>From an old post of mine. I'll just leave it all in and give credit where credit is due...
When I started looking into how to make CS one of the main problems I encountered was how to customize my setup for the materials I might have access to, how to tell when the CS was done, and what concentration it was. As a starting point Bob Lee, in his post of 4-11-98, gives a very valuable discussion of Faraday’s equation for electrolysis which indicates how much silver is freed from the electrode during electrolysis. Add to this Mike Monett’s experiments indicating that low voltage / very low current setups allow one to make CS with a single 9v battery and a series resistor, providing for nearly linear operation of the cell, and dispensing with the need for stirring. (Thanks Bob and Mike.) Also, perhaps it is more correct to call this EIS (electrically isolated silver) rather than CS (colloidal silver) since it is apparently much more ionic than colloidal. This post is not essentially different from one of Mike’s but is put in a form where I can more intuitively understand what is involved in the calculations. For our purposes, there are three formulas that apply to the calculation of this process. The other equations are merely conversion factors which convert from ounces to grams to mg to liters, etc. *How much silver is liberated during the reaction? 1. Faraday’s equation for electrolysis m = k*I*t where: m = mass in grams k = electrochemical equivalent = 0.001118 I = current in amps t = time in seconds This formula tells us exactly how much silver was liberated from the electrode (anode) and is determined by k = a constant, I = current, and t = time. [You can ignore this – just use the constant. “k”, the electrochemical equivalent, is derived from the chemical equivalent for silver which is the atomic weight in grams of silver divided by the valence number times the number of coulombs (ampseconds) required to liberate this amount of silver: k = atomic weight of silver / valence # * coulombs to liberate = 107.88/1*96500 = 107.88/96500 = 0.001118 This is from Bob Lee’s post of 4-11-98] Conversion factors: Sec = hrs*3600 ;convert hours to seconds I = ma/1000 ;convert milliamps to amps So, the variables for this equation are the amount of current and the time of the reaction. *What is the concentration of the liberated silver in the volume of distilled water? 2. ppm = mg/lt where: ppm = concentration of silver in parts per million mg = milligrams of liberated silver lt = liter of distilled water The concentration is determined by the amount of liberated silver (from equation #1) per volume of distilled water used. Conversion factors: mg = gm*1000 ;convert grams to milligrams ml = 29.57*oz ;convert ounces to milliliters lt = ml/1000 ;convert milliliters to liters The variables for this equation are the amount of liberated silver and the volume of distilled water used. *The current density at the electrodes (anode). 3. den = I/sqin where: den = current density in Amps per square inch of anode surface area I = current in Amps sqin = surface area of electrode (anode) in square inches Conversion factors: [for wire electrode] Sqin = pi*d*l ;surface area = pi*diameter of anode*length of anode d = .08081 in ;for 12 gage wire d = .06408 in ;for 14 gage wire [For 12 gage wire, 1 square inch = approximately 4 linear inches.] [For 14 gage wire, 1 square inch = approximately 5 linear inches.] The variables for current density are the surface area of the electrode (anode) and the current in Amps. You can have any length of electrode you want. For equation 1 and 2 it doesn’t matter. What does matter about the current density, as was shown by Mike Monett, is when the current density is very low, about .080ma/sqin then the process can be made nearly linear and there are apparently few losses of the liberated silver due to agglomeration or plating at the cathode. An additional benefit is that stirring is apparently not required. Also, current limiting can be accomplished by a simple series resistor of the correct value. *To calculate the correct resistor, Ohms law: [OK, here’s a fourth equation to calculate the needed series resistor ;-] 4. R = E/I ; Resistance in ohms = Voltage / Current Verify the current in circuit with a milliammeter or measure voltage across the resistor and calculate: I = E/R ;Current in Amps = Voltage / Resistance in ohms I would recommend that one calculate the maximum amount of current allowable for their electrodes for very low current CS where den = less than .08ma/sqin for example. Just don’t exceed that current for your setup. Special thanks to Bob Lee and Mike Monett. Dan On Tue, Oct 13, 2009 at 1:35 PM, Jonathan <john_smith...@yahoo.com> wrote: > > > *Does making CS basically just boil down to electrolysis? I see systems > with one 9 volt that make 3-5 ppms in about 2-1/2 hr.s. Then I see systems > that use four 9 volt batteries. And they make 10 ppm in about 1-1/2hr.s. I > would think then if the four 9 volt system put out less then 36 volts > because of lets say the batteries getting old. It would theatrically still > make good CS. But just take longer because of the lower voltage? * > > >
