Preparation of colloidal silver dispersions by the polyol process. Part 1—Synthesis and characterization

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