Author Topic: How much is too much reducing agent  (Read 27742 times)

Offline kephra

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How much is too much reducing agent
« on: October 30, 2014, 04:15:45 PM »
I have always had excellent results with colloidal silver that I reduced with Cinn Extract (crystal clear & nice color). I have struggled until just recently with sugar reduced though. It was inconsistent. Sometimes good sometimes just fair and sometimes (long time ago) almost as bad as your last pic. It wasn't until I drastically diluted the Karo & reduced hot with only a drop or 2 of dilute Karo that I started getting some consistently great results.

Rick, an excess of corn syrup does not make any difference.  It will not make your solution turbid or extra dark unless you have a lot more silver in the water than you think.

This morning, I made 1 quart of 20 ppm ionic silver, put 1/2 in each of two bottles.  I added 2 drops of dilute corn syrup to bottle A, and 20 drops to bottle B.  Both bottles heated in my microwave for 2 minutes and 30 seconds.



So, Rick you have something else wrong.  The only thing excess glucose should do is make it slightly sweet.  Perhaps your current isn't what you think, as its the silver content that makes a difference in how dark it gets. 

« Last Edit: April 11, 2016, 01:22:03 PM by kephra »
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Bizill

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Re: How much is too much reducing agent
« Reply #1 on: October 30, 2014, 09:52:53 PM »
Thanks for this.  I was wondering just this but was afraid to ask and didn't want to further experiment just yet.

Offline RickinWI

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Re: How much is too much reducing agent
« Reply #2 on: October 30, 2014, 10:17:05 PM »
Hmmm, that is strange. Different results than I would have had. Next batch I make I will do the same thing & take pics.

Both A & B are very nice looking, but if I look very closely it seems that A might be a little more crystal clear than B ?   Or it could just be the angle.

My setup uses a 10 mA regulator. My last batch (2.5 L) ran @ 9.8 mA for 75 minutes so should be between 19 - 19.5 PPM. I get very little plate out on cathode. I have 3 multi-meters  and I switch them around occasionally to double-check them. The better of the 3 meters is the one I usually keep in series to measure mA. (The other 2 are Harbor Freight cheap ones but they all 3 read about the same) I use one of those to watch the voltage.

Will try to attach a pic I just took of the above mentioned batch.
I did my wine glass test on this batch to make sure it was fully reduced.

So many VARIABLES & so little TIME.

Offline Gene

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Re: How much is too much reducing agent
« Reply #3 on: October 30, 2014, 11:03:04 PM »
Just splitting hairs here but 75 minutes, 9.8ma, 2500ml is 19.6PPM.

I agree with Kephra.  Its not the corn syrup unless there's something horribly wrong with the bottle of it you have but that stuff keeps easily 10 years (I had one that got lost in the back of the pantry go DARK on me - like a dark beer color and yeah, I tossed it but it had to be back there 15 years, easy, maybe longer).

Its not your run time nor your calculations as they all look dead on.

The only other two parameters are the amount of water (which I'm sure you measured accurately) and the amount of electrolyte.

Water PH varies (yeah, even distilled and maybe over a 1-2PH range too).  If you don't have enough electrolyte in it where your PH is low and you come up under 7PH at the end of the run, the sugar really can't do its reduction job properly.  The solution needs to be at least slightly alkaline for that to happen properly.

Why not try this. Next batch, once you're done making the ionic, decant off a couple hundred ml of it into a separate jar and figure out how much extra sodium carbonate electrolyte to add to bring the total up to 20 drops per liter (1M solution) equivalent and try reducing that with the prescribed amount of corn syrup.

Heat it to just hot enough you can't really touch the jar and hold it for more than  second or two and then just leave it go.  For me by this point its already well on its way to straw color and the conversion completes in a couple minutes on its own.  No real reason or need to boil it and as Kephra says, the conversion will go more slowly if you only get the solution warm where it could take a couple hours to complete where you get a tighter particle size distribution for doing so BUT lets do it in a way the conversion happens more quickly so you can see it progress.  At the temp I suggest, it should be all over in less than 5 minutes for sure.

And let us know what happens if you choose to try this.

Its going to be something simple thats wrong.  Always is.  What its rarely though, is obvious.



