scholarly journals Preparation of silver nanoparticles by gamma Irradiation method using chitosan as stabilizer

2014 ◽  
Vol 4 (3) ◽  
pp. 43-46
Author(s):  
Tan Man Nguyen ◽  
Hai Le ◽  
Huu Tu Le ◽  
Thu Hong Tran ◽  
Duy Hang Nguyen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Storage Time ◽  
Average Diameter ◽  
Colloidal Silver ◽  
Surface Plasma ◽  
Surface Plasma Resonance ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Γ Ray

Silver nanoparticles were prepared from (Ag+) aqueous solution by the method of γ-ray irradiation using chitosan as stabilizer. The saturated conversion dose (Ag+ à Ago) determined by UV-Vis spectroscopy was found to be about 16 kGy. The UV-Vis spectrum showed that an absorption peak at λmax = 400 nm due to surface plasma resonance. The image of transmission electron microscopy (TEM) showed that the silver nanoparticles were mostly spherical in shape and the average diameter was of about ~ 12 nm. The prepared colloidal silver nanoparticles solution was in good stability during storage time.

Effect of Laser Fluence on Siliver Nanoparticles Colloid

2011 ◽  
Vol 415-417 ◽  
pp. 747-750
Author(s):  
Bing Xu ◽  
Ren Guo Song ◽  
Chao Wang
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Laser Ablation ◽  
Laser Fluence ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Average Diameter ◽  
Distilled Water ◽  
Transmission Electron ◽  
Silver Target

In order to study the effects of laser fluence on silver nanoparticles colloid, the silver nanoparticles colloid was prepared by pulsed laser ablation of silver target for 10min in distilled water at different laser fluence. The particles size，morphologies and absorption spectroscopy of the obtained nanoparticles colloid were characterized by ultraviolet to visible (UV-Vis) spectrometer and transmission electron microscopy (TEM), the average diameter and its distribution were analyzed by Image-ProPlus software. The results shown that the average diameter of the silver nanoparticles prepared at the laser fluence of 4.2J/cm2 was the smallest (D=17.54nm), also, the distribution of particle size was narrowest (=36.86nm) and the morphologies were more homogeneous. It was confirmed that the nanoparticles size and shape could be controlled by pulsed laser ablation parameters.

The Aggregation Study and Characterization of Silver Nanoparticles

2017 ◽  
Vol 263 ◽  
pp. 165-169
Author(s):  
Silvia Chowdhury ◽  
Faridah Yusof ◽  
Nadzril Sulaiman ◽  
Mohammad Omer Faruck
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Silver Nanoparticles ◽  
Absorption Spectrum ◽  
Average Particle Size ◽  
Average Particle ◽  
Transmission Electron ◽  
Vis Spectroscopy

In this article, we have studied the process of silver nanoparticles (AgNPs) aggregation and to stop aggregation 0.3% Polyvinylpyrrolidone (PVP) was used. Aggregation study carried out via UV-vis spectroscopy and it is reported that the absorption spectrum of spherical silver nanoparticles were found a maximum peak at 420 nm wavelength. Furthermore, Transmission Electron Microscopy (TEM) were used to characterized the size and shape of AgNPs, where the average particle size is around 10 to 25 nm in diameter and the AgNPs shape is spherical. Next, Dynamic Light Scattering (DLS) were used, owing to observed size distribution and self-correlation of AgNPs.

scholarly journals Fortunella japonica extract as a reducing agent for green synthesis of silver nanoparticles

2018 ◽  
Vol 7 (3) ◽  
pp. 1570
Author(s):  
Nguyen Phung Anh ◽  
Truong Thi Ai Mi ◽  
Duong Huynh Thanh Linh ◽  
Nguyen Thi Thuy Van ◽  
Hoang Tien Cuong ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Volume Ratio ◽  
Diffusion Method ◽  
High Antibacterial Activity ◽  
Agno3 Solution ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Average Size

A rapid way of synthesizing silver nanoparticles (AgNPs) by treating Ag+ ions with a green Fortunella Japonica (F.J.) extract as a combined reducing and stabilizing agent was investigated. The reaction solutions were monitored using UV-Vis spectroscopy, the size and shape of crystals were determined by scanning electron microscopy and transmission electron microscopy, the crystalline phases of AgNPs were presented by X–ray diffraction, and the relation of nanoparticles with Fortunella Japonica extract was confirmed using fourier transform infrared spectroscopy. The results indicated that no formation of AgNPs had taken place in the dark during 24 hours at room temperature and 40 oC. Meanwhile, it was found that the rate of AgNPs formation increased rapidly under the sunlight. The effects of the synthesis factors on the AgNPs formation were investigated. The suitable conditions for the synthesis of AgNPs using F.J. extract were determined as follows: F.J. extract was mixed with AgNO3 1.75 mM solution with the volume ratio of 3.5 AgNO3 solution/1.5 F.J. Extract, stirred 300 rpm for 150 minutes at 40 oC under sunlight illumination. At these conditions, AgNPs showed high crystalline structure with the average size of 15.9 nm. The antibacterial activity of silver nanoparticles was determined by agar well diffusion method against E. coli and B. subtilis bacteria. The green synthesized AgNPs performed high antibacterial activity against both bacteria.  

