《电工材料》

采用化学还原法，通过3种不同还原剂体系(氨水-水合肼、抗坏血酸、氢氧化钠-葡萄糖)可从硝酸银溶液中制备出高分散性超细银粉。具体工艺如下：采用氨水-水合肼还原体系时，需控制反应pH处于10～10.5，且快速加入水合肼溶液，可制备出D₅₀=1.15μm的超细银粉；采用抗坏血酸溶液还原时，控制反应pH为6，可制备出D₅₀=1.53μm超细银粉；采用氢氧化钠-葡萄糖还原体系时，需先通过氢氧化钠与硝酸银反应生成氢氧化银晶粒，作为稳定粒径和高分散性的前驱体，再快速加入葡萄糖溶液进行反应，可制备D₅₀=0.80μm的超细银粉。

Highly dispersed ultrafine silver powders can be prepared from silver nitrate solution via the chemical reduction method, using three different reductant systems: ammonia-hydrazine hydrate, ascorbic acid, and sodium hydroxide-glucose. The specific processes are as follows: when the ammonia-hydrazine hydrate reduction system was adopted, the reaction pH was controlled within the range of 10～10.5, and hydrazine hydrate solution was added rapidly, thus obtaining ultrafine silver powders with a D₅₀ of 1.15 μm. When ascorbic acid solution was used as the reductant, the reaction pH was maintained at 6, and the resulting ultrafine silver powders exhibited a D₅₀ of 1.53 μm. When sodium hydroxide-glucose reduction system was used as the reductant, silver hydroxide crystals were first synthesized via the reaction between sodium hydroxide and silver nitrate, which served as the precursor to ensure uniform particle size and high dispersibility. Subsequently, glucose solution was added rapidly to conduct the reduction reaction, finally yielding ultrafine silver powders with a D₅₀ of 0.80 μm.