[*] posted on 3-7-2007 at 15:29


As posted earlier, you need to add some H2O2 to the 95/5 solder dissolved in 10-12N HCl to get the antimony residue to dissolve and convert the SnCl2 to SnCl4, otherwize you will get an insoluble precipitate. Yellow SbOCl3 color remaining persistent after 1 hour at 90-95C indicates enough H2O2 has been added.
View user's profile View All Posts By User
Rosco Bodine
Banned





Posts: 6370
Registered: 29-9-2004
Member Is Offline

Mood: analytical

[*] posted on 3-7-2007 at 16:40


Quote:
Originally posted by Eclectic
As posted earlier, you need to add some H2O2 to the 95/5 solder dissolved in 10-12N HCl to get the antimony residue to dissolve and convert the SnCl2 to SnCl4, otherwize you will get an insoluble precipitate. Yellow SbOCl3 color remaining persistent after 1 hour at 90-95C indicates enough H2O2 has been added.


Yeah the ratio of Sb to Sn has to adjusted to optimum also ,
and IIRC you have already described how to do that .
We need to collect and condense the finer points of this
collective research into a summary member publication ,
if dann2 isn't already working on it .

There was a tertiary chromium containing doped tin oxide example #22 in the above patent which really caught my notice as a possible candidate coating for an *aluminum*
substrate , as I already posted a patent relating to a conductive chromate anodization for aluminum which might be a compatable interface . A similar thing might be possible on a stainless steel interface , as an alternative to titanium .
Likewise is #21 interesting for a possible copper substrate ,
and #17 for iron ...even if it was a temporary substrate application . #17 might also work as a baked binder for a nanocrystalline magnetite filler material .

These tertiary doped tin oxides would likely
weld by fusion nicely to any parent metal substrate which could contribute the minor oxide dopant as an indigenous , nascent surface oxide , or having the minor dopant as an already existing mixed oxide primer , as with the chromate .

[Edited on 3-7-2007 by Rosco Bodine]
View user's profile View All Posts By User
Eclectic
International Hazard
*****




Posts: 899
Registered: 14-11-2004
Member Is Offline

Mood: Obsessive

[*] posted on 3-7-2007 at 18:00


That last patent you posted, as well as the papers I referenced seem to indicate that the 95/5 Sn/Sb ratio in the solder is almost right on the money for the lowest coating resistance. Things may be a bit different for coatings on titanium baked at 450C, so some experimentation is in order.
View user's profile View All Posts By User
Rosco Bodine
Banned





Posts: 6370
Registered: 29-9-2004
Member Is Offline

Mood: analytical

[*] posted on 3-7-2007 at 22:55


Quote:
Originally posted by Eclectic
That last patent you posted, as well as the papers I referenced seem to indicate that the 95/5 Sn/Sb ratio in the solder is almost right on the money for the lowest coating resistance. Things may be a bit different for coatings on titanium baked at 450C, so some experimentation is in order.


I have been doing the calculations involving molar conversions and percentage compositions and the
95/5 alloy will be a bit rich in terms of Antimony concentration , 4.7285% of Sb2O3 dopant in the composite total , about double to three times the concentration it needs to be for a minimum resistance composition .

Example #2 of the patent is 1.4647% Sb2O3 for example which is less than a third of the antimony content of 95/5 .

For purposes of calculation the percentage of Sb2O3 derived from the antimony of a tin antimony alloy converted to the chlorides SnCl4 and SbCl3 and then to the oxides on baking ,
is 94.57% of the percentage value based on the metals .

For example , a 5% antimony / tin alloy will become a
5 X .9457 = 4.7285% Sb2O3 / SnO2 composition .

