含生物质的水溶性纳米银粉的制备

生物还原法是近年来一种新兴的纳米材料的制备方法,利用生物还原法制备银溶胶时,由于受到生物质分子良好的保护作用,产物具有高分子溶液的性质,极为稳定,采用普通的离心方法无法将其分离回收.因此,采用乙醇或丙酮等有机溶剂来回收银溶胶,真空干燥后制得水溶性纳米银粉,该法具有比盐析法更好的分辨能力,沉淀无需脱盐,简单易行.X射线粉末衍射和透射电镜的表征结果证明,该回收过程中银晶粒基本保持生物还原后的纳米尺度,颗粒水溶性、分散性好;原子吸收分光光度计测试所得纳米银粉中银的质量分数在60%～80%之间.

Preparation of Water-soluble Nanosilver Powder Contained Biomass

Bioreduction is a novel method of preparing the nanostructured material.The silver sol synthesized by bioreduction had the property of macromolecular solution which couldn′t be recovered by simple centrifugal separation due to the protective function of biomass.In this paper,a kind of water-soluble nanosilver powder was prepared by precipitating the silver sol with organic solvent as precipitator,such as ethanol and acetone,and treated with vacuum drying at room temperature.This process is easy to operate without eliminating and also has better resolving power compared to salting-out.The results of XRD and TEM indicate that the silver particles can basically keep their original size after precipitation.The silver mass content of the silver powder is among 60%～80% determined through AAS.