Papers by Keyword: Silver Nanostructure

Abstract: We demonstrated the fabrication of the flower-like silver nanoplate micro-assemblies in high yields by a facile hydrothermal method. This novel nanostructure was synthesized in the presence of poly (vinyl pyrrolidone) (PVP) and ascorbic acid (AsA) at 150 °C for 10 h. The microassemblies with average size of 1~2 μm are consisted of several uniform nanoplates and show face centered cubic structure. The effects of the concentration of reactants, molar ratio of silver nitrate to ascorbic acid on the formation of the flower-like silver micro-assemblies were also presented.

Abstract: Microwave irradiation is a novel method to accelerate the preparation of inorganic nanoparticles as well as various nanostructures such as nanotubes, nanorods, and nanowires. In this research, silver (Ag) nanostructures with various morphologies were prepared via a rapid microwave-assisted technique. The spherical and polygonal Ag nanoparticles were synthesized in the presence of Polyvinilpyroliden (PVP) as stabilizing agent. Ethylene glycol (EG) serves as a solvent. The silver nanoparticles were produced by Continuous and Discontinuous Wave irradiation. The obtained materials were characterized by UV-visible and transmission electron microscopy (TEM). The results present that the size of nanoparticles increase in continuous irradiation. In this process, the morphology of product is polygonal. In the discontinuous process the colloidal particle size is smaller than that obtained from the continuous process. Furthermore, the Ag nanoparticles have spherical shapes. The final data show that microwave processing has unique advantages over conventional heating processes.

Abstract: We described a facile approach to controllably synthesize silver nanoparticles with various morphologies using N, N-dimethylformamide (DMF) in the presence of poly (vinyl pyrrolidone) (PVP). Triangular/hexagonal nanoplates, chain-like nanoplate assemblies, and nanobelts could be selectively obtained. On the basis of the experimental results, the concentration of poly (vinyl pyrrolidone) and AgNO3, reactive temperature and time were the vital factors to determine the shape of final products. Reasonable mechanisms for the formation of silver nanoparticles with various morphologies were proposed. Fluorescence modulation of dye rhodamine B (RhB) and fluorescein (FI) in the presence of silver nanoparticles were studied. Addition of silver nanoparticles could produce fluorescence enhancement and show self-quenching release of RhB, while the fluorescence intensity of FI decreased due to the presence of the silver nanoparticles. The effects of silver nanoparticles on the fluorescence properties of dyes were dependent on the competition between the local field enhancement and non-radiation energy transfer from the molecule to the metallic nanoparticles.