I notice the discussion of current regulation, electrode geometry etc. Here is my 2 cents worth. Every one is correct in this discussion as far as they go. All generators work in exactly the same manner, that is sintering silver atoms from the anode (positive electrode), and all produce perfectly good CS within certain boundaries and limits.
The difference in generators is really in the ease of use and the concentration they are able to produce. The simple 3 or 4 battery method has the advantage of short generation time, but requires constant attention (stirring, electrode wiping etc.). these generators produce fine CS in the 5 to 10 ppm range. The conductivity of the water past this range allows too high a current flow, and that coupled with a quite high voltage causes a high particle mobility. The consequence of this is that many particles contact the cathode (negative electrode) and are reduced to the residue or treeing we see. This residue enevitably finds its way into the solution which results in the cloudy, dark and unstable colloid we see many questions about. Hot water limits these factors to some extent, mainly by the convection currents in the water mixing the silver plume through out the solution. Constant current (current limiting) generators over come many of the problems described above by limiting the current to a value, where the number of particles coming off the anode is not so great that they cannot be spread throughout the solution before they meet the cathode. As the resistance in the solution falls (with the introduction of silver particles) in this type of generator, the voltage drops and therefore so does the particle mobility. This is a most beneficial set of circumstances. The more particles there are in the water, the less energy they have in movement, and the less likely they are to be reduced at the cathode and the less energy do they have to overcome electrostatic repulsion when they encounter each other. As long as the voltage stays above about 1V the generator will continue to disassociate silver ions from the anode. These generators can produce clear or light yellow colloid to high concentration (10 ppm +), but are more technical and expensive to implement, and require more time to generate a given concentration. The pulsed generators and polarity switching generators can be thought of as current limiting hybrids and seem to exhibit many of their positives and negatives. Low voltage generators (9 to 15volt) are very simple to implement and also display the positives of current limit devices, due to the slow manner in which they dissasociate the anode into the water, but above a certain point they behave like the higher voltage units. Good up to about 15ppm. Long generating time. Electrode configuration and crossection affect CS generation only in as much as they have an influence on the maximum current draw, and the distance the silver ions have to travel before they meet the cathode. An arrangement that is constant in geometry will have reproducable results. Particle size is a much discussed and overly emphasised part of CS generation. Particle size, as determined by colour, is effective from clear through yellow-green, yellow and gold. The range is apparently <1nm to 15nm (<.001micron to .015micron) and, as you can see, the difference is slight. All exhibit very good stability and antimicrobial proterties. Ivan -- 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] List maintainer: Mike Devour <[email protected]>
