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Eclectic
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You are not using enough HCl. Your solutions are not behaving at all like what I made from 95/5 solder. Also, you may have too much H2O2. Back
titrate with Ti blue tinted SnCl2 solution until the color is stable at 90-95 C for at least an hour. Use 1 part 30% H2O2 with 3 parts 10-12N HCl as
the oxidant.
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Rosco Bodine
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Why are you even worried about titrating with a redox indicator ? I would think just to use excess H2O2 and let the temperature decompose the excess ,
would be fine .
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Eclectic
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I'm not sure how long it takes for the excess to decompose, and excess H2O2 may be one of the reasons why Dann's coating solutions gelled and made a
bad coating. Blue Ti indicator in SnCl2 is a no brainer when you are working with titanium anyway. You can use acidic SnCl2 as the pre-etch, and
make the back titrant at the same time.
SOMETHING must account for the radically different behavior of Dann's solutions and mine. I'm just trying to pin down the differences in technique.
[Edited on 7-27-2007 by Eclectic]
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Rosco Bodine
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another idea
Getting a good interface at the titanium metal without growth of the oxide layer on the titanium is a bit tricky ,
and I have an idea how this might be done using SnCl2 ...
not as an HCl solution , because HCl attacks the Ti and/or
its oxide .....but rather to use *anhydrous* SnCl2 in an organic solvent with an abrasive , and scrub the titanium
with the mixture .
I wonder if it wouldn't be useful to just work with the completely anhydrous SnCl2 gotten from heating the
the SnCl2 first to drive off all the H2O @ 110C overnight ,
and then in a covered beaker continuing the heating to fusion ~250C . When the melt has cooled to ~200C and solidified , cover it with anhydrous
glycerin , and on further cooling add some anhydrous isopropanol . Then break up
and dissolve as much as possible the SnCl2 in the combined solvent . Decant the SnCl2 solution and thicken it to a paste with diatomaceous earth or
corrundum or pumice , and use it as an abrasive scrub on freshly etched , possibly hydrided titanium with a wire brush or a scotch brite pad , wearing
gloves , and covering the titanium with the mixture in a shallow tray .
I believe this would get the surface plating of Sn at the interface which you have described , without an undesired growth of the oxide layer on the
titanium . The vapor of the isopropanol would provide a shielding atmosphere from the oxygen and moisture of the air ....allowing the reactivity of
the SnCl2 to prevail as the primary effect on the titanium .
I think the presence of HCl as solvent for the SnCl2 is going
to interfere with what you are trying to accomplish and this is possibly the way around that problem .
After the titanium is treated as above decribed , rinsed with isopropanol and dried , the next step IMO would be to apply the dip coated alkaline sol
of combined stannic and antimonic acids , as their ammonium stannate and ammonium antimonate precursors , that I have mentioned before in regards to
US6777477 . Then the substrate is baked .
Anyway .....that's my theory and proposed experiment .
Call it the star trek approach ....to go where none has gone before 
[Edited on 27-7-2007 by Rosco Bodine]
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Eclectic
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12N HCl isn't really that corrosive to titanium. Dann did an experiment for me with 25% SnCl2 in 10-12N HCl with a piece of Ti half submerged
overnight. The solution turned blue indicating SOME attack on the Ti, but there was no apparent surface corrosion, only a slight change in color,
which I suspect is due to a thin flash coat of tin.
Rosco, How did you get stuck on the idea that acidic chloride solutions are BAD in this application? Your insistance on using alkaline coatings
seems completely counterintuitive when you look at the chemistry of titanium. Dunk a piece of Ti in HCl and see for yourself how slowly it reacts.
'Course, classical physics says bee's can't fly, but they do anyway.
