分步还原法制备电子浆料用球形银粉及其形貌与粒径  

Morphology and particle size of micro spherical silver fabricated by multistep reduction

作　　者：李碧渊 甘卫平[1] 黎应芬[1] 周健[1] 王晓庆[1] 

机构地区：[1]中南大学材料科学与工程学院,长沙410083

出　　处：《粉末冶金材料科学与工程》2016年第1期109-115,共7页Materials Science and Engineering of Powder Metallurgy

摘　　要：采用分步还原法制备银粉,即以硝酸银为银源,硼氢化钠为还原剂制备出晶种,然后还原硝酸银制备银粉,通过扫描电镜(SEM)和X射线衍射分析,研究还原剂的种类、晶种数量、溶液体系中还原剂的浓度及硝酸银浓度对银粉形貌和粒径的影响。结果表明:采用强还原剂制备的银粉团聚严重,粒径不均匀;当体系中还原剂浓度太小(0.05 mol/L)或太大(0.25 mol/L)时,银粉粒径很小,团聚严重;当加入的晶种数量较少时(1 m L),银粉粒径不均匀,而当晶种数量较大(3 m L)时,银粉粒径很小,团聚严重;随硝酸银的浓度从0.05 mol/L增加到0.20 mol/L,银粉粒径先增大后减小。采用还原性较弱的抗坏血酸为还原剂,晶种体积为2 m L,体系中C6H8O6和Ag NO3的浓度均为0.15 mol/L时,制备出表面光滑、分散性较好、粒径均匀、粒度为1.5μm的球形银粉。Sodium borohydride was used as reducer to prepare silver seed, and then the silver nitrate was reduced step-by-step in aqueous solution to fabricate micron silver powder. The effects of reducing agent, the amount of silver seed, the concentration of reducer and silver nitrate on the size and morphology of the silver particles were studied. SEM and X-ray diffraction were used to characterize the surface morphology and crystal structure of silver particles. The results show that the silver powder prepared with strong redusing agent agglomerates seriously and the particle size is non-uniform; when reduction agent concentration is too low（0.05 mol/L） or too high（0.25 mol/L）, the silver particle is very small and agglomerates seriously; when adding fewer volume of crystal seeds（1 m L）, the silver particle is non-uniform, and when adding more volume of seeds（3 m L）, the silver powder is fine and agglomerates seriously; spherical silver particles with better dispersibility and uniform particle size can be obtained by using 2 m L of silver seed and weak reducing agent（ascorbic acid） when the concentration of ascorbic acid is 0.15 mol/L. With the increase of concentration of silver nitrate from 0.05 mol/L to 0.20 mol/L, the particle size of silver particle increases first and then decreases. When the concentration of silver nitrate is 0.15 mol/L, the spherical silver particle with average size of 1.5 μm has smooth surfaces, better dispersibility and uniform particle size.

关 键 词：分步还原 抗坏血酸 球形银粉 化学还原 

分 类 号：TF123.73[冶金工程—粉末冶金]