Offline RickinWI

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Re: How much is too much reducing agent
« Reply #4 on: October 30, 2014, 11:26:33 PM »
I was thinking that different water pH might be the reason for differing results.

Good suggestion, I will try doing the test you mentioned next batch & report back.
So many VARIABLES & so little TIME.

Offline kephra

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Re: How much is too much reducing agent
« Reply #5 on: October 30, 2014, 11:32:20 PM »
pH makes a difference in how well the glucose works, but it will not account for batches that turn out too dark.  There are only two things that make it too dark:  Higher than normal amount of silver in the water, and contaminants.

Occasionally,  I run out of colloidal silver for my dog, and I use some of my RO water which reads about 16 TDS.  The colloidal silver made with the RO water is twice as dark once reduced.  I have no idea what is in my well water, but at 16 TDS, the contaminants are on the same order of magnitude as the silver.  Only silver has a yellow plasmon resonance though, so the darkening is caused by the contaminants.  I still use it for the dog though.
 
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Offline RickinWI

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Re: How much is too much reducing agent
« Reply #6 on: October 30, 2014, 11:35:07 PM »
Just splitting hairs here but 75 minutes, 9.8ma, 2500ml is 19.6PPM.


I was figuring about 0.1 -- 0.5 PPM lost to plate out.
So many VARIABLES & so little TIME.

Offline Gene

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Re: How much is too much reducing agent
« Reply #7 on: October 31, 2014, 01:30:42 AM »
You are being careful about not "tweaking" the electrolyte balance, stirring, waiting for things to stabilize while you have the cell running, aren't you?

If thats going to take more than a couple minutes to do, you'd be best to shut the current limiter off or at least unclip one of the leads from the cell during the period you're adding electrolyte, stirring, waiting for things to settle so you get a good reading and then clipping back on and taking a voltage reading and if its not right, unclip and do it again.  If you're managing to get 10 minutes too long run time for futzing with the cell, thats an issue.  But given where you're at, though that might push you close to or over the wire a bit by a hair (maybe 23PPM?) it sure doesn't sound like enough to account for the darker color.

Try a different brand of distilled water?

And you're sure your silver anode is at least 999 purity bullion?


Offline RickinWI

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Re: How much is too much reducing agent
« Reply #8 on: October 31, 2014, 05:05:36 AM »
When I start the electrolysis I do not start timer until I get enough electrolyte to get up to about 50% of target, but that only takes a couple minutes. Then I start timer & within another couple minutes I am up to target mA so it should average out about right. After that I do not stop the count-up timer unless I unclip a lead. I can be almost certain that I am not over 20 PPM.

I used to be good about testing each new bottle of DW, but after 30 or 40 of them came up with a 000 on my TDS meter I dropped that procedure. I guess I should start doing that again though just to be certain. Meter is OK cuz my Culligan water comes up 001 or 002 and my city tap water always reads between 145 --- 155 PPM. Since my batches are usually 2.5 L or 3.0 L I use a new bottle for each batch. Use remainder of bottle for rinse water & other things.
I am very thorough when cleaning my electrolysis beaker but I usually only do that after 3 or 4 batches. Remainder of time I just rinse it with DW after use & before next use. (Do I need to thoroughly wash after each run?) I wouldn't think so. I put the IS into different beakers for reducting so electrolysis beaker & magnet are only used for that.
Probably about 95% of my batches have been same brand of DW.
Next time I go to store I think I might try a different brand of DW since it could come up 000 PPM TDS, but have a different pH.

Fire off anode to an orange glow before each run. Anode is made of Canadian Maples (.9999) & .9999 Ag wire.
So many VARIABLES & so little TIME.

Offline cfnisbet

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Re: How much is too much reducing agent
« Reply #9 on: October 31, 2014, 08:14:43 AM »
The only thing I have seen that makes a difference with turbidity, is the pH of the DW after adding electrolyte, and then only with glucose-assisted reduction.

If there is not enough electrolyte in the solution, then when the glucose is added, the colloidal silver will go turbid. See the experiment on my blogpost:

http://blog.cgcsforum.org/?p=287

The amount of electrolyte is far less important (except in that you need it to allow accurate calculations of Silver ppm, and also to make my 7-litre colloidal silver batches complete before I die of boredom) if heat or cinnamon are used to reduce the silver.

