[NewCandle] Silver dendrites

[Keith Nagel]

Hey Nick,

What I found working with electrodeposition of silver was that
silver _really_ wants to grow in this form. As you lower current
density, the plating is more compact and solid, but looking under
the microscope you can see a giant forest of these "trees".

Commercial plating baths are generally done with the cyanide salt.
The cyanide ion is adsorbed on to the growing tip of the dendrite
preventing further accumulation of metal and allowing lower lying
fresh metal to plate. Other organic materials are sometimes used
to achieve the same result.

The putative transmutation process that we would be investigating
takes place over months, with very low current density. This
would typically produce a very flat uniform plate were we using
another metal. But with silver, even the most feeble of currents
can produce dendrites. My feeling at the time was that this
odd combination of factors ( low current density + dendritic growth ) might
help to produce the novel result.

I'll send you a sample of silver nitrate. I can send some test strips
of aluminum as well, but I worry that the mailing process might destroy
the rather delicate structure we want to study. BTW, just how rough
is the prep process to image these samples?

Also, to be clear, what I'm curious about is the microstructure we
will see on the aluminum surface after the displacement reaction has
occurred and a small amount of silver is deposited. As we have
seen from you first micrographs, the surface structure is complex
( oxide layer and metal ) and I really don't know what to expect.
I had stereo optical microscopes at that time so that was about
the limit of my ability to see what was going on.

While I can't guarantee riches, I can certainly guarantee we'll learn
some strange new stuff about silver and metal displacement reactions.
I did literature reviews on this stuff in the late 80's and really
very little had been studied at that time. Now perhaps there is greater
interest due to the explosion in funding for nanotech research. All
the better reason to look at this system again. A forest of tiny
field emission emitters has to have some nanotech value, eh?

K.

-----Original Message-----
From: newcandle-bounces at ipdiscover.com
[mailto:newcandle-bounces at ipdiscover.com]On Behalf Of Nick Reiter
Sent: Sunday, September 07, 2008 9:38 AM
To: New energy for the new world.
Subject: Re: [NewCandle] Silver dendrites


Hi Keith and all,

Nice pic!  One wonders if highly dendritic growth
might be more influenced by vacuum fluctuation energy
than orderly epitaxial growth.  Conversely, highly
dendritic structures might form an exotic fractal
antenna for vacuum radiation modes?!?!

A few years back, I was trying some nutty
electrodeposition of tellurium (Te) and got similar
dendrite forms.

n


--- Keith Nagel <NewCandleAdmin at ipdiscover.com> wrote:

> Hi All,
>
> Here's a photo of an experiment I did around the
> time of my work with
> silver.
> The cathode shown here is carbon, the anode a silver
> disc (not shown) below,
> the electrolyte is a solution of silver nitrate.
> Applied current was in the
> neighborhood of a hundred milliamps.
>
>
http://www.kpnconsulting.com/newcandle/download/SilverDendrite.jpg
>
> Silver is interesting in that it really wants to
> grow in the dendritic form,
> it requires a special chemistry to get a solid dense
> plate at reasonable
> current densities.
>
> The point of this study was to better understand
> dendritic growth of silver
> under controlled current density. In the aluminum
> displacement reaction,
> the current density is uncontrolled but in general
> is _very_ high.
>
> K.
>
>
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>
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>


The Holy Grail 'neath ancient Roslin waits.
The blade and chalice guarding o'er Her gates.
Adorned in the masters' loving art, She lies;
She rests at last beneath the starry skies.




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