乙二醇中化学还原合成片状银粉

研究了乙二醇（EG）介质中以聚乙烯吡咯烷酮（PVP）为保护剂，以氯铂酸为催化剂以硝酸银为前驱物经化学还原制备片状银粉的过程,探索与分析影响银粉形貌的主要因素.结果表明,首先被还原出来的铂成为外来晶种,是形成片状银的关键因素.它在原位为随后还原与沉淀的银提供一个平面.PVP与银离子形成络合离子,控制游离银离子的浓度,影响银的成核与生长.同时,PVP被选择性地吸附于银的粒子表面,影响了银成核与生长,最终形成片状银粉.

Mechanism for the Formation of Flake Silver Powder Synthesized by Chemical Reduction in Ethylene Glycol

The chemical reduction process has been used for the synthesis of silver powder in ethylene glycol.The mechanism for the formation of flake powder has been proposed on the basis of analysis of the main factors influencing the morphology of silver powder.The results showed that the key factor for the formation of flake silver powder was the heterogeneous seeds of platinum firstly reduced.It offered a plane for precipitation and reduction of silver later.The concentration of free silver ion was controlled by polyvinyl pyrrolidone (PVP) by the formation of complex.And more PVP was absorbed on the surface of silver ion selectively. Thus the nucleation and growth of silver was influenced and flake silverpowder formed.