Thanks Marshall, you are quite right, Russ mentioned the Tyndall Effect when really his question was about the general optical properties of CS, the explanation of which involves the rather complicated effects of plasmon excitation and extinction, Rayleigh scattering and Mie theory etc.
My mistake. Regards Ivan > -----Original Message----- > From: Marshall Dudley [mailto:[email protected]] > Sent: Thursday, 25 July 2002 2:38 a.m. > To: *Silver-List* > Subject: Re: CS>Particle size vs. color > > > Ivan Anderson wrote: > > > Hi Russ, > > > > > According to my understanding of the Tyndall effect, I > > > infer that this color > > > indicates that the diameter these particles of CS (+ > > > impurities) corresponds > > > to the wavelength of red light, ~700 nm, whereas yellow CS > > > particles would > > > be around 580 nm and clear CS would be >/= that of > > > color-less UV, below 380 > > > nm..............right?? > > > > No. The Tyndall Effect is only manifest when the particle is much > > smaller than the wavelength of light. For instance, gold > colloids look > > red when the particles are about 13nm in diameter. > > 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 > > > -- > 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]> > > --- > Incoming mail is certified Virus Free. > Checked by AVG anti-virus system (http://www.grisoft.com). > Version: 6.0.377 / Virus Database: 211 - Release Date: 15/07/2002 > --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.377 / Virus Database: 211 - Release Date: 15/07/2002