The amount of free tin to be added to dilute the antimony
concentration to whatever is desired should be easily calculable from there .
View user's profile View All Posts By User
Eclectic
International Hazard
*****




Posts: 899
Registered: 14-11-2004
Member Is Offline

Mood: Obsessive

[*] posted on 4-7-2007 at 05:47


But many of the later patents regarding Sn/Sb oxide on Ti for electrolysis anodes use 5-15% Sb. One of the most recent says 5% is optimal for lowest resistance. SbCl3 is volatile, so maybe the excess bakes off? Or maybe there is an interaction with residual surface TiO2.

[Edited on 7-4-2007 by Eclectic]
View user's profile View All Posts By User
Rosco Bodine
Banned





Posts: 6370
Registered: 29-9-2004
Member Is Offline

Mood: analytical

[*] posted on 4-7-2007 at 08:07


Quote:
Originally posted by Eclectic
But many of the later patents regarding Sn/Sb oxide on Ti for electrolysis anodes use 5-15% Sb.


Yeah I noticed one of the Dow patents US4369105 ,
concerning cobalt spinels which actually shows a conductivity related chart of a sort uses a 16.6% Sb2O3 composition .
But there is no indication that they were optimizing conductivity in regards to that percentage of Sb2O3 dopant ,
but were surveying the effect of bake times and the presence or absence of the intermediate layer . Compared
with the actual conductivity data for the different percentage
of dopant as charted in the Corning patent US2564707 ,
the test coating for the Dow patent is using more than ten times the amount of dopant which would provide best conductivity . Perhaps it is different when a titanium substrate below and a subsequent spinel layer above sandwiches the doped tin oxide intermediate layer , and some of the dopant Sb2O3 may actually leach from the intermediate layer , skewing the figure for what is an optimum percentage , in comparison with what is the case
for a glass substrate and no other coating than the doped tin oxide alone .

Quote:

One of the most recent says 5% is optimal for lowest resistance.


Actually I didn't notice which specific patents surveyed the
effect of different percentages of Sb2O3 , on an intermediate layer to find the optimum for conductivity , adhesion , ect .
I'm sure I saw one or more patent that described the adhesion value of coatings of some sort in terms of abrasion tests , but the numbers escapes my recollection and I didn't make any special note of it for later reference . If you have the patent numbers related to conductivity for the dopant percentages please share them . It was probably
in some of the ruthenium or other precious metal usage patents which I sort of scanned over more quickly and discarded for my preference and more intense interest in
alternatives which used more common and less expensive
materials . Damn I do not want to go back an reread a dozen more patents to find it again .
Quote:

SbCl3 is volatile, so maybe the excess bakes off? Or maybe there is an interaction with residual surface TiO2.


The more I think about it , the more dubious I am about any leaching effect changing the percentage of dopant so drastically for an intermediate layer . The whole matter
is probably nitpicking an insignificant detail and 95/5 would work fine as is for what we are doing . The difference in conductivity wouldn't be significant unless you were building up thirty coats of the stuff or using it for a fusible binder in some massive coating or massive composite scheme . 95/5 may not be perfect , but it's close enough for government work :D

Anyway I worked out the conversion multiplier so it can be plugged into the equation to formulate whatever modified
percentage of dopant is desired , starting from the alloy .
View user's profile View All Posts By User
Eclectic
International Hazard
*****




Posts: 899
Registered: 14-11-2004
Member Is Offline

Mood: Obsessive

[*] posted on 4-7-2007 at 10:34


I just noticed that Sn and Sb were right next to each other on the periodic chart and figured the difference in atomic weight for this application was insignificant. :D

This paper gave me the idea to add some ammonium bifluoride if I decide to deal with the additional hazard:

http://www.blackwell-synergy.com/doi/abs/10.1111/j.1151-2916...

"Thin films of antimony-doped tin oxide have been obtained by a new technique, the so-called hydrolysis deposition method, in which hydrolyzed solids are precipitated from metal fluoride solutions. Mixed solutions of SnF3 and SbF3 produce antimony- and fluorine-doped tin oxide films. The amount of antimony can be controlled in a wide range by adjusting the initial fluoride concentrations of the solution. The film containing 2.9 mol% antimony heated at 500°C has an electrical resistivity of 1.0 × 10-3Ω·cm, which is lower than previously obtained by wet-chemical techniques."

