Sciencemadness Discussion Board

Silver Paint

hashashan - 4-6-2007 at 22:57

I guess that belongs here.
Hey guys does anyone knows how can one make silver paint?

I already made silver powder: dissolved silver in HNO3 and then reduced the nitrate to metalic gray silver powder. (will it conduct?)

Now what i need is some glue (solvent and some sort of plastic i guess) does anyone have ideas for that?

not_important - 4-6-2007 at 23:24

For what application? The binder will depend on how you want to use it and what you want to paint it on.

Web search for something like "conductive silver paint MSDS" and you should find entries like http://www.electrolube.com/docs/msds/044/044SCP.pdf

Also might want to read the attached

Attachment: JEM-0601-118F.pdf (77kB)
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hashashan - 5-6-2007 at 00:18

Well looks nice, but in the first link i dont have anying even close to those materials. I meant something more OTC like some polymer and thinner, acetone,THF etc.

And the carbon is no good because i do need very conductive paint in order to make a connection to a PbO2 anode.

DrP - 5-6-2007 at 00:40

What polymers do you have available to you? PMMA or styrene-co-PMMA may be usefull. PMMA gives reasonable adhesion to various substrates and styrene increses the hardness a bit. not_important was right - what substrate will it be used on? This could influence your choise of polymer.

"Well looks nice, but in the first link i dont have anying even close to those materials. I meant something more OTC like some polymer and thinner, acetone,THF etc. "

If your doing it with whatever polymer you can find then I think you're on the right track - get some disolved up and disperse your silver mix into it. Play with the ratios - you obviously want to use as little of the binder as possible if you want to keep your conductivity up.

hashashan - 5-6-2007 at 01:28

Thats what i thought to do, however i dont want to waste my silver(i dont have much silver powder) so i thought that maybe some of you guys ever tried to make such paint.

The substrate will be PbO2.

PS. does anyone know whether the reduced silver from AgCl2 will be conductive? it looks really grey and not as silvery as in the commercial silver paints

not_important - 5-6-2007 at 04:53

Quote:
Originally posted by hashashan...
PS. does anyone know whether the reduced silver from AgCl2 will be conductive? it looks really grey and not as silvery as in the commercial silver paints


AgCl2 ???

Reduced by what method? Very fine silver metal is grey, flakes of silver are silvery and shiny.

In that reference, adding carbon black increased the conductivity and made the film tougher.

All of the conductive paint I've done was with water+alcohol based carriers. I've used acrylic paint medium, no pigment, as a carrier, for example http://www.danielsmith.com/catalog/reference/pages/49.asp

DrP - 5-6-2007 at 05:44

or.... just an idea... find a clear adhesive (like evo stick or an epoxy) which will bind firmly to your substrate - you could use that as a binder. Thin it down with solvent and disperse your silver in it. It sould just paint on and stick firmly.

(just so long as it adheres and doesn't remain tacky)

Just guessing here but I reckon about 15% binder would do the job for you - (give or take about 5 - 10%)

[Edited on by DrP]

hashashan - 5-6-2007 at 06:30

Quote:
Originally posted by not_important
Quote:
Originally posted by hashashan...
PS. does anyone know whether the reduced silver from AgCl2 will be conductive? it looks really grey and not as silvery as in the commercial silver paints


AgCl2 ???

Reduced by what method? Very fine silver metal is grey, flakes of silver are silvery and shiny.

In that reference, adding carbon black increased the conductivity and made the film tougher.

All of the conductive paint I've done was with water+alcohol based carriers. I've used acrylic paint medium, no pigment, as a carrier, for example http://www.danielsmith.com/catalog/reference/pages/49.asp


The reduction is quite simple. I just added some granultated zinc to the chloride in water and in a matter of about 30 minutes it all got reduced to smetallic silver. (in the end of the process i boiled the whole thing to ake sure no AgCl2 remained.)

And i just got a thought Super Glue (Cyanoacrylate) IIRC it should be conductive.. i might be mistaking though.
So ive thought to put the silver on the anode, drip a few drops of the glue and smear it all nicely.

How do you think, will it work?

not_important - 5-6-2007 at 08:06

Shiny silver paint is made with silver foil crushed up, you did a hih speed reduction and got powder.

Many cyanoacrylates are fairly brittle, and cracks will ruin your electrode. The way you just suggested is also sort of all-or-nothing, you can't test a tiny droplet and see if it is conductive after it dries. Being able to mix the paint first and test it beforehand is more likely to be successful.

I'd wrap the electrode base in copper or brass hardware cloth, if it's a thermoplastic I'd even iron the cloth into it a bit. Then paint over that with your conductive paint, that way there's copper wire every few millimeters so the paint's conductivity is less important and a single crack near the top of the electrode isn't going to run the thing.

hashashan - 5-6-2007 at 08:14

well i guess it worth a try, and the cracks dont really bother me because i will make a wide connection to all the painted area so the electricity jus need to move down from the wire through the several microns of paint onto the anode.