ABSORPTION-SPECTRA OF LARGE COLLOIDAL SILVER PARTICLES IN AQUEOUS-SOLUTION

Calculations of the optical absorption spectra of spherical particles of silver with a radius (r) of 10 to 80 nm in water were performed. Th e single intense absorption band for small particles (r approximate to 10 nm) with a maximum at about 395 nm is gradually broadened and shif ted to the long-wave region with an increase in the particle size (to 435 nm at r = 40 nm). In the case of large particles, the band splits into several components absorbing light in the visible spectral region . The results are in good agreement with the optical characteristics o f colloidal solutions of silver obtained upon radiochemical reduction of Ag+ ions in aqueous solution.