从银氨溶液中还原法制备银粒子
摘要：本文采用化学还原法来制备银粒子，以硝酸银制成的银氨溶液为银的提供者，以甲醛为还原剂。考察了合成条件对（还原剂的用量，反应温度和反应时间等）对银粒子生成速度、粒子形貌及粒子大小的影响。研究结果表明：还原剂与银氨溶液的比例是影响反应结果的最主要因素，0.2mol/L AgNO3 银氨溶液用量与36-40%HCHO的体积比应该在1：1.5左右，比例如果小于1：1.5，则制得的银粒子团聚现象较为明显，如果比例大于1:1.5，则制得的银粒子团聚现象虽然不明显，但是未团聚的银粒子颗粒较大。而反应温度和反应时间的改变只是变相的影响了这个比例，造成了结果的不同: 反应的温度越低，制得的银粒子的尺寸越小，本文来自优~文^论#文,网，毕业论文 www.youerw.com 加7位QQ324.9114找源文反应温度越高，制得的银粒子的尺寸越大, 反应的时间越短，制得的银粒子尺寸越小，反应时间越长，制得的银粒子的尺寸越大。
关键词：银氨溶液；甲醛；反应温度；反应时间；还原剂用量
Preparation of Silver Particle from Silver Ammonia Solution by Reduction Method
Abstract: In this paper, silver particles was prepared by chemical reduction method, in which silver nitrate was the provider of silver and formaldehyde was used as the reducing agent. The effects of synthesis conditions (amount of reducing agent, reaction temperature and reaction times) on reducing rates and morphologies of silver particles were studied. The results showed that the ratio of the reducing agent to silver ion was the main factor. The optimized ratio of Ag+ to HCHO is 1: 1.5. The agglomeration phenomenon will be obvious if the ratio was less than 1: 1.5. If the ratio is greater than 1: 1.5, the prepared silver particle will become larger even though the agglomeration phenomenon get less obvious. The reaction temperature and the reaction time of change also affect this ratio, resulting in a different result: reaction temperature is low, the prepared silver particle size is small, the higher the reaction temperature, the larger the silver particles size is, the shorter the reaction time, the smaller the silver particles is, the longer the reaction time, the larger the prepared silver particles size is.
Key words: silver ammonia solution; formaldehyde; reduction method
目 录
1 前言1
1.1关于纳米银离子的概述1
1.1.1纳米银粒子的定义1
1.1.2纳米银粒子的特性1
1.1.3纳米银粒子的应用1
1.1.1纳米银粒子的前景2
1.2纳米银粒子的制备2
1.2.1电化学阳极牺牲法2
1.2.2化学还原法3
1.2.3银氨络离子还原生成银粒子5
1.3本课题的方案论证及研究内容7
2 实验9
2.1试剂及仪器9
2.1.1试剂9
2.1.2仪器9
2.2实验过程9
2.2.1银氨溶液的制备9
2.2.2还原剂用量实验10
2.2.3反应温度实验10
2.2.4反应时间实验11
2.3实验机理12
2.4实验产物的提取12
2.5实验产物的分析13
3 实验结果与讨论14
3.1还原剂用量实验14
3.2反应温度实验16
3.3反应时间实验18
4 结论21
致谢22
参考文献23,2850
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