Author Topic: 3) Electrolytes and Reducing Agents  (Read 15388 times)

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Offline kephra

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3) Electrolytes and Reducing Agents
« on: November 03, 2012, 08:58:43 AM »
Electrolytes and Reducing Agents
Copyright © 2011  W. G. Peters


The electrolytic process for making colloidal silver requires an electrolyte to work.  Even pure distilled water with nothing added to it acts as a weak electrolyte because a very small amount of pure water disassociates into H+ and OH- ions.   You might say that a certain amount of water dissolves in itself as hydrogen hydroxide.  A liter of pure water will contain 10-7 moles1  of hydrogen ions, and 10-7 moles of hydroxide ions.  This amounts to 0.0017 milligrams of hydroxide ions, but this tiny amount is enough to make silver hydroxide when you put silver electrodes in the water and connect them to a battery.  These hydrogen ions and hydroxide ions are the current carriers which allows current flow through the electrolysis cell, but so few carriers result in a very weak current.  A weak current results in a long process time.

Aside from the long process time, using the hydroxide inherent in pure water as the electrolyte has another problem.  The amount of hydroxide is not constant, but increases as the amount of silver hydroxide increases.  This creates a run-away process that gets faster with time, and therefore is difficult to control as anyone who has used this simple process can attest.

We can solve these problems by adding an appropriate electrolyte to our water.  A useable electrolyte must have certain characteristics.  It must be non-toxic above all else.  It must not form any toxic byproducts.  It must form a soluble compound with the silver anode.  It should be safe to handle. It must dissociate in water (ionize). Its positive ion should not plate out onto the cathode.  It should be inexpensive, and readily available.  These requirements reduce the number of choices considerably.

In choosing the specific compound to use, toxicity is paramount.  Luckily substances normally found in human physiology are good candidates.  Chlorides, citrates, gluconates and hydroxides and carbonates are all non-toxic anions3 especially in the low concentrations we need.  Chlorides are everywhere in the body, and citrates are an integral part of the citric acid cycle which provides our energy.  Gluconates are commonly found in foods.  Hydroxide is a natural constituent of water.   The body is very adept at handling these substances.

There are only two very common bio-compatible substances which will inhibit plateout onto a cathode.  They are sodium and potassium.  Both of these ions react strongly with water as soon as they are reduced to metal at the cathode, and create hydroxides which are water soluble.  So, the sodium or potassium stays in solution as ions.  Because of this, a sodium or potassium compound would be ideal for making colloidal silver electrolytically.  An added benefit of using sodium compounds is that it is self replenishing.  The sodium ions that contact the cathode are immediately reduced to sodium metal, and then react with the water to become sodium hydroxide.    The net result is that the electrolyte is never used up.

For these reasons, a very good choice of an electrolyte is sodium carbonate, commonly known as washing soda.  It is cheap, readily available, and it works extremely well for making colloidal silver.  It is also safe to handle.  Everyone has consumed sodium carbonate, it is what results from heating baking soda, so is a common ingredient in baked goods.  Sodium carbonate is the salt of a strong base and a weak acid.  When dissolved in water, it creates sodium hydroxide and carbonic acid.  Very little of the the carbonic acid actually ionizes, and exists as carbon dioxide dissolved in the water.... like soft drink.  The net result is that the sodium carbonate liberates mostly sodium and hydroxide ions., not carbonate ions.

While baking soda could be used, it is not nearly as good because it produces only half as much sodium hydroxide and also produces more carbonic acid.  However, it is very easy to convert baking soda to sodium carbonate (aka washing soda) simply by baking it.  When baked, baking soda gives off carbon dioxide gas and water vapor which is what makes baked goods rise.

When using sodium carbonate as an electrolyte, the MINIMUM theoretical voltage needed is 3.5 volts.  Below this there is not enough voltage to reduce the sodium at the cathode and oxidize the silver at the anode.  This comes from the electrochemical series which describes the voltage a metal creates when used with a different metal in an electrolytic cell (battery).  Experiments I have conducted seem to confirm this.  The sodium ion requires -2.71 volts to force an electron to it, and the silver atom requires 0.8 volts to remove an electron from it.  So the total is 3.51 volts.   In practice, the voltage should be several times this minimum because there is voltage lost in the bulk water itself.  10 volts is a good minimum across the electrodes producing satisfactory results, but I have found that higher voltage is always better. However, the improvement is not linear.  IE: 10 times the voltage does not provide a ten fold increase in quality or efficiency.  Anything over 20 volts is probably not very beneficial with an electrode distance of 1.5 inches.  Wider spacings or different electrode geometries will require higher voltage for the same result.   

Using sufficient sodium based electrolyte keeps most of the silver from plating onto the cathode.  The positive ion with the lowest redox potential from the electrochemical series will selectively plate out.  Since sodium's redox potential is -2.71 and silvers is +0.8, the sodium ions keep the silver from plating onto the cathode.  There is a correct amount of sodium carbonate which also produces the optimum pH (8.5) of the water.  This amount is 106 milligrams of sodium carbonate per liter of water.

Reducing Agents:

Reducing agents are necessary if one wishes to make non-ionic colloidal silver.  While heat alone can accomplish this, the process is slow, and not always complete.  Also, it is impossible to make higher ppm concentrations of silver using heat alone as the silver oxide exceeds its solubility and precipitates out before heat reduction occurs.

As with electrolytes, the non-toxicity of a reducing agent is the first consideration.  I pondered this for a long time until I realized that any food we eat will undergo chemical oxidation by the body.  The body knows quite well how to handle the oxidized byproducts of metabolism.   This means that if the food is non-toxic, so will be its reduction/oxidation products.  Luckily, there are many sugar based and other food products which are reducing agents and work with silver.  The quality of the product differs with choice of reducing agents in that some produce more consistent particle sizes, some work faster, and some produce more stable product. Agents which have shown to work are glucose, corn syrup, pure light honey, maltose, maltodextrin, and cinnamon extract.  Tea is also a reducing agent, and has been shown to reduce gold.  So far, one of the best ones I have found is clear corn syrup.  Corn syrup is a 50/50 mixture of glucose and maltose plus water.  Both glucose and maltose are reducing agents for silver.   Ordinary table sugar (sucrose) does not work, nor does ordinary starch.   

When the process is complete, and all of the silver ions are reduced, the solution will contain nothing toxic.

For any of these agents to work, the pH of the solution must be basic (above pH 7).  pH above 7 opens up the ring structure of a glucose molecule activating it as a reducing agent.  Using sodium carbonate as an electrolyte automatically raises the pH sufficiently to activate the reducing agent.   

One ml  of 1 Molar sodium carbonate per liter/quart is a very good amount to use, as it is sufficient to prevent plateout, sufficient to activate sugar based reducing agents, and provides plenty of conductivity.  Note that different size dropper tips will dispense more or less liquid, so you can calibrate your dropper by counting the number of drops required to fill a teaspoon with your electrolyte and divide that by 5.

1)   A mole of any substance contains approximately 6 x 1023 molecules, and weighs the sum of its atomic weights in grams.
2)   Coffenol developer contains Folgers instant coffee, vitamin C, and baking soda.
3)   Anions are  ions which are more negative than the anode.  Cations are ions which are more positive than the cathode.
4)   It gives the salt and vinegar flavor to certain brands of potato chips.

Colloidal Silver is only a bargain if you make it yourself.