Ah, the question of colour never dies ;-) I can possibly be of help here, but let me say at the outset, that all CS within the accepted colour range (clear, through yellow-green, yellow and gold) exhibit very good antimicrobial properties.
The colour of a colloid is dependant on the particle size, and how that affects the reflection, refraction and extinction of visible light. The smaller the particle size the smaller the wavelength of light it will absorb leaving its complimentary colour to be transmitted. Particles so small that they absorb UV light (outside the visible range) transmit the full visible spectrum and look colourless. As the particle size increases (by small amounts) so the wavelength of the absorbed light increases, and the transmitted complimentary light changes, as noted above. Colour depth, ie the strength of a particular colour, is directly proportional to the concentration of the solution (as you surmise). This relationship (Beer-Lambert Law) is exploited by colorimeters and spectroscopy in determining concentration of solutions. Also, keep in mind that we are talking of solutions which exhibit no cloudiness. A cloudy solution contains some very large particles and should be filtered. Regards - Ivan PS I was writing this as you posted Chuck. I'm so predictable ;-) ==================== Being new to CS making I'm a bit confused about what appears to be a contradiction. Some listers brag about the nice deep golden color they get in their batches, yet others are proud of their clear, no color product. Which is right? Is more color better than no color at all? It would seem to me that if color is due to light refraction caused by silver ppm then the more color the more silver ppm. Please enlighten me. Best regards, Art -- 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]>
