Silver Trees: Chemistry on a TEM Grid

2009 ◽  
Vol 62 (3) ◽  
pp. 260 ◽  
Author(s):  
Mallikarjuna N. Nadagouda ◽  
Rajender S. Varma
Keyword(s):  
Room Temperature ◽  
Nitrate Solution ◽  
Silver Nitrate Solution ◽  
Carbon Substrate ◽  
Temperature Synthesis ◽  
Antimicrobial Coatings ◽  
Transmission Electron ◽  
Technological Potential ◽  
Silver Dendrites ◽  
Tem Grid

The copper–carbon substrate of a transmission electron microscopy (TEM) grid reacted with aqueous silver nitrate solution within minutes to yield spectacular tree-like silver dendrites, without using any added capping or reducing reagents. These results demonstrate a facile, aqueous, room-temperature synthesis of a range of noble metal nano- and meso-structures that have widespread technological potential in the design and development of next-generation fuel cells, catalysts, and antimicrobial coatings.

scholarly journals Antimicrobial Bacterial Cellulose-Silver Nanoparticles Composite Membranes

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Hernane S. Barud ◽  
Thaís Regiani ◽  
Rodrigo F. C. Marques ◽  
Wilton R. Lustri ◽  
Younes Messaddeq ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Bacterial Cellulose ◽  
Nitrate Solution ◽  
Composite Membranes ◽  
Silver Nitrate Solution ◽  
Complexing Agent ◽  
X Ray Diffraction ◽  
Gram Positive Bacteria ◽  
Transmission Electron

Antimicrobial bacterial cellulose-silver nanoparticles composite membranes have been obtained by“in situ”preparation of Ag nanoparticles from hydrolytic decomposition of silver nitrate solution using triethanolamine as reducing and complexing agent. The formation of silver nanoparticles was evidenced by the X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and absorption in the UV-Visible (350 nm to 600 nm). Thermal and mechanical properties together with swelling behavior for water were considered. TEA concentration was observed to be important in order to obtain only Ag particles and not a mixture of silver oxides. It was also observed to control particle size and amount of silver contents in bacterial cellulose. The composite membranes exhibited strong antimicrobial activity against Gram-negative and Gram-positive bacteria.

Pretreated Lignocellulosic Waste Mediated Biosynthesis of Silver Nanoparticles Under Room Temperature

2016 ◽  
Vol 15 (05n06) ◽  
pp. 1660001 ◽  
Author(s):  
V. P. Manjamadha ◽  
Karuppan Muthukumar
Keyword(s):  
Silver Nanoparticles ◽  
Silver Nitrate ◽  
Room Temperature ◽  
Nitrate Solution ◽  
Silver Ions ◽  
Silver Nitrate Solution ◽  
Morphological Characterization ◽  
Alternative Source ◽  
X Ray ◽  
Antibacterial Performance

The current work elucidates the utilization of biowaste as a valuable reducing agent for the synthesis of silver nanoparticles. In this study, the wastewater generated during the alkaline pretreatment of lignocellulosic wastes (APLW) was used as a bioreductant to reduce silver nitrate under room temperature. Synthesis of stable silver nanoparticles (AgNPs) was achieved rapidly on addition of APLW into the silver nitrate solution (1[Formula: see text]mM). The morphological characterization of AgNPs was performed using field emission scanning electron microscopy (FESEM). The micrograph clearly depicted the presence of spherical AgNPs. The presence of elemental silver along with biomoilties was determined using energy dispersive X-ray spectroscopy (EDAX) analysis. The X-ray diffraction (XRD) study proved the crystalline form of stable AgNPs. The AgNPs exhibited excellent antibacterial performance against Gram negative organism. The immediate bioreduction of silver ions using APLW was well illustrated in the present study. Thus, APLW serve as an alternative source for reducing agents instead of utilizing valuable medicinal plants for nanoparticles synthesis.

