Influence of Water on Room-Temperature Preparation of Silver Nanoparticles Using Poly(vinyl pyrrolidone) as Reducing Agent

2013 ◽  
Vol 13 (6) ◽  
pp. 4084-4089 ◽  
Author(s):  
Dan Wu ◽  
Wei Wang ◽  
Fatang Tan ◽  
Huixin Zhang ◽  
Xiaolin Qiu ◽  
...  
2012 ◽  
Vol 268-270 ◽  
pp. 580-583 ◽  
Author(s):  
Yong Tang Jia ◽  
Cui Wu ◽  
Feng Chun Dong ◽  
Gang Huang ◽  
Xian Hua Zeng

The composite nanofiber membranes of poly (ε-caprolactone)/poly(vinyl pyrrolidone) (PCL/PVP) containing silver nanoparticles were prepared by electrospinning method. The morphology of composite nanofibers was characterized by scanning electron microscopy (SEM). The silver nanoparticles on the electrospun fibers were characterized by X-Ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The contact angle and water uptake of PCL/PVP/Ag nanofiber membranes were measured. The SEM photos indicated that the average diameter of the fibers was significantly decreased with the addition of silver nanoparticles. The X-Ray images showed that Ag nanoparticles were distributed on the surface of nanofiber membranes. When the PVP mole ratio was higher than 15%, the nanofiber membranes showed good hydrophilic property. The PCL/PVP/Ag nanofiber membranes could be applied to prepare wound dressing.


Coatings ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 288 ◽  
Author(s):  
Marco Zannotti ◽  
Andrea Rossi ◽  
Rita Giovannetti

In this work, we prepared different morphologies of silver nanoparticles: nanosphere, triangular nanoplates, hexagonal nanoplates, and quasi-spherical shapes, through one-step synthesis. Hydrogen peroxide was used as the oxidizing agent during the reduction of silver nitrate by sodium borohydride, in the presence of tri-sodium citrate and poly-vinyl-pyrrolidone. The obtained silver nanoparticles were fully characterized by UV-Vis spectroscopy, Dynamic Light Scattering and Scanning Electron Microscopy, and successfully used as Surface Enhanced Raman Scattering (SERS) substrates. The effect of shape and morphology on the Raman scattering enhancement was evaluated by using methylene blue as target molecules. The Raman measurements demonstrated that the prepared substrates are reliable and sensitive with analytical enhancement factors, estimated to be around 105 with a concentration of methylene blue 1 μM. When triangular and hexagonal nanoplates were tested with different concentrations of analyte, they demonstrated a good linearity in Raman intensity with a good detection of methylene blue 0.1 μM.


2017 ◽  
Vol 727 ◽  
pp. 514-518
Author(s):  
Chun Gu ◽  
Guo Qiang Luo ◽  
Rui Zhi Zhang ◽  
Jian Zhang ◽  
Yuan Li ◽  
...  

In this work, monodispersed silver nanoparticles with controllable size have been successfully in situ synthesized in PMMA matrix. NaHS, HCl and poly (vinyl pyrrolidone) (PVP) were used to optimize the nucleation and growth of silver nanocrystalline. UV–vis analysis and transmission electron microscopy (TEM) were used to characterize the size and dispersion of silver nanoparticles in the Ag/PMMA nanocomposites. The results show that silver nanoparticles homogeneously distribute in PMMA/DMF sol and the particle size of silver nanoparticles increase with the increasing of time. The nucleation of Ag atoms can be facilitated through the addition of a trace amount of NaHS to generate Ag2S clusters as heterogeneous nuclei. Introducing a trace amount of Cl- into the reaction system can effectively reduce the growth rate of the nanoparticles and thus generating more uniform silver nanoparticles in PMMA matrix.


Nanoscale ◽  
2015 ◽  
Vol 7 (37) ◽  
pp. 15197-15208 ◽  
Author(s):  
Shilpi Ghosh ◽  
Shankha S. Acharyya ◽  
Malika Kumar ◽  
Rajaram Bal

A halide ion promoted 2D silver tungsten-based nanoarchitecture, synthesized by a facile synthesis protocol, exhibited high catalytic performance for the production of a wide range of N-oxides.


2015 ◽  
Vol 3 (45) ◽  
pp. 11833-11841 ◽  
Author(s):  
Xiaojun Sun ◽  
Dong Qin

We report a new strategy for the synthesis of Ag@Ag–Au core–frame nanocubes by co-titrating AgNO3 and HAuCl4 concomitantly into an aqueous suspension of Ag nanocubes in the presence of ascorbic acid (AA) and poly(vinyl pyrrolidone) at room temperature.


2008 ◽  
Vol 47-50 ◽  
pp. 920-923 ◽  
Author(s):  
Xin He ◽  
Xiu Jian Zhao ◽  
Jin Yang Feng ◽  
Xiao Tao Sui

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.


2014 ◽  
Vol 1015 ◽  
pp. 480-483
Author(s):  
Men Wu ◽  
Dong Sheng Wang

Silk sericin is used as a biotemplate to redox silver nanoparticles in situ at room temperature. Silk sericin provides multiple functions in the whole reaction system, serving as the reducing agent of Ag+, and the dispersing and stabilizing agent of the resulted silver nanoparticles. The effect of the concentration of sericin on size and shape of the reduced silver nanoparticles is studied. UV-vis spectra and TEM are used to detected the characteristic plasmon and the appearance of the obtained silver nanoparticles.


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