[Edited on 7-27-2007 by Eclectic]
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Rosco Bodine
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Apparent or not , there *is* attack of the titanium oxide by HCl at even 0.8 N HCl . I was reading the data on leakage current for valve metal
capacitors where the TiO2 layer was being used as a dielectric , and a SnO2 intermediate layer formed from SnCl2 and baking was applied ....and the
HCl concentration had to be kept minimal like 0.4 N for HCl to prevent formation of TiCl3 which trashed the dielectric layer and made the interface
semiconductive . The semiconductivity of course is our objective but it is only a narrow range of pH where that occurs productively .....
as too much HCl just becomes the primary reaction ,
eating more into the titanium metal and adding more thickness to a layer where keeping it thin and doping it not growing it in thickness is what we
want to do .
If you insist on growing the layer thickness with chlorides then you need to use Ruthenium for a mixed RuO2-TiO2 conductive oxides layer .....and just
use TiCl3 as a deliberate precursor in the dip coating .
Anyway I think I have posted this before ....in connection with the observation that the structure for the valve metal interface is a semiconductor
called a Schottky diode ,
and referencing a patent for such a device I found the only
method I have ever seen for producing a Ti *suboxide* interface not requiring a pyrolytic process with hydrogen reducing atmosphere , but using an
electrolytic anodiztion
of titanium in a basic electrolyte which was KOH , the result being a "blue titania" suboxide . Electrolysis here was being used simply to drive the
natural reaction as would occur chemically , to produce the desired effect of a very thin and controlled chemistry oxide interface on titanium ...a
"soft mixed oxide" which would be semiconductive and receptive of doping to enhance its conductivity as a PN junction in
the case of the patent .....but which could be subverted to our purpose of non-polarized semiconductivity using a different doping material ....like
SnO2 instead of PbO2 as in the patent .....and developed into a diffusion layer by baking .
This is exactly what my premise about the usefulness of an
alkaline reaction is about . It creates a stable porous and semiconductive oxide layer on the titanium substrate *directly* , while acid etchants do
not . Easier to soak dopant into a sponge than to penetrate a layer of diamond .
[Edited on 27-7-2007 by Rosco Bodine]
Attachment: US2711496 Blue Titanium Conductive Oxide Anodization.pdf (295kB)
This file has been downloaded 726 times
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Eclectic
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Can I read that capacitor reference? That's some good info.
I'm thinking that with SnCl2 in the HCl pre-etch, a flash plating of tin will cover ALL exposed titanium while the oxide is dissolved. This should
limit the reformation of a TiO2 layer.
We'll never be sure what is really going on with the surface chemistry without some fancy analytical instruments, but really it just boils down to
"try it and see if it works".
Oooh! US27711496 has a wealth of info. You haven't convinced me SnCl4 is BAD, but now I'm more willing to experiment with alkaline conditions.
[Edited on 7-27-2007 by Eclectic]
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Rosco Bodine
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You can't "see" what is going on in these nano scale layer chemistry reactions ....only detect it with instruments and then make an educated guess .
Maybe I have the dots connected wrong from what I have read and how I interpreted it ... but then what are experiments for ?
In other words ..at least we agree on something
The capacitor patent US3454473 is attached
BTW .....I know what you are meaning to happen with the Sn deposition in the etching scheme ...I just don't think it will happen in the presence of
the HCl , as the Ti will preferentially react with the HCl and the H2O also present , instead of reacting only with the SnCl2 .
What I was suggesting was a way of getting past that likely problem ......by having no HCl and no H2O present along with the SnCl2 .
You see then , there is only one reaction route and no competing reaction .
What I am describing does not seem to me at all to be counterintuitive . I am proposing something which steers the natural inclination of the
materials ( as I understand it anyway ) to produce the layer structure and chemistry that is desired , instead of trying to force formation of a layer
structure and chemistry that goes against the way I suppose the materials will react . One theory on which I am operating is that titanium doesn't
just go directly to an oxide but probably first forms a transient hydroxide which then dehydrates .....and this mechanism will predominate in anything
other than anhydrous reaction condition .
[Edited on 27-7-2007 by Rosco Bodine]
Attachment: US3454473 Titanium film capacitors.pdf (178kB)
This file has been downloaded 756 times
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dann2
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Some pictures for some light entertainment
Hello,
Some picutures below:
Note:
Paint No. 2 is:
__________________
The SnCl2:2H2O was obtained as Tin Mortant (white solid).
