Marshall wrote: > > Although you are correct that his statement is incorrect, he is not > talking about the tyndall, which is scattering of light, but rather the > color, which is the complement of the absorption spectrum of the > particles. They are independent of each other, except both do vary with > particle size. > > Marshall
Color does vary with particle size, but it also varies with particle dispersion which is a function of zetapotential. This effect is only apparent when dealing with colloids having a high concentration of very small (nanometer sized) particles. We first noticed it with Mesosilver. The normal light absorption of Mesosilver is at 400 nm which gives it the characteristic brownish (ice tea color). The dispersion properties could be altered by miniscule additions of ionic contaminants (in the ppb range) and the color absorption wavelength would vary over a range of several hundred nanometers which will make a pronounced change in the apparent color. The particle size and concentration remained constant through out these wide variations in color. The only thing that changed was the dispersion which is related to small changes in zetapotential caused by the ionic alteration. frank key www.colloidalsciencelab.com -- 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]>
