scholarly journals Reactivity and Chemical Sintering of Carey Lea Silver Nanoparticles

Nanomaterials ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1525
Author(s):  
Sergey Vorobyev ◽  
Elena Vishnyakova ◽  
Maxim Likhatski ◽  
Alexander Romanchenko ◽  
Ivan Nemtsev ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Silver Nanoparticles ◽  
Flexible Electronics ◽  
Photoelectron Spectroscopy ◽  
Colloidal Solutions ◽  
Ag Nps ◽  
Wide Range ◽  
Carboxylic Groups ◽  
The Media ◽  
Sulfide Ions

Carey Lea silver hydrosol is a rare example of very concentrated colloidal solutions produced with citrate as only protective ligands, and prospective for a wide range of applications, whose properties have been insufficiently studied up to now. Herein, the reactivity of the immobilized silver nanoparticles toward oxidation, sulfidation, and sintering upon their interaction with hydrogen peroxide, sulfide ions, and chlorocomplexes of Au(III), Pd(II), and Pt(IV) was investigated using SEM and X-ray photoelectron spectroscopy (XPS). The reactions decreased the number of carboxylic groups of the citrate-derived capping and promoted coalescence of 7 nm Ag NPs into about 40 nm ones, excluding the interaction with hydrogen peroxide. The increased nanoparticles form loose submicrometer aggregates in the case of sulfide treatment, raspberry-like micrometer porous particles in the media containing Pd(II) chloride, and densely sintered particles in the reaction with inert H2PtCl6 complexes, probably via the formation of surface Ag-Pt alloys. The exposure of Ag NPs to HAuCl4 solution produced compact Ag films along with nanocrystals of Au metal and minor Ag and AgCl. The results are promising for chemical ambient temperature sintering and rendering silver-based nanomaterials, for example, for flexible electronics, catalysis, and other applications.

scholarly journals Alginate-Mediated Synthesis of Hetero-Shaped Silver Nanoparticles and Their Hydrogen Peroxide Sensing Ability

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 435 ◽  
Author(s):  
Sneha Bhagyaraj ◽  
Igor Krupa
Keyword(s):  
Hydrogen Peroxide ◽  
Particle Size ◽  
Silver Nanoparticles ◽  
Linear Response ◽  
X Ray Diffraction ◽  
Ag Nps ◽  
X Ray ◽  
Transmission Electron ◽  
Wide Range ◽  
Pollution Detection

A new method for the simple synthesis of stable heterostructured biopolymer (sodium alginate)-capped silver nanoparticles (Ag-NPs) based on green chemistry is reported. The as-prepared nanoparticles were characterized using the ultraviolet-visible (UV-Vis) absorption spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and dynamic light scattering (DLS) techniques. The results showed that the as-prepared Ag-NPs have a heterostructured morphology with particle size in the range 30 ± 18–60 ± 25 nm, showing a zeta potential of −62 mV. The silver nanoparticle formation was confirmed from UV-Vis spectra showing 424 nm as maximum absorption. The particle size and crystallinity of the as-synthesized nanoparticles were analyzed using TEM and XRD measurements, respectively. FTIR spectra confirmed the presence of alginate as capping agent to stabilize the nanoparticles. The Ag-NPs also showed excellent sensing capability, with a linear response to hydrogen peroxide spanning a wide range of concentrations from 10−1 to 10−7 M, which indicates their high potential for water treatment applications, such as pollution detection and nanofiltration composites.

scholarly journals Alginate-Mediated Synthesis of Hetero-Shaped Silver Nanoparticles and their Hydrogen Peroxide Sensing ability

2020 ◽  
Author(s):  
Sneha Bhagyaraj ◽  
Igor Krupa
Keyword(s):  
Hydrogen Peroxide ◽  
Particle Size ◽  
Silver Nanoparticles ◽  
Environmentally Benign ◽  
X Ray Diffraction ◽  
Ag Nps ◽  
X Ray ◽  
Transmission Electron ◽  
Wide Range ◽  
Pollution Detection

Silver nanoparticles have been the focus of extensive research for many decades due to their unique physical, chemical and electrical properties. Introducing new environmentally benign methods for the synthesis of silver nanoparticles is of great interest in the research community. In this work we propose a new method for the simple synthesis of stable heterostructured biopolymer (sodium alginate)-capped silver nanoparticles (Ag-NPs) based on green chemistry.The as-prepared nanoparticles were characterized using the ultraviolet–visible (UV–Vis) absorption spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and Dynamic light scattering (DLS) techniques. The results showed that the as-prepared Ag-NPs have a heterostructured morphology with particle size in the range 30 ± 18 – 60 ± 25 nm, showing a zeta potential of -62 mV. The silver nanoparticle formation was confirmed from UV-Vis spectra showing 424 nm as maximum absorption. The particle size and crystallinity of the as- synthesized nanoparticles were analyzed using TEM and XRD measurements respectively. FTIR spectra confirmed the presence of alginate as capping agent to stabilize the nanoparticles. The Ag-NPs also showed excellent sensing capability, with a linear response to hydrogen peroxide spanning a wide range of concentrations from 10-1 – 10-7 M, which indicates their high potential for water treatment applications, such as pollution detection and nanofiltration composites.