The 'painting' solution consisted off:>>> [Solution/Paint No. 2]
5 grams SnCl2:2H20 {2.63 grams Sn (77% of Sn/Sb ratio of final paint)
1.92 grams of SbCl3 solution {0.787 grams Sb (23% of Sn/Sb ratio of final paint)
2.2 grams 35% HCl
10 ml Iso-Propyl alcohol (surgical spirit used)
__________________________
Paint No 1 is:
_________________________
Solution consists of 16.7 grams SnCl4 (SnCl4 is 45.5% Sn)
+ 4.5 grams SbCl3 (SbCl3 is 53.4% Sb)
in 38cc liquid (HCl + H202 + Water)
Ratio is 76% Tin, 24% Antimony. [This is solution/Paint No. 1]
________________________________
Theses paints have been posted before way up the thread.
@Electic
-----------------------------------------------
I painted and baked the Ti which was left to soak overnight in HCl + SnCl2.
Put on 3 coats of 'Solution No 2' then baked and took some pictures.
There was no visible difference between the part of the Ti
that was soaked and the part that was not.
Applied another 3 coats, took some pictures!, and baked.
Due to the fact that the coating seemed to soak in water from the atmosphere this ruined
the coating when it was baked. The surface of the (unbaked second coat) anode went wet and had to be
dried with the heat gun again.
It was white in colour in places and not even over surface when baked. I did not
continue with the piece of Ti as a potential anode.
---------------------------------------------------
Made up anothe paint using SnCl4 (Made from SnCl2 + H2O2) + Ammonium Moly. in 12% HCl.
[Solution No. 5]
0.2 grams Ammonium Moly.
1.5 grams SnCl2:2H20 +H202 (min. amount added)
+ HCl. Total volume of Paint made was 7.6cc
Painted and baked. Bad coating. Did not test in Chlorate cell. Did not turn black.
No crystals visable on Ti after drying.
Water based (or HCl based if you like)
are inclined to dry in puddles. Better to have Alcohol if at all possible IMHO.
I think this paint was too dilute too.
Ammonium Molybdate forms a green ppt when added to SnCl2 if there is alot of water
in the solution. When SnCl2 is dissolved in 12% HCl this does not happen.
The solution of SnCl2:2H20 + Ammonium Moly (both dissolved in HCl (12%) before mixing)
is an orange clear colour, not unlike the colour of the 'Ti Oxide indicator stuff'.
Will try again just using SnCl2:2H20 + Ammonium Moly in a min amount of HCl + Isoproply
Alcohol. ie. will not add any H202 to convert Tin(II) to Tin(IV).
Perhaps pure IsoProply alcohol will stop the green PPT. If so
I will use no water.
Camera not great BTW. One photo out of focus/bad equipment or both. The crystals in the photo can be clealy seen as (pretty) squared on the surface of
Ti (this is before bake).
I think way the paint is appllied (dilution rate etc) may have aloth to do with getting a good coat. (my 2c worth).
http://s168.photobucket.com/albums/u200/anodes_2007/?action=...
http://s168.photobucket.com/albums/u200/anodes_2007/?action=...
http://s168.photobucket.com/albums/u200/anodes_2007/?action=...
http://s168.photobucket.com/albums/u200/anodes_2007/?action=...
http://s168.photobucket.com/albums/u200/anodes_2007/?action=...
Dann2
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dann2
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Two more attempts
Hello,
I returned to solution No. 5 and attempted to evaporate some of the liquid off by heating.
Reminder if needed__________________________
[Solution No. 5]
0.2 grams Ammonium Moly.
1.5 grams SnCl2:2H20 +H202 (min. amount added, had Ti indicator added)
+ HCl. Total volume of Paint made was 7.6cc
Orange coloured paint. When baked did not turn black.
______________________________________________
(The above solution No. 5 was posted before up the thread BTW.)
The solution changed colour from Orange (Ti Oxide indicator) to light yellow.
