gandolf:
The left most container is precipitated silver oxide crystals, and is why I don't use pulse width modulation.
Cool! Thanks for knowing what it is!
Colloidal Silver Oxide Generation!
In case anyone wonders why I don't drink the stuff I make!
Ag2O is nasty stuff and I only do this for fun. Never try to make colloidal silver like I make stuff!
http://www.sciencelab.com/msds.php?msdsId=9924938I do it for entertainment only!
Sun 12 Mar 2017 03:52:08 AM MDT
Once you play with it, and note it's rather distinctive color, I must admit that some PWM based colloidal silver maker units might be making this Ag2O stuff in excess. And the bare battery units at first or when the batteries go dead. (NOT trying to get into a P****** contest there...).
Taking good and true pictures of colloidal silver is sort of hard.... Maybe our photography friends could tell use how to do it right?
From your data, during the ON time, you are pushing 20mA through the electrodes, with a very short duty cycle. The result is that you produced a lot of silver oxide in a short amount of time, and then turned off the electrode voltage for the rest of the cycle, removing the electric field which purges the silver ions from the diffusion layer. This exceeds the solubility limit of the silver oxide, in the diffusion layer so it precipitates out as silver oxide.
My 'play system' of the moment free floats the current during the off cycle rather than forcing the cell voltage back to zero volts. Thus I can "see" the anode field voltages
And here they are:
There is about a 300uV offset voltage too which I do not yet understand but the data below is corrected for that...
Maybe old electrode offset voltage since they have been through a lot... But it seems pretty strong. Ag2O voltage??
20V drive. Free float on off cycle. Glucose in.
mA V Anode %duty Resistance
0.5 0.100 2.38 952
1 0.200 4.76 952
2 0.400 9.52 952
2.5 1.500 15.80 ?
3 1.500 21.05 1053
4 1.550 21.05 1053
5 1.600 26.32 1053
6 1.600 31.58 1053
7 1.650 36.84 1053
8 1.700 42.11 1053
9 1.700 47.37 1053
10 1.700 52.63 1053
I believe a pulse width modulation system could be made to work with the addition of 2 more electrodes. The additional electrodes would be placed on the outside of the flask to provide a constant electric field during the OFF time of the cycle which would aid the movement of the ions out of the diffusion layer. This though is just not worth the trouble, so I haven't tried it.
Been there, done that!!!!
I don't tell you guys everything.
I was hoping the bury this experiment under the rug but....
The problem is the glass insulator allows zero current flow or effects in the conductive liquid... Electrostatic fields are no match for conductive field currents. In my experiment I was using AC current and capacitance to get displacement currents across the insulators (like capacitors do) and offset them to produce a
net DC voltage using a glass coated cathode. My problem is I did not have enough frequency or voltage to force significant AC displacement currents past the glass insulators to set up the DC fields in the liquid. Now, I CAN do that, but I put this one off for a latter day rather than pulling out those 220VAC cables and big RF power supplies... An experiment for a later day
Having a glass cathode would just be awesome even if it does require the most messy complex colloidal silver system ever made
But our low currents are in range of such systems....
Update: I retested and fixed the above data chart. The voltages did turn out to be just what we would expect. Below 0.8 volts you are just making silver oxide as kaphra explained.
BTW - The cell resistance change is almost exactly centered at 0.8 volts on the anode. That is exactly the standard electrode potential for silver. So science does work!
But you don't want the delta free float potential to go less that 0.8V or you are just making colloidal silver oxide which is just a skin irritant...