次磷酸盐液相还原法快速制备纳米银粉

High-speed Preparation of Nanometer Silver by Reduction with Sodium Hypophosphite in Liquid Phase

以次磷酸钠为还原剂、六偏磷酸钠为分散剂、聚乙烯吡咯烷酮 (PVP)为保护剂 ,在 pH =1～ 2、温度为 4 0～ 4 2℃条件下与硝酸银溶液反应 ,得到紫红色银胶。经离心 (6 0 0 0r/min)分离、钝化剂溶液洗涤、真空干燥 (1× 10 3 Pa ,5 0℃ ) 3h ,得粉末状产物。透射电镜和X射线衍射仪分析表明 ,产品系粒径为 10～ 30nm纯相纳米银粉。本方法的制备周期约为 5h ,产率可达 70 %～80 %。

A silver colloid was prepared by reaction of silver nitrate solution with sodium hypophosphite(as reducer),sodium hexametaphosphate(as disperser)and polyvinylpyrrolidone(as protective agent)at pH=1-2 and 40-42 ℃.The silver colloid was centrifuged (6000 r/min) and washed with a passivating agent and organic solvents.Then the product was dried in vacuum oven(1×10 3 Pa,50 ℃)for 3 h. Diameters of the particles are between 10-30 nm as analyzed by transmission electron microscope(TEM) and no impurity is detected by X ray diffractomater(XRD).The period of preparation was about 5 h and the productivity was about 70%-80%.