Was there any discussion on how these nanoparticles were produced? I suppose it's not something the average person could make?
-Ken Bagwell --- Marshall Dudley <[email protected]> wrote: > Ode Coyote wrote: > > > "Scientists studied the absorption spectra of the > different preparations > > to pinpoint their shapes. "Spherical nanoparticles > absorbed in the blue > > region of the spectrum, for example," Yacaman > said." > > > > ## So, "color" isn't 'entirely' about size, but > is something much more > > complex especially when shapes of impure crystals > can vary in a fractal > > pattern according to the nucleating particle > center that the crystal grows > > upon. > > Yes, this is known, and covered in some of the > references I have posted in the > past. Basically a silver particle is like a small > antenna, and will have a > resonant frequency. Light at the resonant frequency > will be absorbed, and as > the particle increases in size, then the resonant > frequency decreases (resonant > frequency will be 4 times the length of time it > takes for electricity to travel > from one margin of the crystal to another, just like > with a 1/4 wavelength > antenna), moving the absorption band from uv, to > violet, blue, green, yellow, > orange, red, and infrared as the crystal grows > larger. The apparent color is > of course the complement of the absorbed color. > > Now if you make an antenna in the shape of a > snowflake, you will have a myriad > of resonances, some low frequency across the whole > flake, but others within the > center, arms and areas at the end of the arms, each > having their own > resonances, and these will all be much higher > resonances than the one across > the whole thing. Exactly the same thing happens with > silver crystals, except > the frequencies are not in the radio range, but the > light ranges. The physics > is actually quite well understood, although > computing all the resonances for an > irregular shape becomes difficult if not impossible. > > Marshall > > > > -- > The Silver List is a moderated forum for discussing > Colloidal Silver. > > Instructions for unsubscribing are posted at: > http://silverlist.org > > To post, address your message to: > [email protected] > Silver List archive: > http://escribe.com/health/thesilverlist/index.html > > Address Off-Topic messages to: > [email protected] > OT Archive: > http://escribe.com/health/silverofftopiclist/index.html > > List maintainer: Mike Devour <[email protected]> > > __________________________________ Yahoo! Mail - PC Magazine Editors' Choice 2005 http://mail.yahoo.com