I add the tiniest smear of syrup, but the electrolyte needs to be as given in Kephra's recipes in the Articles section. You know you have enough electrolyte when the Constant Current hold just kicks in and the current does not significantly alter during the electrolysis run.

Offline kephra

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Re: How much is too much reducing agent
« Reply #10 on: October 31, 2014, 01:54:14 PM »
The actual amount of glucose/fructose needed is very small. 
The chemical reactions involved are:
On the electrode:
Ag - e -> Ag+    (Silver is oxidized by the electrical voltage)
Ag+ + OH- --> AgOH  (Silver hydroxide created by electrolysis)
2AgOH  --> Ag2O + H2O    (Silver hydroxide decomposes to Silver Oxide.. this is ionic silver)
Adding glucose
Ag2O + C6H12O6 --> 2Ag + C5H12O5  +CO2(Free silver + sugar alcohol + carbon dioxide)

So, 1 molecule of glucose reduces 2 silver ions to silver metal.

From this, you need one molecule of sugar for every 2 silver ions.  A sugar molecule weighs 180 compared to silver which weighs 107 daltons.  So the actual amount you need is 180/107 times the weight of silver/2 in the solution. 

For 1 liter of 20 ppm silver colloid ( 20mg silver) the amount of glucose is a mere 17 milligrams.  This is less than 1 drop of Karo corn syrup.  Once this amount of glucose has reacted with the available silver, no more chemical reaction can or will occur.  The remaining glucose does nothing chemically. 

However, it is a random event which determines when the chemical reaction between the silver and glucose occurs.  Having more glucose increases the probability that a glucose molecule and a silver molecule will meet up and react in any given time period.  With more glucose, the reaction will increase in speed.  Heat also speeds up the reaction because heat increases brownian motion, and the molecules in motion are more likely to meet than if they are stationary. 

Insufficient electrolyte causes two problems.  The pH may be too low to activate the glucose.  At low pH, glucose molecules become ring structures where one end curls around to bond with the other end of the molecule.  This binds the active end making it unavailable to reduce a silver atom.  At higher pH, the ring uncoils freeing the reducing end of the molecule.

The other problem with insufficient electrolyte is the plateout on the cathode.  This makes fine 'dust' of pure silver which will not dissolve and is too large to do anything except add to the turbidity.

Too much electrolyte also poses a problem in that it may raise the pH too high.  At pH 10 the solubility of silver hydroxide drastically decreases due to the common ion effect*.  This makes it more likely for the silver hydroxide to precipitate which again increases the turbidity. 

As I have said many times, making colloidal silver is a balancing act.

* The common ion effect happens when two or more compounds have an ion in common.  This decreases the solubility of each of the compounds.  For example consider an imaginary compound AB which was a solubility of 1 gram per liter, and a second compound AC which also has a solubility of 1 grams per liter.  The common ion is 'A'.  If you try to dissolve 1 gram of AB plus 1 gram of AC in a liter of water, less than 2 grams will dissolve because of the common ion 'A'.  Each specific ion itself has a maximum solubility.

Edited to fix equations --- Thanks Rick for spotting my error.
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Offline RickinWI

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Re: How much is too much reducing agent
« Reply #11 on: October 31, 2014, 03:49:52 PM »
So this is starting to make perfect sense now. As I mentioned I have not had any problems with turbidity lately. The one thing that changed a while ago is that now I am doing the electrolysis at a higher mA. Since I am now @ higher mA, more electrolyte is needed to get the current up into the target range. More electrolyte = higher pH. Higher pH means glucose & fructose rings easily broken & electrons readily available for reduction.

So before when the pH was too low, I would add more & more drops of reducer. Depending on the temp, it usually took 3 to 5 minutes and all of a sudden it would all reduce at once. The result was turbidity & darker color theoretically caused by larger particle sizes, caused by how quickly the reaction happened.

So it would seem that having all the conditions (temp & pH) correct for the reduction reaction to proceed slowly would be the key to making colloidal silver with the smallest particle size possible.

