【作者】 殷杰；

【导师】 尹光福；

【作者基本信息】 四川大学 ， 生物医学工程， 2006， 硕士

【摘要】 银是一种重要的贵金属,银被广泛应用于抗菌材料、医药材料、装饰材料、电子浆料、催化剂等领域。近年来,随着高新技术的发展,纳米银粉材料获得迅速发展。由于纳米银粉具有纳米材料所特有的体积效应、表面效应、量子尺寸效应等,在抗菌、医药、超导及光学等方面显示出普通银粉所不及的特殊功效,是一种应用前景广阔的新型材料。本研究采用液相化学还原法制备纳米银粉。该法工艺条件易控制,设备要求相对不高,可获得粒度分布较窄的纳米银粉,且产率高,既便于实验室研究,也便于工业化大规模生产。实验中选用硝酸银为原料,次磷酸钠为还原剂,PVP为高分子保护剂,六偏磷酸钠为分散剂,制备了类球状、分散性良好的纳米银粉。实验研究发现,较佳反应温度是40 ~ 50℃,反应剂用量的较佳比例是次磷酸钠的用量为理论用量的2 ~ 3倍,PVP的用量为硝酸银质量的1.0 ~ 1.2倍,六偏磷酸钠的质量为硝酸银质量的0.1 ~ 0.2倍。对自然干燥、真空干燥及冷冻干燥三种干燥方式进行对比发现,用任一干燥方法,所得的纳米银粉经XRD检测均为纯金属银,自然干燥时间长,真空干燥所得银粉的纯度较高,冷冻干燥所得的银粉不结块、粉末细。水浴温度50℃,硝酸银3.40g加入20ml去离子水中配制硝酸银溶液,次磷酸钠1.325 g、PVP 3.80 g、六偏磷酸钠0.43 g、水125 ml配制还原液,所制得的纳米银溶胶,由有机碱性混合试剂调节pH,再使用快T溶液分散。经TEM、XRD、纳米激光粒度分析仪等检测,通过该较佳工艺条件制得的纳米银粒子纯度高,平均粒径小,粒径分布窄;粒子类球状,并且分布均匀。分别采用定性和定量两种实验方式,研究了本实验制备的纳米银粉的抗菌更多还原

【Abstract】 Silver is one of the important precious metals. It has been widely used as antibacterial material, medical material, optical material, ornamental material, catalytic material, electrical and electronical materials, etc. Due to their peculiar properties caused from the volume effect, the surface effect, the quantum dimension effect, and the macro-quantum tunnel effect, the silver nanoparticles might become to the prospective important materials applied potentially in many field.There are many methods to prepare silver nanoparticles, in which the liquid-phase chemical reduction process is more controllable and easier in large-scale production. In this study, the silver colloids were prepared by the chemical reduction in liquid phase with silver nitrate, sodium hypophosphite (as reducer), sodium hexametaphosphate (as disperser), and polyvinylpyrrolidone (as protective agent). Through controlling reaction condition, the spheroid, dispersible and the stable silver colloids were prepared, and the optimum technologic has been summarized. The dispersible and stable silver colloid was synthesized at 50℃and reaction for 1 hour in the system of C(AgNO3)=1.0 mol/L, C(NaH2PO2·H2O)=0.1 mol/L, 2~3 times theoretical dosage of Na2PO4, m(PVP)/m(AgNO3) = 1.0~1.2, m([NaPO3]6)/ m(AgNO3)= 0.1~0.2, pH=1~2. The silver nanoparticles were obtained through desiccation of the colloid, and were characterized by XRD and TEM. The results showed that the product was the spherical silver particles with the mean size about 7~10 nm and without impurity almost.The antibacterial and bacteriostatic effects of silver nanoparticles to two index-bacteria (Escherichia coli, Bacillus subtilis) have been studied qualitatively and quantitatively. The antibacterial experimental results showed that the silver nanoparticles could effectively kill and更多还原