PREPARATION OF COLLOIDAL SILVER DISPERSIONS BY THE POLYOL PROCESS .1.SYNTHESIS AND CHARACTERIZATION

Modification of the polyol process has enabled the synthesis of nanome tre-sized silver particles with a narrow size distribution. Dispersion s of colloidal silver have been prepared by the reduction of silver ni trate in ethylene glycol in the presence of a polymeric protective age nt, namely polyvinylpyrrolidone (PVP). Ageing these dispersions at 120 degrees C for 1 h yields systems with average particle sizes ranging from 15 to 36 nm. The amount of both precursor and protective agent wa s found to control the final particle size and size distribution of th e colloidal silver, which exhibits a well crystallized structure.