"James Osbourne, Holmes" wrote: > I think it is a bit more complex: some are absorbed;
Right. > some are reflected; Right. > > some are refracted and the angles of reflection vary with wavelength; True, this is lumped together with reflected as scattering, and is ultimately what is termed Tyndall effect. > some > are absorbed and re-emitted at a different wavelength. I am not aware of any being absorbed and re-emitted, except for the energy from the light creates heat and the silver will have the black body radiation associated with the temperature. Normally absorbed and re-emitted is considered fluorescence, and I don't think silver behaves this way. Do you have any cites or references on this? > All of this changes > with particle size and concentration of particles. It changes with particle size, as I have quoted previously, the Tyndall increases to the third power with the size. The increase in Tyndall and absorption are both linear with concentration (provided the concentration does not reach a point where aggregation occurs).. > Some devices take > advantage of this behavior to determine particle size based on the changes > between the light in and light out. Yes, I have used this myself. Using the Hack scanning spectrophotometer, I scan a specimen and can get a crude idea of the particle size distribution from the absorption spectrum from infrared to uv. If I could obtain some samples with defined and narrow particle size ranges to calibrate from, I think I could do a very good job of using this technique to profile particle size of CS samples, but have not been able to source any such standards. Marshall -- 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] Silver-list archive: http://escribe.com/health/thesilverlist/index.html List maintainer: Mike Devour <[email protected]>