Oxide started to PPT. I stopped heating. A very small amount (~0.4 cc from 7.3cc)
of solvent was evaporated.
Painted and baked with the solution.
As soon as I pointed the heat gun at the painted Ti, the coating turned black.
After baking, the coating was less black but blacker that the first time I had
used this paint (before I had attempted to evaporate some solvent away).
I coated again and the same thing happened. As soon as I pointed the Heat Gun
at the painted Ti the coating went black. It is a bluish black. It may be the Ti
indicator in the paint turning blue again??
When baked the the coating was less black than when it went into oven. It looked better than first time I use the paint (up the thread) but does not
look good enough for it's intended purpose.
Did not 'test' in Chlorate cell, and probable will not.
----------------------------
New paint!!!!!!!!!
Solution No. 6
1.5 grams SnCl2:2H2O dissolved in 2cc Iso Proply Alcohol
2cc HCl (12%)added.
0.2 grams Ammonium Molybdate added to solution and the lot mixed.
Solution turned deep green/yellow with some (very little) solid at bottom.
Painted and baked.
6 coats total, 2 coats per bake, 3 bakes total.
There was no visable crystals on surface of Ti when drying with Head Gun.
The paint covered and wetted the surface well.
The baked paint was a black colour and looked good.
Electic please skip one line
Steel wool could remove coating.
Piece of plastic does not remove coating.
Have yet to 'test' in a Chlorate cell.
This looks the best coat yet.
US 3940323 uses Mo though it is an Ru based anode.
_____--------------------------------------____________
'Water based' paints seem not too good at covering surface of Ti. They do
not wet the surface and are inclined to form puddles when drying. The dissolved
solids are inclined to migrate to theses puddles and you get too much solid
when the puddles eventually dry. Hard to get even coating.
The HCl in last in puddles too where it may be etching holes in the Ti ( perhaps this does not matter) as I have seen lots of pits where the puddles
have been.
If you use small amonts of paint to stop puddles from happening it is then hard to get the smaller amount of used paint to wet the surface
successfully.
Dann2
[Edited on 29-7-2007 by dann2]
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Eclectic
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It sounds like you are trying to apply too much coating before baking. Also, the alcohol may be in the formulas to facilitate surface wetting and
rapid film drying.
Damn, this research by proxy is frustrating!
What happens if you just etch, dip coat, shake, and bake?
[Edited on 7-28-2007 by Eclectic]
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Rosco Bodine
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| Quote: | Originally posted by Eclectic
Damn, this research by proxy is frustrating! |
It's hard to find good help anymore .
| Quote: |
What happens if you just etch, dip coat, shake, and bake?
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"shake and bake" ......LOL
Oxidative soak should be looking pretty good about now 
[Edited on 29-7-2007 by Rosco Bodine]
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hashashan
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Well guys got everything ready for my PbO2 coating. except for one thing, Temperature, how the hell can i keep it at constant temperature of 55
degrees? i wont put it in the house. i dont have an oven and the differences between day and night here are quite intense and can reach up to 20
degrees difference.
Any suggestions?
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dann2
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Hello,
I have used a glass tube with a spiral of Nicrome wire in it connected to a variac. The tube was put into the plating tank and the variac adjusted to
give temp. I wanted. Open loop temp. control I guess.
An aquarium heater has been used by others.
A deep fat friar or kettle, if filled with water and connected to a variac with the plating tank sitting in it would do. Not very elegant.
If you do not have a variac a high power resistor can be made from Nichrome wire with a connection to it where it give the correct current into
kettle/deep fat friar/tube + Nichrome wire or whatever. Wastes a bit of power and you need to keep clear of it but will do job.
Insulate the tank + heater with fiber glass wool to shield against the effects of changing ambient temperature.
Do you actuall want a controller?
I made a very simple and crude controller out of a comparator IC + thermocouple connected to a relay, once, which swithed the heater on and off when
needed. Bang Bang controll, I believe, is the term for this type of control stragegy.
