Preparation and dispersive mechanism of highly dispersive ultrafine silver powder
Preparation and dispersive mechanism of highly dispersive ultrafine silver powder
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DOI：
10.1016/j.apsusc.2010.04.070
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发表时间：
2010-09-01
影响因子：
6.7
通讯作者：
Liu, Huan
中科院分区：
文献类型：
--
作者：
Guo, Guiquan;Gan, Weiping;Liu, Huan
以抗坏血酸为还原剂，硝酸银为银源，采用液相还原法制备超细银粉。在其他条件不变的情况下，研究了分散剂的选择、分散剂用量、pH值等因素对银分散性的影响，得到了制备超细银的最佳工艺条件。以聚乙烯醇（PVA）为分散剂，PVA/AgNO 3质量比为4：1，在最佳条件下合成了平均粒径为1.15 μ m的准球形纯超细银粉。100和pH 7，同时在完全相同的情况下保持其他条件，如AgNO 3浓度为0.20 mol L-1，抗坏血酸浓度为0.15 mol L-1，反应温度为40 ℃。用SEM和XRD对超细银粉进行了表征。紫外光谱分析表明，PVA在制备高分散性超细银粉中的分散机理是PVA通过配位键吸附在银粒子表面，阻止了银粒子的扩散和聚集。此外，空间效应可能有助于减少聚集。(C)2010 Elsevier B. V.保留所有权利。
Using ascorbic acid as the reducing agent, AgNO3 as the source of Ag, the ultrafine silver powder was prepared by liquid-phase reduction method. The optimal conditions to prepare the ultrafine silver powder were obtained by studying the effects of following factors, such as the selection of dispersant, the doses of dispersant and pH, on the dispersibility of silver powder under other constant conditions. The pure ultrafine silver powder with quasi-spherical shape and mean size of 1.15 mu m was synthesized under the optimal conditions of polyvinyl alcohol (PVA) as disperser, PVA/AgNO3 mass ratio of 4: 100 and pH 7 while maintaining other conditions exactly in the same circumstances, such as AgNO3 concentration of 0.20 mol L-1, ascorbic acid concentration of 0.15 mol L-1 and reaction temperature of 40 degrees C. The ultrafine silver powder was characterized by SEM and XRD. And a PVA dispersive mechanism for preparing highly dispersive ultrafine silver powder, proved by the ultraviolet spectra, is that PVA absorbed on the surface of silver particles by coordination bond preventing the silver particles from diffusion and aggregation. In addition, the steric effect may help to reduce aggregation. (C) 2010 Elsevier B.V. All rights reserved.