On 16 Jul 98 at 1:13, Doug wrote: > What I think we are seeing with the "black cloud" that gets > generated between the electrodes is silver oxide. The positively > charged silver particles react with the negatively charged oxygen. > This is the same stuff that builds up on fine silverware over time.
Actually the tarnish picked up by silver items over time is supposed to be silver sulfide. It just picks up the traces of sulfur floating around in the atmosphere. > I think it's also why one electrode gets a thick black film over > it. Yes, the positive electrode forms a black film which could be from two things: The substance forming there is indeed black in color, or the surface texture at the microscopic level is so rough that it absorbs light as well as carbon black does. Since the stuff I wipe off that electrode stains the tissue black, I'll assume it's black stuff, or a combined effect of color and texture. > If this is is so (and I look to those more sophisticated in > chemistry than I for comment) then what we are producing may not > be "pure" colloidal silver. Assume the formation of silver oxide on the positive electrode. Will silver particles or ions still be liberated there? The sputtering process works because electron bombardment "damages" the surface and causes individual atoms to be dislodged. It's transfer of kinetic energy from the electrons that overcomes the atomic forces holding the metal lattice and oxide molecules together. Being attached to the electrically charged (+) electrode to begin with, anything that gets thrown off tends to carry a positive charge, it's electrons being happier sucked away toward the positive terminal of the battery. <g> Once away from the metal, the positively charged atom near a positively charged surface will now be repelled. So it think (waving hands wildly for effect) the silver atoms most likely to be driven away from the electrode carry a positive charge. If they lose their charge from a collision with some negatively charged species, like O- or Cl- you'd get a compound again. But in the bulk of the water the positive ions (and clumps of ions that we would call "particles") happily float around short at least an electron per atom, just like any other metal ion. The only other place they're likely to run into a bunch of electrons is near the negative electrode. There, you will notice, we get that fluffy grey "slime". Bruce, I think, has claimed that it is just uncharged silver particles that have been scarfed out of suspension. Now particles of silver are pretty big and heavy and will tend to float around, bumping into water molecules and pretty much staying put. So only those that come close to the negative wire will actually stick there. Now are there compounds formed at the surface of the particles? Sure! Nothing is going to be pure in such a complicated environment. So there'll be some oxide and chloride and hydroxide and whatever else happens along. But the levels are not going to be high as long as silver is far more abundant than anything else in the water. > If this analysis is correct, then it may be worthwhile > investigating a way to rapidly bind the ionic oxygen that is > generated during the CS production thus reducing the presence of > silver compounds in the resulting liquid. Interesting thought. I hope we don't really have to go there, though. I imagine it could get pretty complicated. <grin> The only other issue I should mention is that the situation is a bit different if you use salt or something to speed things up. Particles are generated much faster and there's no time for the negative wire to get coated. We don't yet know what effect this all has on particle size, or what other compounds might get formed in there with the sodium and chlorine (or bicarbonate) floating around. Anyway, that's my picture of what's going on. I don't claim authority for it, as I'm not a chemist or a physicist, but I do have some experience with sputtering, e-beam and thermal evaporation, and a few plasma enhanced gimmicks for depositing metals and metal compounds in near vacuum. Many of the concepts work here. Be well, Mike D. [Mike Devour, Citizen, Patriot, Libertarian] [[email protected] ] [Speaking only for myself... ] -- 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]>
