Bob wrote:
> It cost $75.00 to have a particle size TEM made and I know of no one > that has done that except me. When I reported the use of a wide anode 2 > 1/4" x 5 1/2" with a #14 wire cathode running with a constant current > regulator, which does not cut in until that levelof current is reached. > (check my web site www.hvacsilver.com to see data chart for such a run) > > I had a TEM made for that and it is sub-nm to 24 nmin size. > > The limited current on the referenced sample was 12.67 ma. The answer to > you question,small current small size, is no. > > "Ole Bob" TEM myth.. TEM images of ionic silver solutions do not show the size of colloid particles present in the solution. What shows up in a TEM image is silver oxide particles formed when the water is removed to prepare a sample for TEM observation. Reproduced from the FAQ on www.silver-colloids.com What happens to the silver ions in solution when the water is evaporated? Silver ions in a solution cannot exist without water, so when the water is evaporated the silver ions (cations) must combine with an available anion to form a compound. The predominant anions present in a silver colloid solution are hydroxide and carbonate. The compounds thus formed are silver hydroxide and silver carbonate. Silver hydroxide is unstable and reduces to silver oxide and hydrogen. The silver carbonate will reduce to silver oxide and carbon dioxide. The final compound that remains is silver oxide. This process begins as a single silver ion is forced to combine with a single anion forming a single molecule of the compound. The molecule has no ionic charge and therefore no repulsive force. The lack of repulsion causes the molecules to be attracted to each other by van der Waals' force of attraction which causes them to aggregate and form small particles of the compound. The size of the particle growth is limited by the reduced mobility of the molecules as the water evaporates. What remains is particles of silver oxide whose diameter is 1 - 3 nanometers. It is these particles which predominate in TEM images made of silver colloid solutions which have a high ionic content. Reproduced from: http://www.silver-colloids.com/Papers/definitions.html#TEM transmission electron microscopy (TEM) - A form of microscope that uses a beam of electrons instead of a beam of light (as in an optical microscope) to form a large image of a very small object. In optical microscopes the resolution is limited by the wavelength of the light. High-energy electrons, however, can be associated with a considerably shorter wavelength than light; for example, electrons accelerated to an energy of 105 electronvolts have a wavelength of 0.004 nanometers enabling a resolution of 0.2 - 0.5 nm to be achieved. The transmission electron microscope has an electron beam, sharply focused by electron lenses, passing through a very thin specimen onto a fluorescent screen, where a visual image is formed. This image can be photographed. When used to observe colloidal silver solutions, the sample must be desiccated to remove the water. This removal of water forces the silver ions in solution to combine with anions in solution to form silver compounds. This dramatically changes what was in solution so that what is observed using the TEM now has little relationship to what was in the solution before desiccation. For this reason, the interpretation of TEM images of ionic solutions becomes difficult in the extreme. The TEM is sometimes used in an attempt to measure the size of particles in solution. The U.S. National Bureau of Standards (now N.I.S.T) has determined that it would required at least 10,000 TEM images be analyzed in order to make a statistically valid measurement of particle size based on TEM images. For this reason, the TEM is not considered viable for measuring particle sizes. frank key -- The silver-list is a moderated forum for discussion of colloidal silver. Instructions for unsubscribing may be found at: http://silverlist.org To post, address your message to: [email protected] Silver-list archive: http://escribe.com/health/thesilverlist/index.html List maintainer: Mike Devour <[email protected]>
