Sciencemadness Discussion Board

PbO2 plating surfactants... any ideas for sources?

alancj - 9-6-2007 at 14:25

So here is one surfactant I'm looking for,

Cetyltrimethylammonium bromide, CTAB

hexadecyltrimethylammonium bromide, HTAB

CAS No: 57-09-0

Molecular formula: C19H42BrN

Synonyms: acetoquat ctab, cetyltrimethylammonium bromide, CTAB, bromat, centimide, cetarol, cetrimonium bromide, cirrasol-od, cycloton V, pollacid, quamonium, softex kw

Edit: this is useful for a PbO2 plating bath

Where might one procure this surfactant in the US? There is one person selling it on the UK eBay, (calling it CETRIMIDE) but I ordered from him 7 weeks ago and I still don't have it. A total rip :mad:. sciencelab.com has it, but for some odd reason I don't want to try them unless as a last resort. I think Cole-Parmer might sell it to me... but they list it as "hazardous" and I have no way of knowing if they are going to add 50 bucks to my bill just to ship a little bottle of it until I place the order when it is too late to cancel. Other places give the usual business or institution only crap.

Any ideas?

Thanks,
Alan

Edit: Changed the thread title to reflect the fact that I'm interested in trying different surfactants besides just CTAB.

[Edited on 9-6-2007 by alancj]

[Edited on 10-6-2007 by alancj]

12AX7 - 9-6-2007 at 17:39

Huh, I was looking at a bottle of "antibacterial" detergent in the cupboard the other day and saw something like that on the label. I'll have to go get the label and see if it's still around.

Tim

alancj - 9-6-2007 at 18:53

I have come up with some products like that that seem to contain it. I wonder what the concentration is and if there is any way to extract it in a rational manner.

A few grams per liter of CTAB would be added to a PbO2 plating bath and is supposed to improve the coating (relieve internal stress I think) on top of just keeping bubbles from sticking to the article being plated.

-Alan

dann2 - 10-6-2007 at 07:22

Quote:
Originally posted by alancj
I have come up with some products like that that seem to contain it. I wonder what the concentration is and if there is any way to extract it in a rational manner.

A few grams per liter of CTAB would be added to a PbO2 plating bath and is supposed to improve the coating (relieve internal stress I think) on top of just keeping bubbles from sticking to the article being plated.

-Alan


I have used this stuff when plating.
I cannot say if it improved the coatings in my set up. My set up would have consisted of one tank which was not very big in relation to anode being made. I was not really aware of the tank size to plated-amount ratio at the time. In fact my attitude at the time was to use as small a tank as possible. Less $$$$. Not a good idea. The literature has used lots of different types of surfactant.
If using surfactant it breaks down in the tank leading to possible more problems. The main GSLD ANODE patent 'washed' the break down products from the tank contents using amyl alchohol. A lot of hassle!!!!!!

Dann2

this stuff might also work

Rosco Bodine - 10-6-2007 at 13:42




You can get a look at the closeup of the ingredient by
increasing the magnification view in the pdf attached .

Don't know how good this would hold up in a plating cell ,
and it would probably be good to use some contnuous filtration .

Actually , using the very low iron content Pb(NO3) plating bath supposedly eliminates the absolute need for a surfactant ...
which is a possible source of unwanted byproduct contamination good to do without , if you can get along without using it .

Maybe a vibrator or transducer in or on the tank or on
the anode could "shake off the bubbles" and serve a
similar purpose to a surfactant .

I even thought about one of those ultrasonic transducers
like are used in the bottom of a fog making cool mist type humidifier , would be good for giving a slippery jitter to
a surface as a mechanical sort of depolarizer ....a la the jewelry cleaner effect :D

Attachment: HY%20Spreader%20Sticker%20Label.pdf (24kB)
This file has been downloaded 775 times

Twospoons - 10-6-2007 at 18:12

Kodak Photo flow 600 contains

30-40 Water (007732-18-5)
37 Ethylene glycol (000107-21-1)
25-30 p-tert-octylphenoxy polyethoxyethyl alcohol (009002-93-1)

according to the MSDS. Its a product designed as a surfactant for film processing, to avoid water spots on drying film. Doubtless other manufacturers have similar products.

The active stuff is also called p-tert-octylphenoxy polyethoxyethanol , and is listed as a non-ionic surfactant.

[Edited on 11-6-2007 by Twospoons]

alancj - 16-6-2007 at 21:37

As it turns out, the eBay seller actually DID send the CTAB surfactant that I bought... 8 weeks ago, now. Supposedly the first one must have been lost in the mail and another one was sent after some time, but I wouldn't be surprised if the guy was just lazy and sent it after 6 weeks had gone by. He has a lot of negative feed back specifically for horrible delivery times. What are the odds that a guy know for slow shipping does it right for once and then it gets lost in the mail? I have never had anything get lost, unless this is the first time, so it just seems unlikely to me. Anyway, I got it (first or second shipment regardless) and that's all that matter right now!