Dann2
[Edited on 30-7-2007 by dann2]
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dann2
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Hello,
Will solid SnCl4:5H20 dissolve in water without forming Oxides like SnCl2:2H20?
US Pat. No. 3940323 useses SnCl4:5H20 in water (+ Ammonium Mo.)
(Hooker Chemicals & Plastics Corporation)
Can anyone suggest a fairly common solvent (other than water) that will dissolve Ammonium Molybdate and is also miscible with water (easy eh!). There
probably is none but I thought I would ask anyways.
I tried Ethanol, Methanol, Iso Proply Al., Ether.
Perhaps acidified Ether?
Dann2
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Rosco Bodine
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Maybe try DMSO (dimethyl sulfoxide) , acetone , ethylene glycol , glycerin .
You could probably avoid all the chlorides related problems
if you would simply *try* the SnCl2 to SnO2 oxidative soak method for the initial coating followed by the mixed ammonia derived sols and baking . This
could put you far ahead of whatever you might try to copy from an existing patent , if it works like I suppose it may . It is also easier than what
you are still trying to do now .
[Edited on 29-7-2007 by Rosco Bodine]
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Eclectic
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Dann, this is about the 3rd time you've asked these questions going down this path...
Are we being Punked? A good game of rile up the old codgers, eh?
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Rosco Bodine
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Hard headed tunnel vision younguns are a real pain 'eh
I used to be a regalar Einstein too 'fore I grew out of it
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Eclectic
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Rosco, I read through the Ti capacitor patent, and found some good info in there about alcohols facilitating the wetting of titanium surfaces. The
idea of strongly acidic solutions chewing through the TiO2 seems to be correct too. I think I'll be happily studying the interaction of titanium
surfaces and various tin chlorides for a while, not that there might not be a better way to make an anode, but because I've gotten a LOT of the stuff,
really cheap, made from a $12 1lb roll of 95/5 solder, and a $10 roll of 97% Sn leadfree solder, balance Cu, which does not seem to dissolve in plain
31% muriatic acid and settles out as a gray colored powder.
I'm more into the chemistry than the final product.
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hashashan
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Firberglass insultaion, contorllers ... damn.
How important is tempereture vcontroll?
what will happen if the anode will be grown just at room tempererature without any insuklatoins or anything.
the temperature will vary about 27-35 degrees ?
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Rosco Bodine
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There are some patents which describe mixed alkoxides being used as the precursor for the baked oxides on titanium . And here is an abstract where
this reportedly even works on aluminum as well . If the aqueous chlorides
are not giving good results ....I wouldn't keep trying to find the niche condition that gives the desired result , but look at something different
which may not be as tricky. If baked chlorides are proving to be problematic , why keep beating
your head against the wall on that approach instead of trying something different which might work even better ?
I can't prove that the things I have been saying are certain ,
but from the references available my interpretations are logically justifiable .
Abstract of JP2007070673
PROBLEM TO BE SOLVED: To provide an electrode which is inexpensive, can be adapted to various systems, and has a desired shape, for instance, an
electrode having a structure consisting of an aluminum substrate and an antimony-containing stannic oxide film formed right on the substrate.
SOLUTION: The structure comprises: the aluminum substrate which is obtained by preparing a coating liquid containing a tin alkoxide and an antimony
alkoxide, applying the coating liquid onto the aluminum substrate, drying the applied liquid and baking it; and the antimony-containing stannic oxide
film formed right on the substrate.
COPYRIGHT: (C)2007,JPO&INPIT
BTW , if you are going to pursue the chlorides route anyway ,
one of the things you might try is adding some NH4NO3 to the HCl when dissolving the solder . The aqua regia formed in situ might facilitate the
solution and serve a similar function as H2O2 without added water , and the presence of ammonium salt might enhance the solubility and even provide
some possible complexation . Some small amount of Zn added might also be of benefit . The byproduct NH4Cl and the ZnCl2 as well are also fluxes
whose presence might be beneficial .
[Edited on 30-7-2007 by Rosco Bodine]
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dann2
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| Quote: | Originally posted by Eclectic
Dann, this is about the 3rd time you've asked these questions going down this path...
