Copper nano particles for conductive ink

[boylesg]

I was watching a youtube video on how to make copper nano particles by mixing copper sulfate solution with ascorbic acid solution.

It got me thinking how else you might be able to achieve this with some other chemicals I had laying around from my chemistry days in high school and university.

I happened to have some sodium metabisulfite and that works exactly the same as ascorbic acid in the video.

I also remember Benedict's solution for detecting reducing sugars like glucose, that is essentially copper sulfate and results in the precipitation of brick red copper.

Glucose could easily be obtained from the local chemist or supermarket.

I tried to filter out the copper with printer paper but the copper particles seemed to go straight through.

So I can safely say that it was a success I think.

I will experiment with creating some conductive paints with it and report back if anyone is interested in DIY conductive ink to save some bucks.

- - - Updated - - -

Apparently if you use gum Arabic as a binder, which is aqueous, the copper particles oxidise over time and your traces stop conducting.

Perhaps clear nail polish.....

 

[BradtheRad]

Those are nano particles sure enough, if they go through filter paper!

This project is interesting, because there is nothing else like the conductive silver pen, and conductive silver epoxy. But they each cost a bunch.

Excellent for repairing traces, attaching wires to headphone transducers, photovoltaic cells. Any surface that can't be soldered easily.

There is also the defroster-grid mending paint at the auto store. Several dollars.

If you don't use them after a couple years, they harden in the tube.

So in search of a cheaper alternative, I tried silver and gold marker pens at an office supply. Their ink does not conduct, either fresh or dry.

It would be terrific to fabricate the genuine conductive stuff at home. I don't suppose it's easy to do.