Adsorption of Silver Nanoparticles on Modified Surfaces

2015 ◽  
Vol 645-646 ◽  
pp. 75-79
Author(s):  
Can Gao ◽  
Tan Guo ◽  
Xiu Shen Ye ◽  
Hui Fang Zhang ◽  
Hai Ning Liu ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Self Assembly ◽  
Electrostatic Interactions ◽  
Average Diameter ◽  
Ag Nps ◽  
Electron Microscopic ◽  
Sem Images ◽  
Glass Slides ◽  
Transmission Electron ◽  
Adsorption Processes

Uniform films of silver nanoparticles (Ag NPs) were fabricated by self-assembly on 3-aminopropyltriethoxysilane (APTES) and [3-(2-aminoethyl) aminopropyl] trimethoxysilane (AEAPTES) modified glass slides. A stable Ag NPs suspension was synthesized via the reduction of silver nitrate using sodium citrate. Bulk characteristics of Ag NPs in aqueous solution were carried out by measuring their absorption spectrum, morphology and particle shape using the UV-vis absorption spectroscopy and transmission electron microscopy (TEM), respectively. The average diameter of Ag NPs is about 50 nm. The coverage of adsorbed particles on the modified glasses was measured by scanning electron microscopic imaging (SEM). The SEM images indicate that the Ag NPs films on the glasses are uniform. It is supposed that the adsorption processes are mainly controlled by electrostatic interactions. The adsorption amount of Ag NPs on APTES modified glass slides is much more than the amount on AEAPTES modified glass slides.

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 Size Control of Synthesized Silver Nanoparticles by Simultaneous Chemical Reduction and Laser Fragmentation in Origanum majorana Extract: Antibacterial Application

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2326
Author(s):  
Entesar Ali Ganash ◽  
Reem Mohammad Altuwirqi
Keyword(s):  
Silver Nanoparticles ◽  
Irradiation Time ◽  
Chemical Reduction ◽  
Size Control ◽  
Reduction Process ◽  
Laser Wavelength ◽  
X Ray Diffraction ◽  
Ag Nps ◽  
Transmission Electron ◽  
Origanum Majorana

In this work, silver nanoparticles (Ag NPs) were synthesized using a chemical reduction approach and a pulsed laser fragmentation in liquid (PLFL) technique, simultaneously. A laser wavelength of 532 nm was focused on the as produced Ag NPs, suspended in an Origanum majorana extract solution, with the aim of controlling their size. The effect of liquid medium concentration and irradiation time on the properties of the fabricated NPs was studied. While the X-ray diffraction (XRD) pattern confirmed the existence of Ag NPs, the UV–Vis spectrophotometry showed a significant absorption peak at about 420 nm, which is attributed to the characteristic surface plasmon resonance (SPR) peak of the obtained Ag NPs. By increasing the irradiation time and the Origanum majora extract concentration, the SPR peak shifted toward a shorter wavelength. This shift indicates a reduction in the NPs’ size. The effect of PLFL on size reduction was clearly revealed from the transmission electron microscopy images. The PLFL technique, depending on experimental parameters, reduced the size of the obtained Ag NPs to less than 10 nm. The mean zeta potential of the fabricated Ag NPs was found to be greater than −30 mV, signifying their stability. The Ag NPs were also found to effectively inhibit bacterial activity. The PLFL technique has proved to be a powerful method for controlling the size of NPs when it is simultaneously associated with a chemical reduction process.

Preparation of Triangular Silver Nanoparticles Using Polyvinyl Pyrrolidone with Different Concentration

2013 ◽  
Vol 873 ◽  
pp. 206-210
Author(s):  
Kai Li ◽  
Rao Fu ◽  
Qing Ran Gao ◽  
Ai Wei Tang ◽  
Ying Feng Wang
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Silver Nanoparticles ◽  
Driving Force ◽  
Ostwald Ripening ◽  
Polyvinyl Pyrrolidone ◽  
Protective Agent ◽  
Ag Nps ◽  
Transmission Electron ◽  
Uv Visible

This paper continues our previous work on preparation of triangular silver nanoparticles. The method proceeds with reaction of silver nitrate with hydrazine hydrate in the presence of polyvinyl pyrrolidone in aqueous solution. Effects of the concentration of PVP on the morphologies of Ag NPs were systematically investigated. The obtained Ag NPs were characterized by transmission electron microscopy and UV-visible spectrophotometer. The results showed that, triangular Ag NPs with edge lengths in the range of 50-200 nm were obtained using PVP as protective agent with lower concentration. As the concentration of PVP increased, spherical Ag NPs with their sizes about 6.2 nm were prepared and triangular Ag NPs were not obtained. The formation mechanism of triangular Ag NPs has been studied. Ostwald ripening is the driving force on the conversion of spherical Ag NPs to triangular Ag NPs in the presence of PVP.