Formation Mechanism and Microwave Permittivity of Carbon Nanotubes Filled with Metallic Silver Nanowires

2007 ◽  
Vol 334-335 ◽  
pp. 685-688
Author(s):  
Dong Lin Zhao ◽  
Xia Li ◽  
Wei Dong Chi ◽  
Zeng Min Shen
Keyword(s):  
Carbon Nanotubes ◽  
Formation Mechanism ◽  
Silver Nanowires ◽  
Nitrate Solution ◽  
Silver Nitrate Solution ◽  
Metallic Silver ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Microwave Permittivity

The filling of multi-walled carbon nanotubes (MWNTs) with metallic silver nanowires via wet chemistry method was investigated. The carbon nanotubes were filled with long continuous silver nanowires. The carbon nanotubes were almost opened and cut after being treated with concentrated nitric acid. Silver nitrate solution filled carbon nanotubes by capillarity. Carbon nanotubes were filled with silver nanowires after calcinations by hydrogen. The diameters of silver nanowires were in the range of 20-40nm, and lengths of 100nm-10μm. We studied the micromorphology of the silver nanowires filled in carbon nanotubes by transmission electron microscopy (TEM) and X-ray diffraction (XRD). Based on the experimental results, a formation mechanism of the Ag nanowire-filled carbon nanotubes was proposed. And the microwave permittivity of the carbon nanotubes filled with metallic silver nanowires was measured in the frequency range from 2 GHz to 18 GHz. The loss tangent of the carbon nanotubes filled with metallic silver nanowires is high. So the carbon nanotubes filled with metallic silver nanowires would be a good candidate for microwave absorbent.

A Facile, “Green” One – Step, Room Temperature Synthesis of a Series of monodispersed MSe(M = Cd or Zn) Water Dispersible Nanoparticles

2008 ◽  
Vol 1138 ◽  
Author(s):  
Oluwatobi S. Oluwafemi ◽  
Neerish Revaprasadu
Keyword(s):  
Room Temperature ◽  
Metal Salt ◽  
Water Soluble ◽  
Synthetic Approach ◽  
Temperature Synthesis ◽  
Water Dispersible ◽  
Aspect Ratios ◽  
Transmission Electron ◽  
One Step ◽  
Capping Ligands

AbstractWe herein report a facile, ‘green’ one- step synthesis of a series of monodispersed water-soluble selenide nanoparticles at room temperature. The capping ligands used include, cysteine, methionine, ascorbic acid and starch which function as agents of solubilisation, stabilization and conjugation sites for biomolecules. The synthetic approach involves the addition of an appropriate volume of selenide ion produced via the reduction of selenium powder in water to an aqueous solution containing the ligand- metal salt (MCl2 M = Zn or Cd). Optical spectroscopy shows that the particles are of high quality while the transmission electron microscopy (TEM) of the samples shows variation in shapes ranging from dots to rods of high and low aspect ratios.

Effect of nanosilver on the thermal stability and thermal decomposition kinetics of poly(acetoacetoxyethyl methacrylate–styrene)

2018 ◽  
Vol 50 (8) ◽  
pp. 710-719
Author(s):  
Shengtao Gao ◽  
Honglong Xing
Keyword(s):  
Thermal Stability ◽  
Degradation Kinetics ◽  
Nitrate Solution ◽  
Silver Nitrate Solution ◽  
Thermal Degradation Kinetics ◽  
Face Centered Cubic ◽  
Transmission Electron ◽  
Face Centered ◽  
Kinetics Of ◽  
Better Than

Nanosilver/poly(acetoacetoxyethyl methacrylate–styrene) (nano-Ag/P(AAEM-St)) composites were synthesized via emulsifier-free emulsion with silver nitrate solution, AAEM, and St monomer copolymerization by ultrasonic. The morphology and structure of the composites were characterized by ultraviolet and visible spectroscopy, X-ray diffractometer, and transmission electron microscopy, respectively. The results show that Ag nanoparticles with face-centered cubic structure are homogeneously dispersed in the P(AAEM-St) matrix. The thermal stability and the thermal degradation kinetics of P(AAEM-St) were investigated using the thermogravimetric analysis and Kissinger and Flynn–Wall–Ozawa method, respectively. The results prove that the thermal stability of the pure P(AAEM-St) is better than that of the nano-Ag/P(AAEM-St) composites.