And these patents: US3865703, US3917518, US4040939

Quote:
Originally posted by dann2

Quote from US Pat. 4,040,939:
A solution for the semi-conductive intermediate coating was prepared by mixing 30 milliliters of butyl alcohol, 5 milliliters of hydrochloric acid (HCl), 3.2 grams of antimony trichloride SbCl.sub.3), and 15.1 grams of stannic chloride pentahydrate (SnCl.sub.4.5H.sub.2 O).

A strip of clean titanium plate was immersed in hot HCl for 1/2 hours to etch the surface. It was then washed with water and dried. The titanium was then coated twice by brushing with the solution described above.
The surface of the plate was dried for ten minutes in an oven at 140.degree. C. after applying each coating. The titanium was then baked at 500.degree. C. for 7 .+-. 1 minutes.

The theoretical composition of the semi-conductive intermediate coating thus prepared was 81.7 percent SnO.sub.2 and 18.3 percent antimony oxides (calculated as Sb.sub.2 O.sub.3).

End quote:


Starting with 95/5 solder, HCl, H2O2, the materials are so cheap, you could do first acid etch step and coating in the coating solution itself without any alcohol added.

Sort of like "Zinc"ateing aluminum, you would be "Tin"ateing the titanium.



[Edited on 7-4-2007 by Eclectic]
View user's profile View All Posts By User
Rosco Bodine
Banned





Posts: 6370
Registered: 29-9-2004
Member Is Offline

Mood: analytical

[*] posted on 4-7-2007 at 11:25
A reduced chloride content method


US6777477 describes a method for a 6.36% Sb2O3 doped SnO2 coating which is better than the Corning patent US2564707 in film thickness , and is also deposited on a glass substrate .

This method uses an ammonia derivative and a PVA thickener
to obtain a heavier loading . Microscopic examination of the
transparent films on glass was used as a basis for grading
the continuity and quality of the conductive films produced .
This might should have usefulness as a first coating
on titanium .

The use of a thickener was disclosed also in the Diamond Shamrock patent US4243503 Example#2 with regards to thickening of a suspension of antimony doped tin oxide which had been previously calcined from the sulfates and mixed with 50% Mn(NO3)2 . The patent also disclosed the mixing of powdered titanium into the suspension which produced the most long lasting of the tested baked coatings .

I think in particular where heavier loadings are needed like building up on a porous substrate , that these modifications could be very useful . The reduction or absence of chloride might be helpful also in experiments with alternative substrates . I keep thinking it would be wonderful if this magic could be worked on something else more commonplace than titanium ....something like aluminum perhaps .

This is probably *state of the art* for use of the 95/5 alloy
chlorides as an intermediate layer . The ammonium derivative produces a better dispersed solid solution for use of higher percentages of antimony and produces a tougher and more perfect coating . This patent was primarily intended for optical grade coatings so you know it has to produce a virtually flawless coating , and it is a recent patent .

It reminded me of an older patent US4775412 which uses
a similar but separately isolated ammonium derived intermediate , which goes into some lengthier decription
of a more involved process , which is considerabley simplified by the more recent patent .


[Edited on 5-7-2007 by Rosco Bodine]

Attachment: US6777477 Sb2O3 doped SnO2 via ammonia soluble derivative.pdf (67kB)
This file has been downloaded 1169 times

View user's profile View All Posts By User
Rosco Bodine
Banned





Posts: 6370
Registered: 29-9-2004
Member Is Offline

Mood: analytical

[*] posted on 7-7-2007 at 21:08
Spinel possible product of ignition


The possibility of forming a conductive spinel as the product
of an exothermic decomposition reaction has appeared
once again . It would be very convenient if a mixture of the
precursors decomposed with sufficient heat energy that
the desired spinel would form spontaneously , without any need for long baking of mixed oxides . The ash from ignition
could possibly be the desired spinel in a microcrystalline form .

