CONCENTRATION AND SIZE DEPTH PROFILE OF COLLOIDAL SILVER PARTICLES IN GLASS SURFACES PRODUCED BY SODIUM SILVER ION-EXCHANGE

The sodium-silver ion exchange of a commercial soda-lime silicate glass followed by an annealing process yield small silver particles in a surface layer. Microspectrophotometry spectra and transmission electron microscopy show that the mean particle size increases with the penetration depth, whereas the volume concentration is constant. A model on the basis of a homogeneous nucleation including ion exchange, diffusion, reduction and particle formation is given. The measured depth dependence is described with the model by a non-linear system of differential equations.