[NewCandle] Silver dendrites

[Nick Reiter]

Hi Keith,

Sample prep for SEM, at least for samples like this
that wouldn't have to be gold-sputtered or
micro-polished, is not rough per se, but for delicate
dendrites, oy, hard to tell.  Can they even be removed
from the solution environment without them falling
into a pile of tiny crystals?

I'd be willing to give anything a try.

I don't have any of my old original anode glow
aluminum samples, be it strips or pop can bottoms, but
t'aint hard to re-make a couple variants.  I'm itching
to see how the oxide forest that produces the fierce
yellow glow of the phosphoric acid immersed surface
differs from the topography of say the mild bluish
glow oxalic acid emitters.

hi ho silver away...

n

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

> 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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> >
> 
> 
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> 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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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.