Silver Nanoparticles/Montmorillonite Composites Prepared Using Nitrating Reagent at Water and Glycerol

2008 ◽  
Vol 8 (6) ◽  
pp. 3050-3058 ◽  
Author(s):  
Marta Valášková ◽  
Gražyna Simha Martynková ◽  
Jana Lešková ◽  
Pavla Čapková ◽  
Volker Klemm ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Silver Nitrate ◽  
Interlayer Space ◽  
Exchangeable Cations ◽  
Metallic Silver ◽  
Transmission Electron ◽  
Modeled Structure ◽  
Silicate Layers ◽  
20 Nm ◽  
Nanoparticles Of Silver

Three procedures (P) were applied to prepare silver nanoparticles on natural Ca-montmorillonite (MT). The intercalation of the montmorillonite with silver nitrate in aqueous solution (P1), the intercalation of the montmorillonite with silver nitrate in glycerol (P2) and the successive combination of both P1 and P2methods resulted to P3 method. X-ray powder diffraction (XRD), high-resolution transmission electron microscopy (HRTEM) and Fourier Transform Infrared (FTIR) spectroscopy and the molecular modeling were employed to characterize silver nanoparticles and montmorillonite nanocomposite. The P1 produced MT-1 composite with 2.3 wt% Ag and the partially collapsed layered structure. Nanoparticles of silver larger than 20 nm with a lot of planar defects were randomly distributed on the MT-1 surface; nanoparticles smaller than 20 nm were oriented to the montmorillonite substrate. The MT-2 composite from P2 contained only 1 wt% of Ag. The molecular simulation model of MT-2 showed the interlayer space with the exchangeable cations and metallic silver atoms arrangement within the glycerol bilayer. The P3 produced composite MT-3 that contained 2.4 wt% Ag. The nanoparticles > 20 nm size had a well-defined geometry, very small nanoparticles were amorphous. The modeled structure showed the exchangeable cations, Ag+ and Ag0 located close to the silicate layers and monolayer of glycerol molecules in the interlayer space.

scholarly journals Zirconium Carboxyaminophosphonate Nanosheets as Support for Ag Nanoparticles

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3185
Author(s):  
Morena Nocchetti ◽  
Anna Donnadio ◽  
Eleonora Vischini ◽  
Tamara Posati ◽  
Stefano Ravaioli ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Ag Nanoparticles ◽  
Silver Ions ◽  
Colloidal Dispersion ◽  
Metallic Silver ◽  
Transmission Electron ◽  
Organic Solid ◽  
Bactericidal Properties ◽  
Zinc Cations ◽  
Layered Matrix

A layered insoluble inorganic-organic solid, namely zirconium phosphate glycine-N,N-bismethylphosphonate, was used to prepare dispersions of nanosheets to support active metals such as metallic silver nanoparticles and zinc ions. Zr phosphate-phosphonate microcrystals were first exfoliated with methylamine to produce a stable colloidal dispersion and then the methylamine was removed by treatment with hydrochloric acid. The obtained colloidal dispersion of Zr phosphate-phosphonate nanosheets was used to immobilize silver or zinc cations, via ion exchange, with the acidic protons of the sheets. The layered matrix showed a great affinity for the metal cations up taking all the added cations. The treatment of the dispersions containing silver ions with ethanol yielded metal silver nanoparticles grafted on the surface of the layered host. The samples were characterized by X-ray powder diffraction, elemental analysis transmission electron microscopy, and selected samples were submitted to antimicrobial tests. The nanocomposites based on Ag nanoparticles showed good bactericidal properties against the bacterial reference strain Staphylococcus epidermidis (S. epidermidis).

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.