scholarly journals Microwave-Assisted Green Synthesis of Silver Nanoparticles Using Juglans regia Leaf Extract and Evaluation of Their Physico-Chemical and Antibacterial Properties

Antibiotics ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 68 ◽  
Author(s):  
Mahsa Eshghi ◽  
Hamideh Vaghari ◽  
Yahya Najian ◽  
Mohammad Najian ◽  
Hoda Jafarizadeh-Malmiri ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Leaf Extract ◽  
Juglans Regia ◽  
Antibacterial Properties ◽  
Infrared Analysis ◽  
Ag Nps ◽  
Stabilizing Agents ◽  
Agno3 Solution ◽  
Transmission Electron ◽  
Vis Spectroscopy

Silver nanoparticles (Ag NPs) were synthesized using Juglans regia (J. regia) leaf extract, as both reducing and stabilizing agents through microwave irradiation method. The effects of a 1% (w/v) amount of leaf extract (0.1–0.9 mL) and an amount of 1 mM AgNO3 solution (15–25 mL) on the broad emission peak (λmax) and concentration of the synthesized Ag NPs solution were investigated using response surface methodology (RSM). Fourier transform infrared analysis indicated the main functional groups existing in the J. regia leaf extract. Dynamic light scattering, UV-Vis spectroscopy and transmission electron microscopy were used to characterize the synthesized Ag NPs. Fabricated Ag NPs with the mean particle size and polydispersity index and maximum concentration and zeta potential of 168 nm, 0.419, 135.16 ppm and −15.6 mV, respectively, were obtained using 0.1 mL of J. regia leaf extract and 15 mL of AgNO3. The antibacterial activity of the fabricated Ag NPs was assessed against both Gram negative (Escherichia coli) and positive (Staphylococcus aureus) bacteria and was found to possess high bactericidal effects.

scholarly journals Green Synthesis of Silver Nanoparticles in the Presence of Polysaccharide: Optimization and Characterization

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Margarita I. Skiba ◽  
Victoria I. Vorobyova ◽  
Alexander Pivovarov ◽  
Natalya P. Makarshenko
Keyword(s):  
Silver Nanoparticles ◽  
Sodium Alginate ◽  
Xrd Analysis ◽  
Face Centered Cubic ◽  
Colloidal Solutions ◽  
Ag Nps ◽  
Sem Images ◽  
Spherical Powder ◽  
Stabilizing Agent ◽  
Vis Spectroscopy

The process of obtaining aqueous solutions of silver nanoparticles with the use of a low-temperature nonequilibrium contact plasma and stabilizing agent—polysaccharide (sodium alginate)—has been examined. The synthesized Ag NPs were characterized by using UV-Vis spectroscopy, dynamic light scattering (DLS), scanning electron microscope (SEM), and XRD analysis. The effect of concentration of Ag+, sodium alginate, duration of processing by plasma discharge, and pH of liquid on the production of silver nanoparticles has been studied. The results demonstrated that synthesis provides the formation of silver nanoparticles for investigated concentrations of Ag+ (0.3-3.0 mmol/l) and 5.0 g/l Na-Alg (pH=7–10) within 1–5 minutes. From the SEM images, the silver nanoparticles are found to be almost spherical. Powder XRD results reveal that Ag nanoparticles have a face-centered cubic crystal structure. Zeta potential of plasma-chemically obtained colloidal solutions at various concentrations of Ag+ ions and stabilizing agent varies from −32.8 to −39.3 mV, indicating the moderate stability of synthesized nanoparticles.

scholarly journals Nanohydrogels Based on Self-Assembly of Cationic Pullulan and Anionic Dextran Derivatives for Efficient Delivery of Piroxicam

Pharmaceutics ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 622 ◽  
Author(s):  
Dorota Lachowicz ◽  
Przemyslaw Mielczarek ◽  
Roma Wirecka ◽  
Katarzyna Berent ◽  
Anna Karewicz ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Self Assembly ◽  
Electrostatic Interactions ◽  
Dextran Sulfate ◽  
Force Microscopy ◽  
Grafting Reaction ◽  
Atomic Force ◽  
Transmission Electron ◽  
Efficient Delivery ◽  
Model Drug

A cationic derivative of pullulan was obtained by grafting reaction and used together with dextran sulfate to form polysaccharide-based nanohydrogel cross-linked via electrostatic interactions between polyions. Due to the polycation-polyanion interactions nanohydrogel particles were formed instantly and spontaneously in water. The nanoparticles were colloidally stable and their size and surface charge could be controlled by the polycation/polyanion ratio. The morphology of the obtained particles was visualized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM). The resulting structures were spherical, with hydrodynamic diameters in the range of 100–150 nm. The binding constant (Ka) of a model drug, piroxicam, to the cationic pullulan (C-PUL) was determined by spectrophotometric measurements. The value of Ka was calculated according to the Benesi—Hildebrand equation to be (3.6 ± 0.2) × 103 M−1. After binding to cationic pullulan, piroxicam was effectively entrapped inside the nanohydrogel particles and released in a controlled way. The obtained system was efficiently taken up by cells and was shown to be biocompatible.

