Investigation of Morphology and Structure of Poly(ethylene glycol)-Coated Silver Nanowires by Electron Microscopy: Investigation of Morphology and Structure of Poly(ethylene glycol)-Coated Silver Nanowires by Electron Microscopy

• Published in: Fēnxī huàxué 2010-02, Vol.38 (2), p.149-152
• Main Authors: HUANG, Li-Jian, WANG, Er-Kang
• Format: Article
• Language: English
• Subjects: Capping; Electron diffraction; Electron microscopy; Ethylene glycol; Morphology; Nanoparticles; Nanorods; Nanowires; Scanning electron microscopy; Silver; Transformations; Transmission electron microscopy
• ISSN: 0253-3820
• DOI: 10.3724/SP.J.1096.2010.00149

Poly (ethylene glycol) (PEG) coated silver nanowires has been hydrothermally prepared at a very slow rate, in which PEG was used as both a mild capping agent and a weak reductant. As-prepared silver nanowires (SNWs) have been characterized using scanning electron microscopy and transmission electron microscope, which showed that the SNWs are usually longer than 100 mu m and their diameters (each SNW has a uniform thickness) vary mainly in the range of 80~300 nm. Surprisingly, some of these silver nanowires connected by their two ends to form some close-looped silver nanowires, which hitherto has not been reported elsewhere. The existence of close-looped silver nanowires supports the mechanism that nanowires can evolve from fusion of some nanoparticles and/or shorter nanorods. Careful TEM characterization and selected area electron diffraction revealed that the silver nanowires kept a five-fold twinned structure, which is opposite to some reports that a long-time incubation will lead to the disappearance of this twin structure. This work demonstrates the situation that deeper investigation is still needed for understanding the structure transformation of silver nanowires.