Preparation of Colloidal Silver Nanoparticles by Laser Ablation; Evaluation and Study on its Developed Applications

2012 ◽  
Vol 488-489 ◽  
pp. 1409-1413
Author(s):  
Adeleh Granmayeh Rad ◽  
Hamed Abbasi
Keyword(s):  
Silver Nanoparticles ◽  
Laser Ablation ◽  
Colloidal Silver ◽  
Laser Ablation Method ◽  
Colloidal Silver Nanoparticles ◽  
Novel Approach ◽  
Transmission Electron ◽  
Good Potential ◽  
Average Size ◽  
20 Nm

In this work we report the preparation of colloidal silver nanoparticles. In order to prepare the silver nanoparticles laser ablation method has been used.A silver coin as a target (purity 99.9 %) was ablated by a Q-Switched Nd:YAG laser with a fluence of about 91 mJ/cm2 at a repetition rate of 10 Hz at room temperature. In order to evaluate these particles transmission electron microscopy (TEM) and spectrophotometry (from UV to NIR) have been used. The average size of prepared nanoparticles is ~ 20 nm. The importance of morphology of nanoparticles has been investigated. Developed applications of silver nanoparticles have been studied,silver nanoparticles are considered as biocompatible and low in toxicity and have good potential for biological applications. Lately silver nanoparticles have found a novel approach in different fields of medicine, biology and industry.

scholarly journals Stachybotrys chartarum: A Novel Biological Agent for The Extracellular Synthesis of Silver Nanoparticles and Their Antimicrobial Activity

2015 ◽  
Vol 18 (2) ◽  
pp. 75 ◽  
Author(s):  
Abdel Ghany Tarek Mohamed
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Silver Nitrate ◽  
Stachybotrys Chartarum ◽  
Capping Agent ◽  
Extracellular Synthesis ◽  
Transmission Electron

Microbial assisted biosynthesis of nanoparticles is a rapidly progressing area of nanobiotechnology. Inthis paper Stachybotrys chartarum assisted extracellular synthesis of silver nanoparticles (AgNPs) is reportedwhen challenged with 1mM silver nitrate (AgNO3). The characterization of AgNPs was carried out visualobservation and UV-Vis spectrophotometry. Further analysis carried out by Fourier Transform InfraredSpectroscopy (FTIR), provides evidence for the presence of proteins as capping agent, which helps in increasingthe stability of the synthesized AgNPs. Transmission Electron Microscopy (TEM) investigations confi rmedthat AgNPs were formed. The synthesized silver nanoparticles were found in the range of 65-108 nm. Finally,the antimicrobial susceptibility of AgNPs synthesized was investigated which exhibited more potent activityagainst bacteria than fungi compared with using silver nitrate at concentration 1mM. Keywords: Antimicrobial activity, Stachybotrys chartarum, Silver nanoparticles

Green Synthesis and Characterization of Silver Nanoparticles by Using Aloe Vera Leaf Extract to Study the Effects of Synthesis Parameters

2016 ◽  
Vol 860 ◽  
pp. 179-184
Author(s):  
Asif Rahman ◽  
A.K.M. Bazlur Rashid ◽  
Md Abdul Aziz Antor ◽  
Md Ashif Anwar ◽  
Roisul Hasan Galib
Keyword(s):  
Silver Nanoparticles ◽  
Silver Nitrate ◽  
Leaf Extract ◽  
Nitrate Solution ◽  
Aloe Vera ◽  
Bath Temperature ◽  
Heating Time ◽  
Water Bath ◽  
Metallic Silver ◽  
Nanoparticle Suspension

