Preparation and characterization of nano-sized Ag/PVP composites for optical applications

Abstract:

A modification of the polyol process has enabled the direct synthesis of nm-sized Ag particles with narrow size distribution and controlled average dimension embedded in a polymeric matrix. Dispersion of colloidal silver was obtained by reduction of silver nitrate in ethylene-glycol in the presence of a polymeric protective agent (i.e., poly(N-vinylpyrrolidone)) and ultrasounds. The final particle size was controlled by removing the colloid from the reactive mixture by addition of acetone. The very strong plasmon resonance peak at 410 nm and a feature at 350 nm in the UV-visible spectra are a clear consequence of the nano-size of dilute Ag particles. The proposed process offers the possibility to effectively use these synthesised materials for the production of colour filters for advanced optical devices.