POLYMER PROTECTIVE MECHANISM OF NANOMETER SILVER POWDER PREPARED BY CHEMICAL-REDUCTION METHOD

Nanometer silver grain growth and particle's aggregation were effectiv ely prohibited by polyvinyl pirrolidon (PVP) when the silver powder pr epared from silver nitride solution reduced by hydrazine hydrate. On t he base of ultraviolet spectra and FTIR spectra measurement, PVP prote cting mechanisms proposed in this paper were that, first, the coordina tive bonds were formed between PVP and silver ions; secondly, a large number of silver embryos were generated during the initial reaction pe riod due to the coordinative bonds formation; and finally, silver embr yos and the PVP steric effects were responsible for the inhibited grai n growth and the grain aggregation of silver particles.