Synthesis and characterization of fine and monodisperse silver particles of uniform shape

• Published in: Journal of solid state chemistry 1992-10, Vol.100 (2), p.272-280
• Main Authors: Ducamp-Sanguesa, C., Herrera-Urbina, R., Figlarz, M.
• Format: Article
• Language: English
• Subjects: Chemistry; Colloidal state and disperse state; Exact sciences and technology; General and physical chemistry; General, apparatus, technics of preparation
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1016/0022-4596(92)90101-Z

Fine silver particles of uniform size and shape have been synthesized from silver nitrate in hot ethylene glycol. Quasi-spheric and monodisperse silver particles are produced only when particle sintering is prevented during the growth step. For this purpose, a protective agent, namely, polyvinylpirrolidone (PVP), was added to the system. Particle size increases with increasing temperature and PVP/silver nitrate weight ratio. Heterogeneous nucleation of metallic silver with a critical concentration of in-situ formed platinum nuclei produces monosize particles that have a rod-like shape. This drastic change in particle shape indicates that under these conditions PVP also acts as a crystal habit modifier. The thickness of rod-like particles changes when different PVP/silver nitrate weight ratios are used. Electron microscopy and X-ray diffraction techniques were used for particle characterization. The synthesis of metallic particles in liquid polyols, which act as both solvent and reducing agent, is a useful method for producing highly pure, fine, and monodisperse particles of uniform shape.