Wadkar Mihir M, Chaudhari Vijay R, Haram Santosh K
Department of Chemistry, University of Pune, Ganeshkhind, Pune 411007, India.
J Phys Chem B. 2006 Oct 26;110(42):20889-94. doi: 10.1021/jp063422p.
Stable organosols of silver nanoparticles (AgNPs) without any capping agents have been synthesized by an electrochemical dissolution of a sacrificing silver electrode in dimethyl sulfoxide (DMSO). The peak at 425 +/- 5 nm observed in the UV-vis spectra was attributed to the surface plasmon resonance for silver. The formation of nanoparticles of silver was confirmed by X-ray diffraction analysis (XRD). In TEM, three ranges of particle size were observed, namely, 3.75 +/- 0.8, 6.25 +/- 0.5, and 9.25 +/- 0.3 nm. The correlation among these sizes was explained by a new model based on a droplet coalition. Based on that, sizes correlation fits very well in the empirical formula 5d(1)(3)n' + (3 - n')d(2)(3) = d(3)(3) where d(1), d(2), and d(3) are three sizes of particles and n' is an integer having values 0, 1, 2, 3, .... The sols prepared in DMSO were stable against flocculation for months. An unusual solution stability without any capping agents was attributed to the formation of Ag(I)DMSO complex on particle surface, which was confirmed by FTIR, fluorescence spectroscopy, and thermal analysis.
通过在二甲基亚砜（DMSO）中电化学溶解牺牲银电极，合成了无任何封端剂的稳定银纳米颗粒（AgNPs）有机溶胶。紫外可见光谱中在425±5nm处观察到的峰归因于银的表面等离子体共振。通过X射线衍射分析（XRD）证实了银纳米颗粒的形成。在透射电子显微镜（TEM）中，观察到三个粒径范围，即3.75±0.8、6.25±0.5和9.25±0.3nm。基于液滴聚并的新模型解释了这些尺寸之间的相关性。据此，尺寸相关性很好地符合经验公式5d(1)(3)n'+(3 - n')d(2)(3)=d(3)(3)，其中d(1)、d(2)和d(3)是三种颗粒尺寸，n'是取值为0、1、2、3……的整数。在DMSO中制备的溶胶在数月内抗絮凝稳定。没有任何封端剂时溶液具有异常稳定性，这归因于颗粒表面形成了Ag(I)DMSO络合物，通过傅里叶变换红外光谱（FTIR）、荧光光谱和热分析证实了这一点。
