室温制备纳米银醇溶胶

Room-Temperature Preparation for Ethanol Colloid of Silver Nanoparticles

在室温下制备了分散性好、稳定性好、粒径分布均匀的高浓度纳米银醇溶胶。采用透射电子显微镜(TEM)、紫外可见光谱(UV-Vis)对产物的形貌和光学性能进行表征。结果表明,所制备的纳米银为分散均匀的球形粒子,平均粒径为4.8nm。在此反应过程中,聚乙烯吡咯烷酮(PVP)既作保护剂又作还原剂,作为溶剂的乙醇有利于PVP分子链的舒展,增大了PVP分子与Ag+的接触几率,促进了还原反应的快速进行;另一方面,充分舒展的PVP分子能有效抑制银纳米粒子团聚。

Stable concentrated ethanol dispersions of silver nanoparticles with a narrow size distribution were obtained at room temperature. The morphology and optical properties of the silver nanoparticles were characterized by transmission electron microscope （TEM） and visible spectrophotometer （UV-Vis）. The results show that the silver particles possess spherical shape with an average diameter of about 4.8 nm with a good dispersion. During the preparation process, poly（vinyl pyrrolidone） （PVP） is used both as a reducing agent and a protecting agent and ethanol is used as a solvent that could rapidly reduce Ag＋ in favor of a positively optimum extension of PVP molecule chain which increases the contact chance between PVP and Ag＋. Moreover, the PVP molecule of full extension could effectively avoid aggregation of silver nanoparticles.