PVP保护还原法制备纳米金溶胶

Preparation of Nanogold Colloid by C hemical Reducing with PVP Protection

采用草酸还原较高浓度HAuCl4溶液的方法,在PVP作保护剂的水溶液中,成功制备出了粒度平均为20nm～30nm且高度分散的金溶胶。分别讨论了金溶胶制备过程中的各主要影响因素,如:pH值、还原剂浓度、保护剂用量及其加入方式等对金粒度分布与形状的影响。研究表明,制备稳定的纳米金溶胶的较优条件为:适中搅拌,pH值为4～5,还原剂与溶液中金质量比3∶1,PVP与金质量比为1∶1,反应温度343K可制得粒度为20nm的金胶体。把HAuCl4加入PVP与Na2C2O4的混合液中是较好的加入方式。

This paper deals with the preparation of nanogold colloid by chemical reducing gold from relatively with a solution of HAuO4 With HC2O4 as a reduction reagent and PVP as dispersion and stabilizer. The gold particles size of 20 nm - 25 mn were obtained under the given conditions. Some factors such as pH value, adding way, the amount of the HC2O4 and the PVP etc which affecting the particle size and shape of the nanogold in the colloids, are discussed, respectively. Optimal conditions obtained for making nanogold colloid with particle size less than 20nm are: pH = 4 similar to 5, Na2C2O4/Au = 3, PVP/Au = 1: 1, and at 343K. Adding HAuCl4 into the mixture of Na2S2O4 and PVP aqueous solution is a better way of operation. The new process is characterized by its simple operation, high productivity and lower cost.