Rosco, what I don't understand is how it is possible to get a decent plating of PbO2 if there is no surfactant to release bubbles that are formed from the plating. My initial crude attempts with some graphite pieces produce some really intense streaks on the surface of the plating; more like gorges and craters! Do you think that a high flow rate of plating fluid across the anode would suffice? I have also wondered what would happen if plating was done in an ultrasonic parts cleaner. Maybe it would strip the plating right off as it is formed... or it could make really hard and dense plating from the tinny cavitation bubbles smashing the plating in. Who knows? The only way to find out is to try it, I suppose.

There are some other non-ionic surfactants listed that I have seen, off the top of my head I can think of Igepal CO-880 and Igepal CO-990. Seems like there are other leveling agents and surfactants that may work that I have seen in passing... I really need to keep a summary or journal for this kind of research. It’s damn near impossible to shuffle through all the patents, journals and web pages looking for those two sentences or couple of paragraphs to see exactly what it said again. Course then that would be more rigorous and I'd never forget it anyway! I’m just too lazy some times when it comes to laser beam focused research sometimes… there’s too many tangents to be distracted by!

Thanks for the suggestions,
-Alan

Rosco Bodine - 17-6-2007 at 02:14

Quote:
Originally posted by alancj
Rosco, what I don't understand is how it is possible to get a decent plating of PbO2 if there is no surfactant to release bubbles that are formed from the plating. My initial crude attempts with some graphite pieces produce some really intense streaks on the surface of the plating; more like gorges and craters! Do you think that a high flow rate of plating fluid across the anode would suffice?


The surfactant is not strictly necessary from what I understand from the patents . From what I have been getting , See US3463707 , pH 3.9 is the bullseye for insolubility of iron contamination ...higher pH is probably okay or even better in the initial plating . And filtering of a circulating electrolyte , kept at a constant temperature
and pH and concentration is pretty much required for
a lead nitrate , beta PbO2 plating bath . If you aren't
going to go to that trouble , then you should use an acetate bath and plate the alpha PbO2 . A good flow rate for the electrolyte is something that would sweep the bubbles away . With current efficiency very high for PbO2 plating ,
there shouldn't be much gassing on the electrodes anyway ,
as the reaction mainly produces PbO2 and regenerates the acid which was the salt former for the Pb salt being electrolyzed . So it should be a pretty clean plating process ,
relatively free of gassing unless you are exceeding the current density and simply have too much voltage across the cell .
Hopefully if the rest of the factors are well controlled then
a surfactant becomes way less necessary .
Quote:

I have also wondered what would happen if plating was done in an ultrasonic parts cleaner. Maybe it would strip the plating right off as it is formed... or it could make really hard and dense plating from the tinny cavitation bubbles smashing the plating in. Who knows? The only way to find out is to try it, I suppose.



A lower frequency like from a muscle massager might be better than ultrasonic . A small motor with a set collar
on the shaft having an extra length set screw would probably
give just a bit of vibration from the out of balance condition caused by the loping of the mass of the extended set screw . Or take a grinder and make the set collar lobe shaped or out of round to do the same thing ....presto
you have a vibrator . Add a variac and you can change the speed and frequency of the vibration .

Making the vibration bear directly on the bracket holding the anode so that it is going near its resonant frequency like a tuning fork would probably be good. The coating of PbO2 is going to be electrostatically attracted to the anode , as if it was very weakly magnetic , so it should stick . A mixed oxide
"alloying" effect at the boundary probably cements the the
transition from substrate to PbO2 ....in a kind of transition zone ...it isn't a precise planar junction where one thing is stuck to another thing .....but actually a boundary layer that is a complex sort of mixed interlocking materials nano structure ....something like a mixed sediments layer , but perhaps having a more geometric structure of definite mixed
oxide compounds in some variable proportion across the depth of that boundary layer .
Quote:

Thanks for the suggestions,
-Alan

12AX7 - 17-6-2007 at 07:38

A diffusion zone would depend on how much heat you add relative to the mobility of the things.

I would expect Pb3O4 might do very little diffusion, being a spinel as Fe3O4 is, and for graphite, mild intercalation might occur, but over all I don't see why PbO2 would dissolve much of anything nor why the substrate would dissolve PbO2.

Tim

Rosco Bodine - 17-6-2007 at 10:52

Heat driven fusion solubility of the oxides isn't required for crystalline mixed oxides to form as it can be a simple redox for materials in aqueous solution from which a microcrystalline deposit forms . Baking is mainly for decomposition of any hydroxides to oxides and to expel any moisture to further drive the formation of mixed oxides which occurs well below the fusion temperatures .
And it can actually be counter productive for conductivity to take the temperature on up to a firing heat where fusion of oxides occurs ....it depends on the particular
composition and its structure how it should be handled ,
cold , or sequenced in some sort of bakeout and firing .