In this research silver nanoparticles were synthesized by reducing silver nitrate solution using aloe vera leaf extract as reducing agent. The synthesized nanoparticles had been characterized and the effects of different parameters of synthesis had been evaluated. Silver nanoparticles began to form just after reaction and the whole reduction reaction was completed within 3 hours. The color changed from transparent to dark brown of the aqueous salt solution. Later the nanoparticles were separated out from the mixture by ultra-centrifugation. Here the effects of water bath temperature, the effects of heating time at that certain temperature and the effects of changing concentration of silver nitrate on the size of the synthesized nanoparticles was studied. The particle size and morphology of the synthesized silver nanoparticles were identified by SEM analysis. It was found to be 12-200 nm in different parameters (12-25 nm at the best condition) and spherical in shape. It was also found that the size of silver nanoparticles increased with increasing water bath temperature, increasing heating time and increasing silver nitrate concentration. Energy dispersive X-ray spectroscopy was used to confirm that the nanoparticle suspension contains nothing but metallic silver. It was found that 70% of elemental silver nanoparticles were present.

scholarly journals Biosynthesis of Silver Nanoparticles by Aspergillus terreus: Characterization, Optimization, and Biological Activities

2021 ◽  
Vol 9 ◽  
Author(s):  
Walid A. Lotfy ◽  
Basma M. Alkersh ◽  
Soraya A. Sabry ◽  
Hanan A. Ghozlan
Keyword(s):  
Silver Nanoparticles ◽  
Aspergillus Terreus ◽  
Inhibitory Concentration ◽  
Biological Activities ◽  
Antagonistic Activity ◽  
Metallic Silver ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

In this study, mycelial filtrate of Aspergillus terreus BA6 was used to reduce AgNO3 to form silver nanoparticles (AgNPs). The effect of seven independent variables on the diameter of AgNPs was studied by applying design of experiments (DOE). At optimal conditions, the diameter of AgNPs was reduced by approximately 26.7% compared to the basal culture condition and AgNO3 concentration was found to be the most significant factor affecting the diameter of AgNPs. A. terreus nano-Ag was characterized using UV-visible spectroscopy, transmission electron microscopy, energy dispersive X-ray (EDX), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Zeta potential. The maximum UV absorption was obtained at 420 nm and the microscopic results showed particles with narrow size distribution ranging from 7 to 23 nm. XRD pattern of AgNPs revealed four diffraction peaks of metallic silver and the EDX spectrum showed a strong signal attributed to Ag nano-crystals. AgNPs mycofabricated by A. terreus showed potent minimum inhibitory concentration (MIC) and broad minimum bactericidal/fungicidal concentration (MBC/MFC) against 12 reference microorganisms. The MIC and MBC/MFC values of AgNPs were 0.312 to 1.25 μg/ml and 0.625 to 10 μg/ml, respectively. Nevertheless, AgNPs did not demonstrate any antagonistic activity against Coxsackie B virus. The in vitro cytotoxicity of the mycosynthesized AgNPs showed significant antitumor activity against adenocarcinoma epithelial cells from human breast cancer (Mcf-7) cell line with an inhibitory concentration (IC50) of 87.5 μg/ml.

scholarly journals A New Method for the Deposition of Metallic Silver on Porous Ceramic Water Filters

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Kathryn N. Jackson ◽  
James A. Smith
Keyword(s):  
Silver Nanoparticles ◽  
Silver Nitrate ◽  
Removal Rate ◽  
Aqueous Suspension ◽  
Porous Ceramic ◽  
New Method ◽  
Metallic Silver ◽  
E Coli ◽  
Filter Performance ◽  
Continuous Feed

A new method of silver application to a porous ceramic water filter used for point-of-use water treatment is developed. We evaluated filter performance for filters manufactured by the conventional method of painting an aqueous suspension of silver nanoparticles onto the filter and filters manufactured with a new method that applies silver nitrate to the clay-water-sawdust mixture prior to pressing and firing the filter. Filters were evaluated using miscible displacement flow-through experiments with pulse and continuous-feed injections of E. coli. Flow characteristics were quantified by tracer experiments using [3H]H2O. Experiments using pulse injections of E. coli showed similar performance in breakthrough curves between the two application methods. Long-term challenge tests performed with a continuous feed of E. coli and growth medium resulted in similar log removal rates, but the removal rate by nanosilver filters decreased over time. Silver nitrate filters provided consistent removal with lower silver levels in the effluent and effective bacterial disinfection. Results from continued use with synthetic groundwater over 4 weeks, with a pulse injection of E. coli at 2 and 4 weeks, support similar conclusions—nanosilver filters perform better initially, but after 4 weeks of use, nanosilver filters suffer larger decreases in performance. Results show that including silver nitrate in the mixing step may effectively reduce costs, improve silver retention in the filter, increase effective lifespan, and maintain effective pathogen removal while also eliminating the risk of exposure to inhalation of silver nanoparticles by workers in developing-world filter production facilities.