scholarly journals Preparation of Silver Nanoparticles and Their Industrial and Biomedical Applications: A Comprehensive Review

2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
Adnan Haider ◽  
Inn-Kyu Kang
Keyword(s):  
Silver Nanoparticles ◽  
Biomedical Applications ◽  
Consumer Products ◽  
Ag Nps ◽  
New Techniques ◽  
Governing Factor ◽  
Wide Range ◽  
Microbial Proliferation ◽  
Synthetic Routes ◽  
Biomedical Fields

Silver nanoparticles (Ag-NPs) have diverted the attention of the scientific community and industrialist itself due to their wide range of applications in industry for the preparation of consumer products and highly accepted application in biomedical fields (especially their efficacy against microbes, anti-inflammatory effects, and wound healing ability). The governing factor for their potent efficacy against microbes is considered to be the various mechanisms enabling it to prevent microbial proliferation and their infections. Furthermore a number of new techniques have been developed to synthesize Ag-NPs with controlled size and geometry. In this review, various synthetic routes adapted for the preparation of the Ag-NPs, the mechanisms involved in its antimicrobial activity, its importance/application in commercial as well as biomedical fields, and possible application in future have been discussed in detail.

The electrocatalytic response of metallophthalocyanines when clicked to electrodes and to nanomaterials

2021 ◽  
Author(s):  
◽  
Lekhetho Simon Mpeta
Keyword(s):  
Hydrogen Peroxide ◽  
Silver Nanoparticles ◽  
Zinc Oxide ◽  
Photoelectron Spectroscopy ◽  
Electrocatalytic Activity ◽  
Electrochemical Impedance ◽  
Modified Electrodes ◽  
Transmission Electron ◽  
Reduced Graphene ◽  
Electrochemical Microscopy

Conjugates of nanomaterials and metallophthalocyanines (MPcs) have been prepared and their electrocatalytic activity studied. The prepared nanomaterials are zinc oxide and silver nanoparticles, reduced graphene oxide nanosheets and semiconductor quantum dots. The MPcs used in this work are cobalt (II) (1a), manganese(III) (1b) and iron (II) (1c) 2,9(10),16(17),23(24)- tetrakis 4-((4-ethynylbenzyl) oxy) phthalocyaninato, 2,9(10),16(17),23(24)- tetrakis(5-pentyn-oxy) cobalt (II) phthalocyaninato (2), 9(10),16(17),23(24)- tris-[4-tert-butylphenoxy)-2- (4-ethylbezyl-oxy) cobalt (II) phthalocyaninato (3), 9(10),16(17),23(24)- tris-[4-tertbutylphenoxy)-2-(pent-4yn-yloxy)] cobalt (II) phthalocyaninato (4), cobalt (II) (5a) and manganese (III) (5b) 2,9(10),16(17),23(24)- tetrakis [4-(4-(5-chloro-1H-benzo [d]imidazol-2-yl)phenoxy] phthalocyaninato and 9(10),16(17),23(24)- tris tert butyl phenoxy- 2- [4-(4-(5-chloro-1H-benzo[d]imidazole-2-yl)phenoxy] cobalt (II) phthalocyaninato (6). Some of these MPcs (1a, 3 and 4) were directly clicked on azide grafted electrode, while some (1b, 1c, 2, 5a and 5b) were clicked to azide functionalised nanomaterials and then drop-dried on the electrodes. One phthalocyanine (5b) was drop-dried on the electrode then silver nanoparticles were electrodeposited on it taking advantage of metal-N bond. Scanning electrochemical microscopy, voltammetry, chronoamperometry, electrochemical impedance spectroscopy are among electrochemical methods used to characterise modified electrodes. Transmission electron microscopy, X-ray photoelectron spectroscopy, Xray diffractometry, Raman spectroscopy and infrared spectroscopy were employed to study surface functionalities, morphology and topography of the nanomaterials and complexes. Electrocatalytic activity of the developed materials were studied towards oxidation of 2-mercaptoethanol, hydrazine and hydrogen peroxide while the reduction study was based on oxygen and hydrogen peroxide. In general, the conjugates displayed superior catalytic activity when compared to individual materials. Complex 2 alone and when conjugated to zinc oxide nanoparticles were studied for their nonlinear optical behaviour. And the same materials were explored for their hydrazine detection capability. The aim of this study was to develop sensitive, selective and affordable sensors for selected organic waste pollutants. Conjugates were found to achieve the aim of the study compared to when individual materials were employed.

