分步还原法制备电子浆料用球形银粉及其形貌与粒径.pdf

第21卷第1期
粉末治金材料科学与工程
2016年2月
Materials Science and Engineering of Powder Metallurgy
Feb.2016
分步还原法制备电子浆料用球形
银粉及其形貌与粒径
李碧渊,甘卫平,黎应芬,周健,王晓庆
(中南大学材料科学与工程学院,长沙410083)
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(0.05molL)或太大(0.25mol)时,银粉粒径很小,团聚严重:当加入的晶种数量较少时(1mL),银粉粒径不均
匀,而当晶种数量较大(3m)时,银粉粒径很小,团聚严重:随硝酸银的浓度从0.05moML增加到0.20moL,
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2mL,体系中 CSSO和AgNO2的浓
度均为0.15molL时,制备出表面光滑、分散性较好、粒径均匀、粒度为1.5um的球形银粉。
关键词:分步还原;抗坏血酸;球形银粉;化学还原
中图分类号:TF123.73
文献标志码:A
文章编号:1673-0224(2016)01-10907
Morphology and particle size of micro spherical silver fabricated b
multistep reduction
LI Biyuan, GAN Weiping, LI Yingfen, ZHOU Jian, WANG Xiaoging
(School of Materials Science and Engineering, Central South University, Changsha 410083, China)
Abstract: 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(.05 mol/)or too high (0.25 mol/L), the silver particle is
very small and agglomerates seriously; when adding fewer volume of crystal seeds(I ML), the silver particle is
non-uniform, and when adding more volume of seeds (3 ML), the silver powder is fine and agglomerates seriously;
spherical silver particles with better dispersibility and uniform particle size can be obtained by using 2 ML of silver seed
and weak reducing agent (ascorbic acid ) when the concentration of ascorbic acid is 0.15 mo L. With the increase of
concentration of silver nitrate from 0.05 mo/L to 0.20 mo / 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 um
mooth surfaces, better dispersibility and uniform particle
Key words: multistep reduction; ascorbic acid spherical silver; chemical reduction; silver nitrate; sodium borohydride
贵金属银粉具有良好的导电性和催化性能,在电得到广泛应用。银粉作为电子浆料用的导电相,要求
子浆料引、喷界印刷、催化5?、传感器阻?等领域具有良好的分散性,形貌为球形或类球形,平均粒径
收稿日期:2015-04-16:修订日期:2015-07-07
通信作者:甘卫平,教投。电话:13707311733;E-mai:gwp@. csu.edu cn