Nanoleakage in Hybrid Layer and Acid–Base Resistant Zone at the Adhesive/Dentin Interface

2015 ◽  
Vol 21 (5) ◽  
pp. 1271-1277 ◽  
Author(s):  
Toru Nikaido ◽  
Hamid Nurrohman ◽  
Tomohiro Takagaki ◽  
Alireza Sadr ◽  
Shizuko Ichinose ◽  
...  
Keyword(s):  
Nitrate Solution ◽  
Silver Nitrate Solution ◽  
Adhesive System ◽  
Control Group ◽  
Fluorescent Light ◽  
Adhesive Systems ◽  
Acid Base ◽  
Hybrid Layer ◽  
Transmission Electron ◽  
Self Etch

AbstractThe aim of interfacial nanoleakage evaluation is to gain a better understanding of degradation of the adhesive–dentin interface. The acid–base resistant zone (ABRZ) is recognized at the bonded interface under the hybrid layer (HL) in self-etch adhesive systems after an acid–base challenge. The purpose of this study was to evaluate nanoleakage in HL and ABRZ using three self-etch adhesives; Clearfil SE Bond (SEB), Clearfil SE One (SEO), and G-Bond Plus (GBP). One of the three adhesives was applied on the ground dentin surface and light cured. The specimens were longitudinally divided into two halves. One half remained as the control group. The others were immersed in ammoniacal silver nitrate solution, followed by photo developing solution under fluorescent light. Following this, the specimens were subjected to acid–base challenges with an artificial demineralization solution (pH4.5) and sodium hypochlorite, and prepared in accordance with common procedures for transmission electron microscopy (TEM) examination. The TEM images revealed silver depositions in HL and ABRZ due to nanoleakage in all the adhesives; however, the extent of nanoleakage was material dependent. Funnel-shaped erosion beneath the ABRZ was observed only in the all-in-one adhesive systems; SEO and GBP, but not in the two-step self-etch adhesive system; SEB.

Silver Nanoparticles - Trapping and Manipulation

2015 ◽  
Vol 832 ◽  
pp. 123-131
Author(s):  
E. Thanikaivalan ◽  
R. Jothilakshmi ◽  
P. Murugakoothan
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Nitrate Solution ◽  
Silver Nitrate Solution ◽  
Optical Scattering ◽  
Trapping Effect ◽  
Plasmon Resonance Band ◽  
Transmission Electron ◽  
Resonance Band ◽  
Gradient Forces

Silver nanoparticles with different radii were synthesized using silver nitrate solution added with sodium borohydride solution at different ratios. The synthesized silver nanoparticles of radii 25.3 nm, 31 nm, 33.6 nm and 37.1 nm were characterized by transmission electron microscopy (TEM) and UV-vis absorption spectroscopy. The synthesized silver nanoparticles exhibit spherical morphology for all radii. The silver nanoparticles exhibit the plasmon resonance band between 390 nm – 400 nm. The optical trapping effect of Gaussian beam acting on a silver nanoparticle in Rayleigh regime was studied. The optical scattering and optical gradient forces were calculated for silver nanoparticles of different radii.