Are we being Punked? A good game of rile up the old codgers, eh? |
?? Greetings old codgers, (thanks for the compliment )
Apologys about the post, I was rather tired and not thinking too straight. Is it only the 3rd time....
The latest coating (solution/paint No. 6) on Titanium passivated soon after placing coated Ti into Chlorate.
Same goes for Solution/paint No. 5 that was heated in an attempt to evaporate off some solvent.
Dann2
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dann2
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Hello,
What are Alkoxide's? Is an 'Alkoxy-Tin' compound the same?
Will I not need SnCl4 (anydrous) in order to obtain the Alkoxide. ie. back to square one.
A few of the patents doing the rounds have used the Alkoxy-Tin to obtain a coating for the
electrolysis of brine without any coating on top. They refluxed SnCl4 (anhydrous) with
n-amyl alcohol for some hours to obtain the Alkoxide. eg. US 3627669 Example 4,
US 4040939 Example 6.
Regarding one of those's question I have asked before:
From US 3,940,323 Example 1:
___________________________________________________
snip
A solution of 2.2 parts of SnCl4:5H2O and 0.2 parts of (NH4)2MoO4 in 5 parts of water is brushed on to
the cleaned titanium surface.
snip
___________________________________________________
Will Oxides of Tin not ppt when the Tin(iv) Chloride is put into the water?
Just trying to pick holes in those's patents or am I shooting myself in the foot.
snip from post by Rosco
Getting a good interface at the titanium metal without growth of the oxide layer on the titanium is a bit
tricky, and I have an idea how this might be done using SnCl2 ...
Snip
The problem of my DTO coatings is not that a Ti Oxide layer is forming between the DTO and the Ti
substrate (unless perhaps the very poor paints that did not even turn black)
but that the DTO will not stand up to Chlorate cell anodic conditions. The coating wears away as
soon as the DTO coating is exposed to Chlorate cell electrolyte with current flowing.
They will work as an anode for some minutes with a smell of Chlorine but the coating gets eaten away,
the Ti gets exposed and then the Ti Oxide layer appears.
Hashashan
Most of the patents say that the coating of Lead Dioxide has a higher quality if the temperature is raised up from Room Temperature.
What sort of heater have you available? What is the plating tank made from?
Could you use a 'slow cooker' hotplate underneath the tank?
A large container of Cooking oil with a heating element in it with the plating tank sitting it?
The fiber glass insulation will be good to shield the set up from the varying ambient temperature but it
is not essential. Run the heater for the tank for a few hours to see where the temperature goes and how
stable it is. It may be good enough without the fiberglass.
Dann2
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hashashan
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I can get a heater, the heater is not a problem, i can buy a wire, use some primitive type of a stove or anything like those, oh yeah i can use a
thing i once used... placing a candle under the tank  (the candle does keep it in
a good temp at night but at day it gets too hot.
The main tank is just a chemical glass (600ml) i think it is a good tank, no need for anything else.
The problem with all those heaters is that i cant sit by the electrode for 2 days and watch it getting plated, and it does get really hot here at
daytime.
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Rosco Bodine
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| Quote: | Originally posted by dann2
Hello,
What are Alkoxide's? |
Generally an alcohol which has a metal substituted for the hydroxyl group hydrogen . Also called alcoholates , and sometimes perhaps less accurately
for this arrangement "esters" . It is an organometallic compound which can be dissolved in organic solvents , may itself be a volatile liquid and can
be hydrolyzed to the metal oxide by water or dilute acid , or by heating sufficiently . They are generally basic , alkaline in nature . Sodium
methoxide is probably the simplest example .
| Quote: |
Is an 'Alkoxy-Tin' compound the same? |
Yes .
| Quote: |
Will I not need SnCl4 (anydrous) in order to obtain the Alkoxide. ie. back to square one. |
Not necessarily , other precursors , even the free metal can be used .
