明胶作分散剂制备球形超细银粉

Preparation of Spherical Ultra-fine Silver Powder Using Gelatin as Dispersant

采用化学还原法,以抗坏血酸为还原剂,明胶为分散剂制备了球形超细银粉。探讨了反应过程中AgNO3溶液浓度、反应液pH值、明胶用量、试剂滴加顺序等因素对银粉粒度大小及分布的影响。在pH为7时,将0.5mol/L的AgNO3溶液加入到0.25mol/L的抗坏血酸溶液中,明胶用量为AgNO3质量的1.5%,且在产生沉淀后逐滴加入能制备出大小1.5μm左右,粒度分布均匀的球形超细银粉。

Using ascorbic acid as reducing agent and gelatin as dispersant, the spherical ultra-fine silver powder was synthesized by the chemical reduction method. The influence of AgNO3 solution concentration, pH value, gelatin dosage and reagents adding orders on the diameter of silver particles and particle distribution were studied. The spherical ultra-fine silver powder with the diameter of about 1.5 μm and homogeneous particle size distribution is prepared under the conditions as following： adding 0.5 mol/L AgNO3 solution into 0.25 mol/L ascorbic acid solution, gelatin dosage 1.5% of AgNO3 mass, adding gelatin drop by drop after the precipitate appearing, and pH=7.