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.

REMOVAL OF THE SURFACTANT SURROUNDING Ag NANOCLUSTERS SYNTHESIZED BY NEW THERMAL DECOMPOSITION METHOD

2002 ◽  
Vol 01 (05n06) ◽  
pp. 477-481 ◽  
Author(s):  
LEE DON KEUN ◽  
YOUNG SOO KANG
Keyword(s):  
Thermal Decomposition ◽  
Silver Nanoclusters ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
Sem Images ◽  
X Ray ◽  
Transmission Electron ◽  
Thermo Gravimetric Analyzer ◽  
Ft Ir ◽  
Complex Transmission

Silver nanoclusters have been formed by thermal decomposition of Ag-oleate complex. Transmission electron microscopic (TEM) images of the particles showed two-dimensional assembly of particles with diameter of 10.5 nm. Energy-dispersive X-ray (EDX) spectrum and X-ray diffraction (XRD) peaks of the nanoclusters showed the highly crystalline nature of the silver structures. The decomposition of silver-oleate complex was analyzed by Thermo Gravimetric Analyzer (TGA) and the crystallization process was observed by XRD. The removal of the surfactant surrounding silver nanoclusters was measured by FT-IR and SEM images.

scholarly journals Structural Studies and Optical and Electrical Properties of Novel -Doped Nanorods

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Abdolali Alemi ◽  
Younes Hanifehpour ◽  
Sang Woo Joo ◽  
Bong-Ki Min ◽  
Tae Hwan Oh
Keyword(s):  
Electrical Conductance ◽  
Emission Spectra ◽  
Growth Direction ◽  
Electron Microscopic ◽  
Sem Images ◽  
Dopant Content ◽  
Cell Parameters ◽  
Transmission Electron ◽  
Xrd Patterns ◽  
Doped Nanomaterials

Gd3+-doped Sb2Se3nanorods were synthesized by coreduction method at 180°C and for 48 h. Powder XRD patterns indicate that the Se3crystals (–0.04) are isostructural with Sb2Se3. The cell parametersaandbincrease for Gd3+upon increasing the dopant content (x), whilecdecreases. SEM images show that doping of Gd3+ions in the lattice of Sb2Se3results in nanorods. High-resolution transmission electron microscopic (HRTEM) studies reveal that the Gd0.04Sb1.96Se3is oriented in the [10-1] growth direction. UV-Vis absorption reveals mainly electronic transitions of the Gd3+ions in doped nanomaterials. Emission spectra of doped materials show sharp emission band originating from f-f transition of the Gd3+ions. The electrical conductance of Gd-doped Sb2Se3is higher than undoped Sb2Se3and increases with temperature.

Synthesis and Characterization of Bone Cement (Hydroxyapatite Base) Calcinated at 900°C and Loading the Silver Nanoparticles on it

2012 ◽  
Vol 622-623 ◽  
pp. 893-896
Author(s):  
H.R. Ebrahimi ◽  
M. Eslami
Keyword(s):  
Silver Nanoparticles ◽  
Bone Cancer ◽  
Calcium Hydroxyapatite ◽  
Chemical Precipitation ◽  
X Ray Diffraction ◽  
Ag Nps ◽  
X Ray ◽  
Agno3 Solution ◽  
Transmission Electron

The bioceramics, calcium hydroxyapatite (HA), is a material which is biocompatible to the human body and is well suited to be used in hyperthermia applications for the treatment of bone cancer. We synthesis hydroxyapatite in modified synthetic body fluid (SBF) solutions at 37°C and pH of 7.4 using a novel chemical precipitation technique. Then after heat operation, on filtered precipitated result HA were produced. For loading the silver nanoparticles (Ag NPs) on the hydroxyapatite we use AgNO3 solution. And for reducing Ag+ ions apply sodium borohydrate solution. The formations of the silver nanoparticles on the HAP structure were confirmed by X-ray diffraction, transmission electron microscopy (TEM). TEM image show the nanostructure of silver particles, being formed on hydroxyapatite texture.

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