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Topic: what is the chemistry of silver colloidal generators?  (Read 9167 times)

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Offline Ikati

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what is the chemistry of silver colloidal generators?
« on: December 27, 2008, 08:52:14 PM »
I was wondering if you could answer a chemistry question that I have asked, and not gotten very definitive answers.   

The subject is the making of collodial silver.  You will see different kinds of collodial silver makers all over the internet, but basically they all work with basically the same setup.

The basic setup is a container of distilled water (nothing else), and a 'device' that consists of a battery or some electrical source, and two electrodes.  Both electrodes are pure silver.  You put the silver electrodes into the water, turn on the current, and wait.  This creates a solution of "collodial silver", which is really supposed to be mostly ionic silver.  The resultant solution can be anywhere from 3ppm to 20ppm.

What I was wondering is what is the chemical equation for this process, and what exactly is produced.  Will the water contain anything but Ag+?  how does this work with just water, silver, and electricity?

I have looked around a lot, and everything i find talks about adding something to the water, but nothing about what happens in electrolysis with just distilled water and silver electrodes.

here is a very popular generator, the silvergen:
http://www.silvergen.com/technica.htm
http://www.silvergen.com/informat.htm

I did find this, but it is kind of vague:
http://www.silver-colloids.com/Papers/IonsAtoms&ChargedParticles.PDF

   Various forms of silver
   Colloidal silver is generally produced by electrolysis when an
   electric current is passed through a series circuit
   consisting of a silver electrode and de-ionized (DI) water. The
   current can be either alternating current (AC) or
   direct current (DC). The current flow causes Ag0 (metal) and Ag+
   (ions) to migrate from the electrode into the
   DI water. AC processes tend to be more efficient than DC in limiting
   the ionic concentration.

   It is generally assumed that water ionizes to H+ and OH-, and that the H+, in the
   form of the hydronium ion, H3O+, migrates to
   the cathode, where it is reduced to hydrogen gas, H 2, which is
   liberated. The electrons taken from the cathode
   are replaced at the anode when Ag metal goes into solution as Ag+.

   Therefore, colloidal silver consists of silver in two distinctly
   different forms, metallic silver particles and ions.
   The total amount of silver that is reported as the silver
   concentration (in parts per million) is the sum total of the
   silver contained in the particles and the silver contained in the
   silver ions.

I guess what i'm asking is what is created at the anode and at the cathode, and will you end up with any compounds as well as silver ions and silver colloids?  What are the equations for this particular process?

Thank you for any information you can give me to clear up this question.

Offline Arkcon

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Re: what is the chemistry of silver colloidal generators?
« Reply #1 on: December 27, 2008, 09:24:07 PM »
By definition, and I mean as defined in contemporary chemistry textbooks, not advertising blurbs, a metal colloid in water is a fine dispersion of metal particles, so small in size they don't settle out.  Faraday prepared colloidal dispersions of gold and platinum, in water, that as the story goes, haven't settled out to this day.  The bit about ions, if they are real, aren't part of the colloid.  I'd always assumed, the gold, platinum or even silver were oxidized at the anode, but spontaneously reduced, because these particular oxides aren't stable, but I never worked out the reducing agent, H+, maybe, or other trace impurities in the water?  Organics are quite good at reducing silver ions to free metal -- ask anyone who's spilled silver nitrate in themselves or any argyria sufferer.
Hey, I'm not judging.  I just like to shoot straight.  I'm a man of science.

Offline Ikati

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Re: what is the chemistry of silver colloidal generators?
« Reply #2 on: December 27, 2008, 10:09:22 PM »
Quote from: Ikati
This creates a solution of "collodial silver", which is really supposed to be mostly ionic silver.

yes, I realize that even though they call this solution colloidal silver, it is mostly ionic silver that is produced ..

but what would be happening at the anode and at the cathode when you have only Ag + H2O + current?  What exactly is happening at the anode and what is happening at the cathode?


Offline nj_bartel

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Re: what is the chemistry of silver colloidal generators?
« Reply #3 on: December 28, 2008, 12:01:41 AM »
Well, distilled water isn't conductive.

Offline Ikati

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Re: what is the chemistry of silver colloidal generators?
« Reply #4 on: December 28, 2008, 12:20:12 AM »
Well, distilled water isn't conductive.

not at first.. but once enough ions enter the water.. then it becomes conductive.

Offline nj_bartel

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Re: what is the chemistry of silver colloidal generators?
« Reply #5 on: December 28, 2008, 12:27:20 AM »
Ions coming from...?

Offline Ikati

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Re: what is the chemistry of silver colloidal generators?
« Reply #6 on: December 28, 2008, 12:40:35 AM »
from the silver electrode.