I was reading US3711397 concerning bimetal spinels and
it was mentioned that the cobalt aluminate spinel CoAl2O4
is one of the most conductive and particularly desirable spinels .

Another patent US3066139 (attached) was recalled from an earlier post on another topic in energetic materials , concerning a high energy fuel which is a condensation product of hexamine and aluminum nitrate , which upon ignition produces a finely divided and highly active alumina as the product of a vigorous exothermic reaction . A supplemental oxidizer
can be mixed with the hexamine - Al(NO3)3 to increase the
energy of the reaction further , and it was my idea that
perhaps Co(NO3)2 being that added oxidizer might result
in the cobalt aluminate spinel CoAl2O4 being the product
instead of plain Al2O3 alumina as would be the case in
the absence of the added cobalt compound .

Reaching further with this same idea , it seems likely that the antimony doped tin oxide mixture which is derived from the ammonium stannate / ammonium antimonate precursors and fuses to a conductive glass , could be used as a relatively easily melted binder mixture with the preceding composition ,
to form a filled melt or sintered composite anode .

Attachment: US3066139 Hexamine Al(NO3)3 HIGH_ENERGY_FUEL.pdf (160kB)
This file has been downloaded 610 times

View user's profile View All Posts By User
not_important
International Hazard
*****




Posts: 3873
Registered: 21-7-2006
Member Is Offline

Mood: No Mood

[*] posted on 8-7-2007 at 00:19


Why not just go with cobalt oxide, Al powder, and say ammonium nitrate, aluminium nitrate, or a basic aluminium nitrate? or the oxalate

CoC2O4 + 2Al + 2 NH4NO3 => CoAl2O4 + 2 CO + N2 + 4 H2O (or whatever CO/CO2/H2O/H2/N2/NOx mix results)

The oxalate is easy to make, the oxide tend to pick up oxygen to give "Co3O4" and then "Co2O3", which might make it difficult to get the optimal ratios just because you'd not be sure of the composition of the oxide.
View user's profile View All Posts By User
Rosco Bodine
Banned





Posts: 6370
Registered: 29-9-2004
Member Is Offline

Mood: analytical

[*] posted on 8-7-2007 at 05:30


Yeah there indeed could be several aluminum spinels possible from reactions which are similar to thermite ,
or as a parallel reaction utilizing its heat perhaps along with the heat of reaction forming the spinel .

I keep thinking that it may well be possible to have an exothemic enough reaction from specific combinations
of precursor materials that ignition of a sufficent quantity as might be useful for a modest sized anode , possibly even result in a self-melting composition . It would be something like a thermite welding / casting scheme where the composition of the oxide slag is what is the product of interest .

It's probably too easy to be true , having a powdered, instant, " anode in a bag " .....
pour it in a mold , stick a fuse in it and light it :D ,
let cool and attach wire and use .

Compared with some of baking schemes , the idea does have a certain appeal , .... steer the outcome of a reaction which certainly generates plenty of heat by itself , instead of working with more inert precursors and applying brute force external heating to them .
View user's profile View All Posts By User
not_important
International Hazard
*****




Posts: 3873
Registered: 21-7-2006
Member Is Offline

Mood: No Mood

[*] posted on 8-7-2007 at 06:04


Nickel might be able to replace cobalt in that application, making it bit less expensive. The trick is to get enough oxygen without generating too much gas that blows the hot mixture apart. Heating cobalt oxide in O2 under pressure can push the overall composition up to CoO2, although it seems to be an absorption rather than actual Co(IV); but that's not enough oxygen to form the spinel.

