摘要
以不同平均分子质量的聚乙烯吡咯烷酮(PVP,通常用K值来表示PVP溶液相对粘度的特征值,粘度越大,PVP平均分子质量越大,平均分子质量为8000、40000、160000、360000的PVP分别标记为K17、K30、K60、K90)为表面活性剂,通过水热法合成了形貌和光学共振峰可控的银纳米结构.将反应体系加入到60 mL的不锈钢高压反应釜中,在一定的温度下加热数小时.我们在K17的水溶液中合成了尺寸均一的五重孪晶银纳米十面体.而在K30、K60和K90的乙二醇(EG)溶液中得到了纵横比随着PVP分子质量增大而增大的银纳米线.产物的形貌和微结构通过透射电镜(TEM)和场发射扫描电镜(FE-SEM)进行表征,表面等离子共振(SPR)吸收峰通过紫外-可见分光光度计进行测试,结果显示银纳米结构的表面等离子共振随着其形貌和尺寸的改变而发生变化.
Ag nanostructures with wel-defined shapes and optical resonances have been mass-synthesized by a hydrothermal method. Polyvinylpyrrolidone （PVP） polymers with average molecular weights （MW） of 8000, 40000, 160000, and 360000 denoted as K17, K30, K60, and K90, respectively, were chosen as surfactants （K is usual y used to represent the characteristic value of relative viscosity of the PVP solution）. It was found that the larger MW of PVP, the higher relative viscosity of the PVP solution. Al of the reactants were transferred into a 60 mL stainless steel autoclave and heated at a certain temperature for hours. Five-fold twinned Ag nanodecahedrons with nearly uniform size were synthesized in the aqueous solution of K17. Ag nanowires were obtained with the presence of K30, K60, and K90 in ethylene glycol （EG） solution, and the aspect ratios of the Ag nanowires increased with increasing the MW of PVP. The morphology and microstructures of the obtained products were characterized by transmission electron microscopy （TEM） and field emission-scanning electron microscopy （FE-SEM）. The surface plasmon resonance （SPR） spectra of the Ag nanostructures were measured using an UV-Vis spectrophotometer. The results showed that the surface plasma resonance of the Ag nanostructures was dependent on their shape and size.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2014年第3期569-575,共7页
Acta Physico-Chimica Sinica
基金
supported by the National Natural Science Foundation of China(11274173,51032002,61222403,11374159)
FundamentalResearch Funds for the Central Universities,China(NZ2013304)~~
关键词
银纳米线
五重孪晶
十面体
聚乙烯吡咯烷酮
生长机制
Ag nanowire
Five-fold twinned crystal
Decahedron
Polyvinylpyrrolidone
Growth mechanism