I've watched it...  nothing happens for a while.. then you can see particles forming on the negative electrode and the positive one gets a little black by the end of the process.

when you start, the ppm of the distilled water is less than 1, then when you finish, it is around 10ppm. 


Offline macman104

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Re: what is the chemistry of silver colloidal generators?
« Reply #7 on: December 28, 2008, 12:51:05 AM »
from the silver electrode.

I've watched it...  nothing happens for a while.. then you can see particles forming on the negative electrode and the positive one gets a little black by the end of the process.

when you start, the ppm of the distilled water is less than 1, then when you finish, it is around 10ppm. 


Black precipitate sounds like Ag(s) pellets.  Well, at the anode oxidation occurs, so maybe, can you generate Ag+, and then at the cathode take those Ag+ and reduce them back to Ag(s)?  Since the cathode is negatively charged, and the solution has Ag+ in it, you would expect them to migrate.  Just a thought.  If run for a long time, will the anode slowly shrink?  I wonder how long it would take...

Offline nj_bartel

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Re: what is the chemistry of silver colloidal generators?
« Reply #8 on: December 28, 2008, 01:23:26 AM »
Is your distilled water left to open air?  You're probably forming a carbonic acid electrolyte.  If you're forming Ag+, what's the counter ion?  The only thing I can think of is AgOH, which spontaneously changes into Ag2O, which is insoluble in water.  Note: Ag2O is also dark brown/black.

Offline Ikati

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Re: what is the chemistry of silver colloidal generators?
« Reply #9 on: December 28, 2008, 02:24:23 AM »
from the silver electrode.

I've watched it...  nothing happens for a while.. then you can see particles forming on the negative electrode and the positive one gets a little black by the end of the process.

when you start, the ppm of the distilled water is less than 1, then when you finish, it is around 10ppm. 


Black precipitate sounds like Ag(s) pellets.  Well, at the anode oxidation occurs, so maybe, can you generate Ag+, and then at the cathode take those Ag+ and reduce them back to Ag(s)?  Since the cathode is negatively charged, and the solution has Ag+ in it, you would expect them to migrate.  Just a thought.  If run for a long time, will the anode slowly shrink?  I wonder how long it would take...

My friend has a silvergen generator that he has had for over a year.  Still uses the original silver electrodes.  So.. they last a while. 

Something is left in the water in this process.  According to the literature on these sites, it is silver ions.  If you measure the ppm with a meter, it starts out low (1 or less for distilled water), then goes up to anywhere from 5ppm to 20 ppm (depending on how long you run it.

You can see the Tyndell effect after you make it (by shining a laser light thru the solution).

What people want from these little gadgets is a solution with silver ions.  It acts is used to kill bacteria, and people use it for things like foot fungus, or sore throats.   

But.. I just wonder how it works.. like you said, if silver ions are being produced at one electrode... what is going on at the other electrode?  That's why I was wondering what the equations were for this process.

Offline Ikati

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Re: what is the chemistry of silver colloidal generators?
« Reply #10 on: December 28, 2008, 02:55:39 AM »
Is your distilled water left to open air?  You're probably forming a carbonic acid electrolyte.  If you're forming Ag+, what's the counter ion?  The only thing I can think of is AgOH, which spontaneously changes into Ag2O, which is insoluble in water.  Note: Ag2O is also dark brown/black.

The one I have screws onto any standard quart bell jar.  so.. you fill up the quart jar with distilled water.. but, yes, you leave some air in there.  You screw it on, plug it in, set the ppm you want the final solution to be, and turn it on. 

In this one, they have a stirrer, so the water is moving, and the particles don't agglomerate (well, not that much).  But some of these generators don't have the stirrer.

the particles that collect on the negative anode are gray.  But when I wipe the anodes after the process, the positive one is darker (like tarnished silver?).  But.. maybe I didn't remember the color correctly.  Maybe I'll make some more and note the exact color.

here is a video with the process... zip past the hype to where they actually show the electrolysis.
silver solution generator

but, there are a lot of videos out there showing these generators or how to build your own.

Online Borek

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Re: what is the chemistry of silver colloidal generators?
« Reply #11 on: December 28, 2008, 05:20:35 AM »
Well, distilled water isn't conductive.

not at first.. but once enough ions enter the water.. then it becomes conductive.

When it starts to be conductive it is no longer distilled :)
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Offline Ikati

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Re: what is the chemistry of silver colloidal generators?
« Reply #12 on: December 28, 2008, 05:39:41 AM »
Well, distilled water isn't conductive.

not at first.. but once enough ions enter the water.. then it becomes conductive.

When it starts to be conductive it is no longer distilled :)

 ;D  very true!

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