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.

Biosynthesis of Silver Nanoparticles from Eucalyptus corymbia Leaf Extract at Optimized Conditions

2019 ◽  
Vol 25 ◽  
pp. 32-45 ◽  
Author(s):  
Munyao Joshua Sila ◽  
Michira Immaculate Nyambura ◽  
Deborah Atieno Abong’o ◽  
Francis B. Mwaura ◽  
Emmanuel Iwuoha
Keyword(s):  
Silver Nanoparticles ◽  
Plant Extract ◽  
Narrow Range ◽  
Visible Spectrum ◽  
Extraction Temperature ◽  
Transmission Electron ◽  
Uv Visible ◽  
Silver Nitrate Concentration ◽  
The Fourier Transform ◽  
20 Nm

This study reports the biosynthesis of narrow range diameter silver nanoparticles at optimum conditions usingEucalyptus corymbiaas a reducing and stabilizing agent. Optimal conditions for biosynthesis of silver nanoparticles (AgNPs) were found to be; an extraction temperature of 90°C, pH of 5.7 a Silver Nitrate concentration of 1mM and AgNO3to plant extract ratio of 4:1. UV-Visible spectroscopy monitored the formation of colloidal AgNPs. The UV-Visible spectrum showed a peak around 425 nm corresponding to the Plasmon absorbance of the AgNPs. The size and shape characterization of the AgNPs was done using Transmission Electron Microscopy (TEM) techniques which revealed narrow range diameter (18-20 nm), almost monodispersed AgNPs, spherical in nature and with minimal agglomeration. Energy Dispersive X-ray (EDX) results showed the presence of two peaks at 3.0 and 3.15 keV in the silver region. The Fourier Transform Infrared-Spectra (FTIR) of the plant extract and the AgNPs gave rise to vibrational peaks at 3260 and 1634 wavenumbers which are due to the presence of OH and –C=C-functional groups respectively.

Green Synthesis of Silver Nanoparticles Using Prunus Amygdalus Extract and their Anti-Microbial Activity

2015 ◽  
Vol 1119 ◽  
pp. 165-169
Author(s):  
S.K. Srikar ◽  
D.D. Giri ◽  
C. Upadhyay ◽  
P.K. Mishra ◽  
S.N. Upadhyay
Keyword(s):  
Silver Nanoparticles ◽  
Silver Nitrate ◽  
Single Step ◽  
Prunus Amygdalus ◽  
E Coli ◽  
Bacteriostatic Property ◽  
Silver Nitrate Concentration ◽  
Average Size ◽  
20 Nm ◽  
Sun Light

Highly stable silver nanoparticles synthesized in single-step green method by mixing silver nitrate and aqueous extract of Almond (Prunus amygdalus). Experiments were conducted to influence the change in the silver nitrate concentration and time on the synthesis of silver nanoparticles at room temperature under dispersed sun light. The almond extract acted both as the reducing and stabilizing agent for the synthesis of silver nanoparticles. The change in the color of the reaction mixture was monitored using UV-Visible spectrometry whereas particles synthesized were characterized using Scanning Electron Microscopy, Dynamic Light Scattering and Fourier Transform Infrared Spectroscopy. The synthesized nanoparticles were almost spherical in shape with an average size about 20 nm and they exhibited bacteriostatic property against E. coli.

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