Zhang Li, Shen Yuhua, Xie Anjian, Li Shikuo, Jin Baokang, Zhang Qingfeng
School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039, PR China.
J Phys Chem B. 2006 Apr 6;110(13):6615-20. doi: 10.1021/jp0570216.
The monodisperse silver nanoparticles were synthesized by one-step reduction of silver ions in the alkaline subphase beneath vitamin E (VE) Langmuir monolayers. The monolayers and silver nanocomposite LB films were characterized by surface pressure-area (pi-A) isotherms, transmission electron microscopy (TEM), ultraviolet-visible spectroscopy (UV-vis), selected area electron diffraction (SAED), Fourier transform infrared transmission spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS), respectively. The results showed that the limiting area/VE molecule on different subphases varied. The phenolic groups in the VE molecules were converted to a quinone structure, and the silver ions were mainly reduced to ellipsoidal and spherical nanoparticles. The arrangement of the nanoparticles changed from sparseness to compactness with reaction time. The electron diffraction pattern indicated that the silver nanoparticles were face-centered cubic (fcc) polycrystalline. Silver nanocomposite LB films with excellent quality could be formed on different substrates, indicating that the transfer ratio of monolayer containing silver nanoparticles is close to unity. The dynamic process of reduction of silver ions by VE LB films was also studied through monitoring the conductivity of an Ag2SO4 alkaline solution.
通过在维生素E（VE）朗缪尔单分子层下方的碱性亚相中一步还原银离子来合成单分散银纳米颗粒。分别通过表面压力-面积（π-A）等温线、透射电子显微镜（TEM）、紫外-可见光谱（UV-vis）、选区电子衍射（SAED）、傅里叶变换红外透射光谱（FTIR）和X射线光电子能谱（XPS）对单分子层和银纳米复合LB膜进行了表征。结果表明，不同亚相上VE分子的极限面积不同。VE分子中的酚羟基转化为醌结构，银离子主要还原为椭球形和球形纳米颗粒。随着反应时间的延长，纳米颗粒的排列从稀疏变为致密。电子衍射图谱表明银纳米颗粒为面心立方（fcc）多晶。可以在不同的基底上形成质量优异的银纳米复合LB膜，这表明含银纳米颗粒的单分子层的转移率接近1。还通过监测Ag2SO4碱性溶液的电导率研究了VE LB膜还原银离子的动态过程。