| Quote: |
A few of the patents doing the rounds have used the Alkoxy-Tin to obtain a coating for the
electrolysis of brine without any coating on top. They refluxed SnCl4 (anhydrous) with
n-amyl alcohol for some hours to obtain the Alkoxide. eg. US 3627669 Example 4,
US 4040939 Example 6. |
You mean to tell me that a DTO precursor which is *alkaline* in nature can actually be used instead of a chlorides precursor , where the chloride is
there to flux and etch the
titanium ???? Well imagine that ...must be a misprint or something , huh
???: Actually you will likely find the alkoxide based coatings in the earlier patents
, where it was probably used first as a butoxide , later as an ethylene glycolate , or a glycerylate . The theory was probably that the molten
organic material afforded some blanketing of the titanium at up to ~200C , whereupon the precipitation of SnO2 would begin , and the formation of a
solid solution of TiO2 in the SnO2 would commence ....limiting the growth thickness of the TiO2 layer and modifying its chemistry . What a novel idea
! There might even be other better ways of going about that
| Quote: |
Regarding one of those's question I have asked before:
From US 3,940,323 Example 1:
___________________________________________________
snip
A solution of 2.2 parts of SnCl4:5H2O and 0.2 parts of (NH4)2MoO4 in 5 parts of water is brushed on to
the cleaned titanium surface.
snip
___________________________________________________
Will Oxides of Tin not ppt when the Tin(iv) Chloride is put into the water? |
Let me guess ....you follow the patents description and you get a precipitate when the described mixture is prepared ?
| Quote: |
Just trying to pick holes in those's patents or am I shooting myself in the foot. |
If there was any neglect in describing the mixture as being a "clear solution" , then you shouldn't be surprised to get whatever you have gotten
.....since they left the door wide open to whatever it may be . This is a good example of the ambiguity of "patent speak" in "described examples"
which may not be a precise blueprint which you can follow verbatim . Sometimes yes ....sometimes no . What might take ten pages of detailed
decriptions to represent a full technical disclosure may have been pared down to three pages by the lawyers who wanted to tell only as much as
required to legally claim a technology .
| Quote: |
snip from post by Rosco
Getting a good interface at the titanium metal without growth of the oxide layer on the titanium is a bit
tricky, and I have an idea how this might be done using SnCl2 ...
Snip
The problem of my DTO coatings is not that a Ti Oxide layer is forming between the DTO and the Ti
substrate (unless perhaps the very poor paints that did not even turn black)
but that the DTO will not stand up to Chlorate cell anodic conditions. The coating wears away as
soon as the DTO coating is exposed to Chlorate cell electrolyte with current flowing.
They will work as an anode for some minutes with a smell of Chlorine but the coating gets eaten away,
the Ti gets exposed and then the Ti Oxide layer appears. |
Your test may not have validity since the ATO is not really a working anode coating , but an intermediate layer . Still it would seem that days would
be more expected than minutes for the coating to fail . I'd try baking on some
cobalt spinel over the outside . Everything you have described sounds like porosity is what you are getting rather than a sealed vitrified continuous
coating of ATO . I really think that is what you will continue to get with any chlorides based precursor system applied alone in a coat and bake
sequence like you are doing ...believing you are following a "recipe" which is likely a greatly abbreviated description from what was actually done .
I think you are pursuing an exercise in futility where hope springs eternal for solving a puzzle for which you do not have the missing pieces ,
particulary in regards to any one patent . There is no
single "magic anode patent" , but you may learn the elements required from several different patents , and then
put them together to accomplish what you want to do .
I have personally done a lot of experiments which have been inspired by patented processes .....and usually find ways of improving , refining process
examples where they don't tell you the whole story ... as they may leave that for them to know and for you to figure out
Personally I think the chlorides based precursor strategy
is useful in a limited context , not fully described and not as simple as following any single patent example as a good stand alone recipe . What I
am getting at is step one may come from one patent , step two from another , step three from yet another ....and so on . That's the *only* way you
will put the pieces of the puzzle together .
[Edited on 31-7-2007 by Rosco Bodine]
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