Low temperature synthesis of ultrafine strontium titanate (SrTiO3) powders

1992 ◽  
Vol 7 (2) ◽  
pp. 429-434 ◽  
Author(s):  
H.S. Potdar ◽  
S.B. Deshpande ◽  
P.D. Godbole ◽  
V.G. Gunjikar ◽  
S.K. Date
Keyword(s):  
Low Temperature ◽  
Strontium Titanate ◽  
Room Temperature ◽  
Nitrate Solution ◽  
Strontium Nitrate ◽  
Distilled Water ◽  
Low Temperature Synthesis ◽  
Temperature Synthesis ◽  
Oxalate Solution ◽  
Titanyl Oxalate

Ultrafine (≍0.4 μm) strontium titanate powder was synthesized using strontium nitrate and potassium titanyl oxalate as precursors. An aqueous (0.1 M) potassium titanyl oxalate solution was added dropwise to a (0.1 M) strontium nitrate solution with continuous stirring at room temperature to precipitate strontium titanyl oxalate (STO). The precipitate, after careful washing with distilled water several times, was air-dried and calcined at 550 °C/6 h to obtain homogeneous, spherical, stoichiometric powder of SrTiO3 ≍0.4 μm in size. The calcined powder was characterized using different techniques such as XRD, DTA/TG/DTG, SEM, and IR.

Evolution of Textural, Structural and Morphological Properties of Ag/TiO2 Nanocomposites Tailored by Temperature

2009 ◽  
Vol 1174 ◽  
Author(s):  
Marcelo Viana ◽  
Nelcy Della Santina Mohallem
Keyword(s):  
Room Temperature ◽  
Nitrate Solution ◽  
Structural Evolution ◽  
Silver Nitrate Solution ◽  
Titanium Isopropoxide ◽  
Morphological Properties ◽  
Silver Particles ◽  
Oxidizing Power ◽  
Photoinduced Hydrophilicity

AbstractTiO2 is a promising material for use in environmental purification due to its strong oxidizing power, photoinduced hydrophilicity, non-toxicity and long-term photostability. Nanocomposites formed by silver dispersed in titania matrix have their application quality improved since silver particles can act in the electronic structure of the titania. In this work, titanium isopropoxide and silver nitrate solution was used as starting of Ag/TiO2 nanocomposites. After irradiation and gelification at room temperature, this material was dried and calcined at various temperatures up to 1100 °C. The nanocomposites were characterized to investigate the structural evolution of the nanoparticles and the dependence of crystallite size with the calcination temperature.

scholarly journals Evaluation of the Cytotoxic Activity of Biosynthesized Silver Nanoparticles Using Berberis vulgaris Leaf Extract

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Akbar Safipour Afshar ◽  
Fatemeh Saeid Nematpour
Keyword(s):  
Silver Nanoparticles ◽  
Cytotoxic Activity ◽  
Leaf Extract ◽  
Nitrate Solution ◽  
Silver Nitrate Solution ◽  
X Ray Diffraction ◽  
Berberis Vulgaris ◽  
Transmission Electron ◽  
Cancerous Cells ◽  
Mcf 7

Background: Recently, due to the numerous applications of silver nanoparticles (AgNPs) in industry, various routes to synthesize them have been developed. Objectives: The current study was aimed at synthesizing silver nanoparticles by the leaf extract of Berberis vulgaris and evaluating the cytotoxic effects on human breast cancer MCF-7 cell line. Methods: The leaf extract of Berberis vulgaris and silver nitrate solution were used to synthesize silver nanoparticles. Ultraviolet (UV)-visible, Fourier-transform infrared, and X-ray diffraction analysis spectroscopy and transmission electron microscopy methods were used to characterize and confirm the nanoparticles’ synthesis. The cytotoxic activity of synthesized nanoparticles (0, 5,10, 20, 40 µg/mL) was also studied by MTT assay. Results: The results showed that Ag nanoparticles were polydisperse and spherical in shape and had a size of about 19.9 nm. Silver nanoparticles reduced the growth of cancerous cells based on time and concentration. The IC50 for MCF-7 cells at 48 hours was 20.27 µg/mL. Conclusions: The findings showed that synthesized nanoparticles have an appropriate cytotoxic effect on cancer cells. This impact may be due to the production of free radicals through the release of Ag ions.

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