聚乙烯吡咯烷酮及鞣酸对纳米金制备的影响

Effect of tannic acid and PVP for preparation of colloidal gold particles

在经典Frens法制备金纳米粒子过程中引入聚乙烯吡咯烷酮(PVP)及鞣酸作为保护剂,制备出金纳米粒子并考察了保护剂用量、反应温度和搅拌速度对制备出的金纳米粒子的影响;在制备好的金纳米粒子表面,通过化学还原方法沉积生长银层。利用UV-Vis分光光度计,透射电子显微镜(TEM)等手段对得到的样品进行表征。结果表明:两种保护剂的存在可提高粒子的稳定性、单分散性、粒径分布均匀且在7 nm^25 nm内可控,重现性好;Au/Ag核壳结构复合粒子在适当的摩尔比范围内粒径可控且均匀稳定。

Tannic acid and PVP were added as protecting agents in the reaction process for formation of colloidal gold nano- particles by using traditional Frens method. The improved method simplifies previous preparation operations. （Au）core ＊（Ag）shell composite nano - particles were prepared by deposition of Ag through chemical reduction in the presence of Au nano- particles. UV - vis spectroscope and transmission electron microscope （TEM） were used for the observation of samples prepared using various stablizers amounts, temperature and the rate of stirring and its composite. The experimental results showed that： the addition of the two kinds of protecting agent can prevent further growth of the particles, get better mono - dispersivity and more steady particles in 7 nm - 25 nm with good controllability and reproducibility. Also, the size of bimetallic particles can be controlled within a suitable range of molar ratio of Ag to Au.