Fabrication and Characterization of Cellulose Acetate Ultrafine Fiber Containing Silver Nanoparticles by Electrospinning

2011 ◽  
Vol 337 ◽  
pp. 116-119 ◽  
Author(s):  
Dong Mei Zhao ◽  
Qing Mao Feng ◽  
Li Li Lv ◽  
Jian Li
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Cellulose Acetate ◽  
Average Diameter ◽  
Xrd Analysis ◽  
Water Soluble ◽  
Ag Nps ◽  
Ultrafine Fibers ◽  
Transmission Electron ◽  
Electrospinning Method

Silver nanoparticles (Ag NPs)/cellulose acetate (CA) composite ultrafine fibers were successfully prepared by the electrospinning method. Water-soluble Ag NPs were directly mixed into CA polymer fibers to form organic–inorganic composite ultrafine fibers. The optical property of Ag NPs was measured by ultraviolet-visble spectrometer (UV-vis). The presence and identification of crystalline of Ag NPs were confirmed by XRD analysis. Transmission electron microscopy (TEM) images showed that silver nanoparticles (Ag NPs) with an average diameter of 5–15 nm were obtained and were well distributed in the CA ultrafine fibers. The morphologies of the as-prepared electrospun Ag NPs/CA composite ultrafine fibers were characterized by scanning electron microscopy (SEM) and TEM. The composition of fibers was characterized by FTIR spectrometer.

scholarly journals Extracellular Biofabrication, Characterization, and Antimicrobial Efficacy of Silver Nanoparticles Loaded on Cotton Fabrics Using Newly IsolatedStreptomycessp. SSHH-1E

2016 ◽  
Vol 2016 ◽  
pp. 1-17 ◽  
Author(s):  
Noura El-Ahmady El-Naggar ◽  
Attiya Mohamedin ◽  
Sarah Shawqi Hamza ◽  
Abdel-Dayem Sherief
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silver Nanoparticles ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Fourier Transform Infrared Spectroscopy ◽  
Fourier Transform Infrared ◽  
Cell Free Supernatant ◽  
Transmission Electron ◽  
Vis Spectroscopy

Biological method for silver nanoparticles synthesis has been developed to obtain cost effective, clean, nontoxic, and ecofriendly size-controlled nanoparticles. The objective of this study is extracellular biosynthesis of antimicrobial AgNPs using cell-free supernatant of a localStreptomycessp. strain SSHH-1E. Different medium composition and fermentation conditions were screened for maximal AgNPs biosynthesis using Plackett-Burman experimental design and the variables with statistically significant effects were selected to study their combined effects and to find out the optimum values using a Box-Behnken design. The synthesized AgNPs were characterized using UV-visible spectroscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and energy dispersive X-ray spectroscopy. Rapid biosynthesis of AgNPs was achieved by addition of 1 mM AgNO3solution to the cell-free supernatant. The produced particles showed a single surface plasmon resonance peak at 400 nm by UV-Vis spectroscopy which confirmed the presence of AgNPs.Streptomycessp. SSHH-1E was identified asStreptomyces narbonensisSSHH-1E. Transmission electron microscopy study indicated that the shape of AgNPs is spherical and the size is ranging from 20 to 40 nm. Fourier transform infrared spectroscopy analysis provides evidence for proteins as possible reducing and capping agents. Furthermore, the biosynthesized AgNPs significantly inhibited the growth of medically important pathogenic Gram-positive and Gram-negative bacteria and yeast. The maximum biosynthesis of AgNPs was achieved at initial pH of 8, peptone of 0.5 g, and inoculum age of 48 h. The statistical optimization resulted in a 4.5-fold increase in the production of AgNPs byStreptomyces narbonensisSSHH-1E.

scholarly journals One pot synthesis of silver nanoparticles using a cyclodextrin containing polymer as reductant and stabilizer

2014 ◽  
Vol 5 ◽  
pp. 380-385 ◽  
Author(s):  
Arkadius Maciollek ◽  
Helmut Ritter
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silver Nanoparticles ◽  
Optical Properties ◽  
Silver Nitrate ◽  
Room Temperature ◽  
One Pot ◽  
One Pot Synthesis ◽  
Transmission Electron ◽  
Vis Spectroscopy

A facile and one pot synthesis of silver nanoparticles with narrow size distributions using silver nitrate and a copolymer 1 from N-isopropylacrylamide (NIPAM) and mono-(1H-triazolylmethyl)-2-methylacryl-β-cyclodextrin acting as reductant and stabilizer without using any additional reducing agent is reported. The reduction was carried out in aqueous solution under pH neutral conditions at room temperature. The results of dynamic light scattering analysis and transmission electron microscopy show adjustable particle sizes from 30–100 nm, due to variation of silver nitrate concentration, the polymeric reducing and stabilisation agent concentration or reaction time. The spherical structure of the silver nanoparticles has been confirmed by UV–vis spectroscopy and transmission electron microscopy. The optical properties of the nanoparticles have also been characterized by fluorescence spectroscopy. The formed spherical particles are stable in aqueous medium at room temperature over a period of several weeks. Furthermore the changes in the optical properties of the nanoparticles due to thermo induced volume phase transition behavior of the thermoresponsive cyclodextrin containing polymer 1 have been characterized by UV–vis spectroscopy.

