水-乙醇体系中胶体金纳米粒子的吸收光谱变化  

The change of absorption spectrum of colloidal Au particles in water-ethanol solution

作　　者：王春霞[1] 王永[1] 王声乐[2] 付德刚[1] 

机构地区：[1]东南大学生物电子学国家重点实验室,南京210096 [2]东南大学物理系,南京210096

出　　处：《中国科技论文在线》2007年第4期304-308,共5页

摘　　要：在水相中用硼氢化钠还原AuCl4-,获得了稳定分散并且颗粒大小均一的胶体金纳米粒子,并进一步向溶液中加入乙醇,控制溶液中水和乙醇的体积比来改变胶体金的外围介质。通过理论分析和实验结果的比较,阐明了球形金纳米粒子在水-乙醇体系中的光谱特性及其变化趋势,发现乙醇的加入同时改变了周围介质的介电常数和胶体金的表面双电层结构,两种变化对粒子吸收光谱有相反的影响。Stable colloidal Au particles with mean diameter about 5nm in water solution are obtained by reduction of AuCl4-using NaBH4.The wavelength and strength of surface plasma resonance（SPR） absorption of colloidal Au particles vary with ratio of ethanol to water in the solution.This has been attributed to the change of surrounding medium around Au nanoparticles after addition of ethanol into the colloidal solution.It is found that the addition of ethanol could modify both solution dielectric function and the double-electrical layers structures of Au particles,which induces opposite effects on SPR wavelength of colloidal Au particles.

关 键 词：吸收光谱 等离子共振 纳米金 双电层 介电常数 

分 类 号：TB383.1[一般工业技术—材料科学与工程]