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以无机盐硝酸银为原料,银氨络合物为前驱体,采用真空冷冻干燥法制备了银纳米粉体。本文在实验中采取了三种冷冻方式:直接冷冻、真空蒸发冷冻和喷雾冷冻。经透射电镜(TEM)、X-射线衍射(XRD)和X射线能谱(EDS)检测,所制备的粉体为颗粒细小、粒度分布狭窄、形状规则、无硬团聚、非晶体的纳米粉体。三种冷冻方式制备的样品的粒径依次为5 nm~40 nm3、nm~10 nm和3 nm~5 nm,粉体煅烧后转变为粒径为10 nm~50 nm的立方晶体。文中给出了银纳米粉体的具体制备过程和化学原理,并根据检测结果,讨论了冷冻方式对所制备粉体品质的影响和真空冷冻干燥法制备粉体物质形态特点的微观机制。
Inorganic silver nitrate as raw material, silver ammonia complex as a precursor, the use of vacuum freeze-dried silver nanoparticles prepared. In this paper, three kinds of freezing methods are adopted in the experiment: direct freezing, vacuum evaporation freezing and spray freezing. The powders were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDS). The prepared powders were fine particles with narrow particle size distribution, regular shape and no agglomeration. . The diameters of the prepared samples were 5 nm ~ 40 nm3, nm ~ 10 nm and 3 nm ~ 5 nm, respectively. The calcined powders were transformed into cubic crystals with particle sizes of 10 nm ~ 50 nm. In this paper, the specific preparation process and chemical principle of silver nanopowder are given. According to the test results, the influence of the freezing method on the quality of the prepared powder and the microscopic mechanism of the morphological characteristics of the powder material prepared by the vacuum freeze-drying method are discussed.