In a message dated 6/29/00 8:46:46 AM EST, [email protected] writes: << Subj: CS>Polarity Switching & Stirring Date: 6/29/00 8:46:46 AM EST From: [email protected] (Steve Young) Reply-to: [email protected] To: [email protected] (Silver List) Hi list, I did some experiments with DC polarity switching which are interesting. I use a constant current supply of 1.67 ma into #12 silver electrodes 3.9" of weatted length spaced 1.25 inches apart. "Brewing" time is two hours starting with 1.6 uS DW, no additives. I can start drawing 1.67 ma immediately as the generator can keep a constant current up to several hundred volts. Typical starting voltage is about 140, which drops over the two hours to around 12 volts or so as the conductivity increases. The control batch (no polarity switching) ended up measuring 16.2 uS. Switching polarity every 17 seconds produced 7.8 uS. Likewise, switching polarity every minute produced 7.8 uS. The polarity switching does indeed keep electrode sludge buildup low, but at a cost of reducing the strength by about 48% for a given run time. Question - why the dramatic reduction in strength from polarity switching, when all other conditions are the same? It is interesting to monitor the voltage drop across the electrodes during polarity switching. At the moment of switching, the voltage drops for a second, then rises above the nominal state value for 8 - 10 seconds, then returns to nominal. Must be some interesting dynamic electrochemical "readjusting" going on when the polarity shifts.
Steve: Since you are reversing polarity, the electrochemical reactions are reversed. Previous to switching polarity, the boundary layer at the anode/electrolyte interface had a surplus of charged silver particles, and the boundary layer at the cathode/electrolyte boundary had a deficit of charged silver particles. (Thinking of this electrolysis as an electron pump at the electrodes may help understand what I'm saying.) The migration of these charged particles across either the cathode or anode, electrolyte boundary layer generally constitutes the rate limiting step for the corresponding electrochemical reactions. My guess is that the migration of oxidized silver away from the anode/electrolyte boundary layer constitutes the overall rate limiting step since that's where the whole process begins and initially it's very slow. When the polarity is reversed, you now have a silver ion (I'm using the 'Ivan approved' definition of 'ion' here) surplus where you had a deficit, and a silver ion deficit where you had a surplus, forcing your current controlled system to significantly lower voltage (while excess supplies or deficits last, i.e., while unsteady state conditions remain) to maintain constant current set by your controller. After that, it probably overshoots voltage a bit on its way towards reestablishing steady state. Roger -- The silver-list is a moderated forum for discussion of colloidal silver. To join or quit silver-list or silver-digest send an e-mail message to: [email protected] -or- [email protected] with the word subscribe or unsubscribe in the SUBJECT line. To post, address your message to: [email protected] Silver-list archive: http://escribe.com/health/thesilverlist/index.html List maintainer: Mike Devour <[email protected]>