And lithium-doped nickel oxide is a semiconductor, add more lithium to lower the resistance. Make it with standard pottery technology, mix nickel and lithium carbonates well and heat. Not self-firing, but simple and fairly inexpensive.
View user's profile View All Posts By User
dann2
International Hazard
*****




Posts: 1523
Registered: 31-1-2007
Member Is Offline

Mood: No Mood

[*] posted on 10-7-2007 at 09:36
Some Bed Time reading


Hello,

I scanned the following from Electrodes of Conductive Metallic Oxides. Sorry about the terrible bad presentation.

http://llwolly.angelfire.com/index.html

and the adds.
You are going to have to save images and rotate.

It is essential bed time reading.

Dann2
View user's profile View All Posts By User
Xenoid
International Hazard
*****




Posts: 775
Registered: 14-6-2007
Location: Springs Junction, New Zealand
Member Is Offline

Mood: Comfortably Numb

[*] posted on 10-7-2007 at 12:22


Thanks for that information Dann2, the MnO2 stuff was interesting, I will continue my experimenting with MnO2 coating of graphite/carbon. I now have several dozen lantern battery rods, so I can make some "mini-cells", which will not be so demanding on reagent quantities. I am about to "purify" my Mn(NO3)2 by precipitating the CaSO4 remaining in solution, using BaCl2.

The following caught my eye:

"......amalgam cells at 10kA/m2 and with a distance of 3mm between anode and cathode...."

Wow!!!... I didn't realise industry used such extreme parameters!

Xenoid

[Edited on 10-7-2007 by Xenoid]
View user's profile View All Posts By User
jpsmith123
International Hazard
*****




Posts: 764
Registered: 24-6-2005
Member Is Offline

Mood: No Mood

[*] posted on 11-7-2007 at 17:27
Anybody try anything with cobalt yet?


I got some cobalt sulfate recently, so I may try to see how well the oxide can be plated onto a piece of titanium...maybe over the weekend I'll give it a try.
View user's profile View All Posts By User
dann2
International Hazard
*****




Posts: 1523
Registered: 31-1-2007
Member Is Offline

Mood: No Mood

[*] posted on 12-7-2007 at 06:26


Hello Joe,

I think you will be the first on the Cobalt front, if I am not mistaken.
View user's profile View All Posts By User
Rosco Bodine
Banned





Posts: 6370
Registered: 29-9-2004
Member Is Offline

Mood: analytical

[*] posted on 16-7-2007 at 06:56


@jpsmith123 ...

Other than that US3399966 patent which caught your notice ....please check out the possibility concerning the
cobaltous acid gotten from H2O2 and Co(OH)2 acting as a sort of "Cold Blue" on clean titanium , as a preface for any baked coatings . Cold Chromating might also have a benefit on clean titanium that is to subsequently receive baked coatings , particularly where non-chloride precursors are used .....as the cold treatment could serve to limit the thickness and oxidation state of the diffusion layer of oxides at the interface with the titanium metal ,
which will attempt to grow in thickness at the baking temperatures due to oxidation of the titanium . I am thinking that some sort of extremely thin but effective
cold treatment of titanium should greatly benefit the adhesion and conductivity of the interface with whatever heavier baked layer of oxides goes on next , especially if the precurors for those subsequent oxides require significant heating before they begin to flux and diffuse
that very thin and cold applied primer layer . I can't find any reference to this sort of strategy being used , but it would seem to be a great experiment .

You maybe could simply wear some rubber gloves and use something like a carbide grit valve grinding compound made into a paste with the cobaltous acid , and use a swath of a scotchbrite scouring pad to physically scour and polish the titanium with it and see if any visible reaction occurs . It may be so thin as to not show visible coloration , but be glass clear .....even though it is formed there as an interface , and can only be detected by electronic means later . I have no idea on this ....but
it very well could behave similarly as does a cold bluing compound as used on gun metal , and be readily apparent
as a stain on the titanium .....or it may not be visibly apparent that an interface layer is there at all , even though it has formed .
View user's profile View All Posts By User
12AX7
Post Harlot
*****




Posts: 4803
Registered: 8-3-2005
Location: oscillating
Member Is Offline

Mood: informative

thumbup.gif posted on 17-9-2007 at 19:48
Update


Fleaker sent me a teensy vial containing a smidgeon of potassium hexachloroplatinate, K2PtCl6.