Even magnetite can be cold formed in various crystalline shapes and dimensions by aeration of ferrous carbonate solutions ....and this is how the pigments for toner cartridges and inkjet inks are manufactured where the pigment is indeed a nanocrystalline magnetite .....even though we generally think of magnetite as a material
formed by some pyrolytic process ....there is more than one way to skin a cat .

12AX7 - 17-6-2007 at 12:04

Redox? Well that would obviously give interfacial Fe2O3, which isn't a good thing. Fe3O4 isn't noticably soluble in any solvent, so it's not very well going to hydrate on the surface either (beyond adsorbed ions, of which H+ will be less important with pH > 2 given whatever else is in the solution at > 1 M). And yes, Fe3O4 can be formed from solution; that doesn't suprise me given its binding energy. So what, you propose that the Fe3O4 substrate is going to dissolve and magically re-plate with PbO2? That's preposterous. You haven't given an explanation or defense of your supposition.

To the best of my knowledge, plating almost always results in a transition region of almost negligible thickness (nm or less?), unless heat is involved (e.g., electrogalvanized steel vs. hot-dip which does have a noticable diffusion region and intermetallics).

Tim

Rosco Bodine - 17-6-2007 at 12:58

PbO2 is an active oxidizer .

2FeO + PbO2 ---> Fe2O3 + PbO ----> Fe2PbO4 (exist ?)

PbO would most likely be the component of a mixed oxide
with Fe2O3 ....a rouge - litharge mixed oxide where
the PbO would substitute for the FeO component of what would be magnetite ....giving a mixed oxide Fe2PbO4 .
And I would suppose other mixed oxides are possible ....
with no heat required .

You are misunderstanding that I was suggesting magnetite is an intermediate somehow . I wasn't really
considering magnetite as a substrate , but iron metal ,
leading to a substituted magnetite where lead does a similar thing as cobalt is known to do with iron to form a magnetite like compound containing both iron and cobalt oxides . I am not certain of this having been proven or reported for lead with iron ....it just seemed logical .

And yeah such a boundary layer would typically be a few molecules thick .....which is pretty thin .

Anyway PbO2 is thermally unstable so it wouldn't participate
in a fusion reaction except possibly as PbO . Might be interesting to load a crucible and see if that mixed rouge - litharge oxide will form on fusion and what electrical and chemical properties it has . Vanadium pentoxide and cadmium oxide or carbonate might be interesting additives to such a melt .

[Edited on 17-6-2007 by Rosco Bodine]

12AX7 - 17-6-2007 at 13:50

AFAIK, Pb(II) isn't one of the common spinel-formers. Probably too big. Pb3O4 happens to work because Pb(IV) is likewise similar. Offhand it appears to be almost twice as big as Zn, Fe(II), Mn(II), etc.. Over a few atoms it might form a strained layer, or as an impurity in defects, up to maybe parts per thousand.

Ya know, even if an interface compound formed, if it's only a nanometer thick, does that count as a compound? Lots of things can be put together at that scale, but that doesn't make them compounds. No, for that to be true, it would have to be something that can be synthesized en masse and analyzed by XRD, etc. And I suspect that, here, you'd only find independent phases.

PbO2 is definetly unstable, but before it decomposes it could diffuse a little. That depends on what its ionic mobility is.

Tim

Rosco Bodine - 17-6-2007 at 14:55

Try rewriting the formula PbFe2O4 and it looks better .....
much more believable :P

Lead forms a borate of similar proportional composition
to that theoretical mixed oxide I suggested above ,
where B2O3 boric oxide is substituted for Fe2O3 ferric oxide , combined with PbO to form the mixed oxide ....
substituted magnetite sort of compound I was thinking about . Boron forms substituted spinels .

Lead is most definitely a spinel former ....but how interchangeable it may be is another matter , since the
crystal structure is different , tetragonal for lead , and octahedral for the more usual spinels ....but the valencies
say it will work :D so maybe a substituted lead containing spinel is possible .

http://www.galleries.com/minerals/oxides/spinel.htm

http://www.galleries.com/minerals/oxides/minium/minium.htm



[Edited on 17-6-2007 by Rosco Bodine]

12AX7 - 1-7-2007 at 07:46

That bottle I mentioned earlier:

Shaklee(R) Basic-G germicide.

Active Ingredients:
9.22% didecyl dimethyl ammonium chloride
6.14% n-alkyl (50% C-14, 40% C-12, 10% C-16) dimethyl benzyl ammonium chloride
84.64% Inert Ingredients

It also lists all the things it kills. :P

Here's an MSDS:
http://www2.itap.purdue.edu/MSDS/docs/12557.pdf

Tim