This would account for why different people can get drastically different results even though they are following the same procedures. Different DW = different pH. Also explains why my earlier problems were inconsistent. (some batches of DW that started out @ lower pH.)
So many VARIABLES & so little TIME.

Offline kephra

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Re: How much is too much reducing agent
« Reply #12 on: October 31, 2014, 04:17:15 PM »
One more thing which causes excess turbidity, is a cathode that is too large.  For the process to work correctly, the voltage difference between the bulk fluid and the cathode has to exceed 2.7 volts.  This voltage is dependent on current and surface area.  If the surface area of the cathode is too large, the voltage at the cathode will drop below the amount needed to reduce sodium, and the silver will plate out even though the total voltage across the cell seems adequate.  This is the reason for not using a stainless steel vessel to make colloidal silver.
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Offline RickinWI

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Re: How much is too much reducing agent
« Reply #13 on: November 02, 2014, 06:18:16 PM »
OK, so I made a batch of colloidal silver last night. ( Remember I had mentioned a couple times that I have not had a turbid or dark batch in quite a while. ) So I tried to make a turbid sub-batch with 400 ml for the sake of the experiment. (replicating Kephra's experiment @ the start of this thread.) So I reduced most of the batch like normal but in the 400ml that was for the experiment I put 10 times the amount of reducer (diluted Karo). To my surprise that sub-batch turned out EXACTALLY like the rest of the batch. No turbidity & no darker color.

I was also planning to do the experiment Gene suggested by adding extra electrolyte to a sub-batch to see if it improved, but at that point there was no need since my entire batch of IS had plenty of electrolyte (high enough pH) to avoid any problems.

Conclusions:

1. The method I had developed over the months of just adding a tiny (stoichiometric  :) ) amount of diluted Karo was nothing more than a "workaround" or a band aid for the real problem of pH too low (too acidic).

2. When I raised my mA (current) a number of months ago it caused me to need more electrolyte to get up into the target range. That change inadvertently solved my real problem of pH too low to allow for proper reduction with sugars (Karo, dextrose etc.) but I didn't realize it until just now.

     2A. Apparently colloidal silver reduced with Cinnamon extract is nowhere near as "fussy" about pH since I have never had any problem with that. Makes sense since whatever molecule does the reduction with Cinn Extract is already there & ready to go to work by donating electrons. Whereas, with dextrose/fructose the rings have to be broken before they can donate an electron.

3. The "rule of thumb" that I was using for how much electrolyte to use is just fine when I am running at a higher current ( > 10 mA ) but when I was at lower mA it caused me to put less electrolyte resulting in a pH that was too low because I was only adding just enough electrolyte to get the current up into the target range.

4. The reason I was having inconsistent problems with turbidity was probably due to variations of the starting pH of the DW.

Other observations along the way: Months ago when I was at a lower pH I noticed that when I was reducing with Karo the color change would happen very slowly or not at all for 3 to 7 minutes of stirring (depending on temp & amount of reducer). Then all of a sudden it would go from almost clear to dark & turbid all at once ( about 15 sec. or less?) Almost like once it was pushed over the cliff then a chain reaction of some sort would happen. It's hard for me to picture what was happening on a molecular level. Conversely, now that I am at a higher pH the color change happens relatively slowly & smoothly. Not all at once.

Verification of above Conclusions: Next batch I will put in about half as much electrolyte as I am currently using to make the IS. Then I will reduce a 400 ml sub-batch with Karo. Then I will do Gene's experiment of adding back the rest of the electrolyte I left out to the rest of the big batch of IS. Then reduce 400 ml of that. Should have an interesting pic to post. I can almost guarantee it will not look like Kephra's pic in the first post of this thread.

In my mind it is well worth the time to investigate this matter since darker and more turbid colloidal silver indicates larger particle size. It is generally recognized that smaller particles are more effective at killing bacteria & viruses. So being able to make colloidal silver that is 20PPM & fully reduced that is crystal clear and is as light a color as possible is my goal. 
So many VARIABLES & so little TIME.

Offline kephra

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Re: How much is too much reducing agent
« Reply #14 on: November 02, 2014, 06:42:30 PM »
It would be best to always use the same amount of electrolyte, and adjust the current by raising/lowering the cathode in the water, and even adjusting the anode if necessary for very low currents.
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