Sooooo, I took a small fraction of the stuff and tossed it in about a hundred mls of water along with some muriatic acid, obtaining a weak yellow color identical to a similar strength chromate solution.

I took a strip of titanium and hit it with some negative volts, giving some hydrogen bubbles on it, and understandably, some chlorine gas from the graphite anode. Its appearance changed little. After torch annealing (during which I noticed redox behavior under the flame, identical to copper, where air oxidizes the layer into iridescent shades or the flame's radicals reduce it to metal), I had a silvery to iridescent yellow strip of titanium.

I took this piece and hooked it to some positive volts and immersed it in a solution of sodium chlorate (less than 10% Cl- I'm sure). The result, oxygen bubbles from the anode where the coating covered, and hydrogen bubbles at the cathode, in excess of the amount of oxygen (i.e. more than a factor of two). Probably there's a secondary reaction in there somewhere, and I'm betting it's perchlorate.

We'll see if it lasts the morning.

Tim




Seven Transistor Labs LLC http://seventransistorlabs.com/
Electronic Design, from Concept to Layout.
Need engineering assistance? Drop me a message!
View user's profile Visit user's homepage View All Posts By User This user has MSN Messenger
garage chemist
chemical wizard
*****




Posts: 1803
Registered: 16-8-2004
Location: Germany
Member Is Offline

Mood: No Mood

[*] posted on 17-9-2007 at 20:10


Is this treatment supposed to generate a coating of metallic platinum, or of platinum oxide?

I remember having read that electrolysis of aqueous platinum salt solutions with titanium cathodes is not suitable for making a platinized titanium anode. Platinized titanium anodes are made by electrolysing a Pt-containing salt melt with Ti cathode at a temperature of several hundred °C where the TiO2 layer is non-adherent.




www.versuchschemie.de
Das aktivste deutsche Chemieforum!
View user's profile View All Posts By User
12AX7
Post Harlot
*****




Posts: 4803
Registered: 8-3-2005
Location: oscillating
Member Is Offline

Mood: informative

[*] posted on 17-9-2007 at 20:45


Idunno. We'll see.

I guess it's a little bit of both metallic Pt and PtOx. N'maybe some TiOx for good measure. I couldn't guess how many microns, but probably not many. And who knows, there could even be Cu and Fe and Cr and Ni around. A lot of possibilities considering how little Pt is in the plating solution.

Edit: still bubbling, a few hours later. I said the anode is producing oxygen bubbles, which is probably true, but a smell test indicates ozone as well. The potential is definetly high!

Edit(2): still going today. Copper clip on the anode is substantially green; some titanium screws and busbar would be helpful here!

Tim

[Edited on 9-18-2007 by 12AX7]

[Edited on 9-18-2007 by 12AX7]




Seven Transistor Labs LLC http://seventransistorlabs.com/
Electronic Design, from Concept to Layout.
Need engineering assistance? Drop me a message!
View user's profile Visit user's homepage View All Posts By User This user has MSN Messenger
Fleaker
International Hazard
*****




Posts: 1243
Registered: 19-6-2005
Member Is Offline

Mood: nucleophilic

[*] posted on 24-9-2007 at 08:45


Why not try plating onto some nickel? Do you want me to send you some nickel as well? If you need more Pt, I could look for some chloroplatinic acid.



Neither flask nor beaker.


"Kid, you don't even know just what you don't know. "
--The Dark Lord Sauron
View user's profile View All Posts By User
 Pages:  1  2    4    6

  Go To Top