scholarly journals Phytochemical Synthesis and Preliminary Characterization of Silver Nanoparticles Using Hesperidin

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Anish Stephen ◽  
Sankar Seethalakshmi
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Transmission Electron Microscopy ◽  
Silver Nanoparticles ◽  
Reaction Time ◽  
Silver Nanoparticle ◽  
Size Range ◽  
Transmission Electron ◽  
Vis Spectroscopy

This paper is the first of its kind for development of rapid and ecofriendly method for synthesis of silver nanoparticles from aqueous solution of silver nitrate using the flavonoid “hesperidin” and optimization of the methodology. There is formation of stable spherical silver nanoparticles in the size range of 20–40 nm. Optimization of methodology in terms of concentration of reactants and pH of the reaction mixture reduced the reaction time for silver nanoparticle formation to 2 mins. Silver nanoparticles (AgNPs) were characterized by UV-Vis spectroscopy and transmission electron microscopy (TEM). UV-vis spectroscopy derived spectrum demonstrated a peak of 430 nm which corresponds to the plasmon absorbance of silver nanoparticles. Transmission electron microscopy revealed spherical shaped silver nanoparticles in the size range of 20–40 nm.

scholarly journals Biosynthesis, characterisation and therapeutic applications of plant-mediated silver nanoparticles

2018 ◽  
Vol 83 (5) ◽  
pp. 515-538 ◽  
Author(s):  
Andreia Corciova ◽  
Bianca Ivanescu
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Nanoparticle Synthesis ◽  
Special Importance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Stabilizing Agents ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Nanoparticles Synthesis

Nanotechnology is one of the most studied domains, and nanoparticle synthesis, especially of silver nanoparticles, has gained special importance due to their properties, biocompatibility and applications. Today, the processes of nanoparticles synthesis tend toward the development of inexpensive, simple, non-toxic and environmentally friendly methods. Thus, the use of plants in the synthesis of silver nanoparticles has attracted considerable interest because biomolecules can act as both reducing and stabilizing agents. This survey aims at discussing the conditions for obtaining silver nanoparticles using plants and their characterization by several methods, such as FTIR and UV?Vis spectroscopy, X-ray diffraction, and scanning and transmission electron microscopy. In addition, it examines some of the most common biological uses of silver nanoparticles: antibacterial, antioxidant and cytotoxic.

scholarly journals Physical Characteristics of Titania Nanofibers Synthesized by Sol-Gel and Electrospinning Techniques

2010 ◽  
Vol 5 (1) ◽  
pp. 155892501000500 ◽  
Author(s):  
Soo-Jin Park ◽  
Yong C. Kang ◽  
Ju Y. Park ◽  
Ed A. Evans ◽  
Rex D. Ramsier ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Average Diameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Ceramic Nanofibers ◽  
Titania Nanofibers

Titania nanofibers were successfully synthesized by sol-gel coating of electrospun polymer nanofibers followed by calcining to form either the pure anatase or rutile phases. Characterization of these materials was carried out using scanning electron microscopy (SEM), transmission electron microscopy (TEM), diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV-vis spectroscopy techniques. The average diameter of these ceramic nanofibers was observed to be around 200 nm for both the rutile and anatase forms. The valence band structure and optical absorption thresholds differ, however, indicating that nanofibrous mats of titania can be selectively developed for different applications in catalysis and photochemistry.

scholarly journals Biocide Activity of Green Quercetin-Mediated Synthesized Silver Nanoparticles

Nanomaterials ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 909 ◽  
Author(s):  
Federico Tasca ◽  
Riccarda Antiochia
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Room Temperature ◽  
Inhibitory Concentration ◽  
Toxic Chemicals ◽  
Candida Sp ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
20 Nm ◽  
Mic Value

The development of new nanomaterials is gaining increasing attention due to their extensive applications in fields ranging from medicine to food and cultural heritage. Green nanoparticles provide advantages compared to conventional nanoparticles as their synthesis is environmentally-friendly and does not require the use of high temperatures, pressure, or toxic chemicals. In this paper, green silver nanoparticles (AgNPs) have been synthesized according to a new method using quercetin as a reducing agent at room temperature. The synthesized AgNPs were characterized using UV-Vis spectroscopy, transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), and dynamic light scattering (DLS) techniques and successively tested for biocide activity by studying their effects in the inhibition of bacterial growth. The results demonstrated that the smaller the AgNPs size, the greater their biocide activity. In particular, AgNPs with a diameter of 8 nm showed a minimum inhibitory concentration (MIC) value of 1.0 μg/mL against Streptococcus sp., Escherichia coli and Candida sp. microorganisms, while AgNPs with a larger diameter of about 20 nm were able to inhibit microbial of all selected pathogens at a higher MIC value of 2.5 μg/mL.

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