The plasma-chemical formation of polysorbate 80-coated silver nanoparticles and composite materials for water treatment

2019 ◽  
Vol 48 (5) ◽  
pp. 431-438 ◽  
Author(s):  
Margarita Ivanovna Skiba ◽  
Viktoria Vorobyova
Keyword(s):  
Silver Nanoparticles ◽  
Water Treatment ◽  
Low Temperature ◽  
Polysorbate 80 ◽  
Low Temperature Plasma ◽  
Colloidal Solutions ◽  
Ag Nps ◽  
Temperature Plasma ◽  
Content Type ◽  
Water Treatment Process

Purpose This paper aims to propose a simple, eco-friendly method for obtaining colloidal solutions of silver nanoparticles (Ag NPs) by using of contact non-equilibrium low-temperature plasma in presents polysorbate-80 and to assess their antibacterial activity in composite materials (beads) for water treatment process. Design/methodology/approach Silver nanoparticles were prepared in aqueous AgNO3 solution by using of contact non-equilibrium low-temperature plasma in the present of nonionic surfactant polysorbate-80 (Tween 80) as capping agent. Ultraviolet–visible (UV) spectroscopy, X-ray diffraction and zeta potential analysis were used to study the formation and properties of silver nanoparticles. Findings The formation of silver colloidal solutions in the presence of capping agent under plasma discharge is characterized by the presence of peak λmax = 380 – 402 nm in the spectra. The addition of sodium alginate into the reaction mixture allows synthesizing stable colloidal silver solutions. The average size of formed silver particles is up to 50 nm. Ag NPs exhibited an excellent bactericidal activity against both gram-positive and gram- negative bacteria. Composite beads prepared using nonionic surfactant were found to be effective in disinfecting the Staphylococcus aureus to different extents. Research limitations/implications Further studies are necessary for confirmation of the practical application, especially of the toxicity of Ag NPs, as well as the sorption properties of the alginate beads with Ag NPs. Practical implications The method provides a simple and practical solution to improving the synthesis of colloidal solutions of Ag NPs for water treatment process. Originality/value Contact nonequilibrium low-temperature plasma can be used as an effective technique for synthesis of nanomaterials.

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 Ultrasonic synthesized Konjac gum/PEG-silver nanoparticles for colorimetric detection of hydrogen peroxide

2021 ◽  
Author(s):  
SELCAN KARAKUŞ ◽  
Nevin Taşaltın ◽  
Cihat Taşaltın ◽  
Nuray Bekoz Üllen
Keyword(s):  
Hydrogen Peroxide ◽  
Silver Nanoparticles ◽  
Biomedical Applications ◽  
Limit Of Detection ◽  
Low Cost ◽  
Colorimetric Detection ◽  
Rheological Parameters ◽  
Ag Nps ◽  
Synthesis Strategy ◽  
Konjac Gum

Abstract Green and low-cost synthesis strategy for ultrasonic preparation of polymer blend matrix based silver nanoparticles (Ag NPs) and the development of rapid and high sensitive detection route have a great attention in biomedical applications. Therefore, in this study, we investigated the hydrogen peroxide detection performance of Konjac gum (KG)/PEG-Ag NPs. The KG/PEG-Ag NPs was synthesized via an ultrasonic process and characterized by different techniques such as ultraviolet–visible spectroscopy (UV–Vis), Fourier-Transform Infrared spectroscopy (FT-IR), Scanning Electron Microscope (SEM) and Energy Dispersive X-ray spectroscopy (EDX). Furthermore, we determined the experimental optimization on the effect of the rheological parameters of nanostructure with the highest correlation constant (R 2 : 0.989-0.996), and the intrinsic viscosity (14.71-26.77 dl/g). To provide the miscible polymer blends and homogeneous dispersion of the nanostructure, we compared the rheological parameters with the experimental results. The response time was less than 5 s and the lower limit of detection was 0.071 μM. This novel highly sensitive, rapid, and naked-eye colorimetric biosensor based Ag NPs which are prepared ultrasonic manufacturing approach, opens up a green approach of development facile and rapid detection of hydrogen peroxide in practical biomedical applications.

scholarly journals Sonoelectrochemical synthesis of silver nanoparticles in polyvinylpyrrolidone solutions

2021 ◽  
Vol 4 (1) ◽  
pp. 82-87
Author(s):  
M. V. Shepida ◽  
◽  
M. A. Sozanskyi ◽  
Yu. V. Sukhatskiy ◽  
A. S. Mazur ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Formation Rate ◽  
Ultrasonic Field ◽  
Colloidal Solutions ◽  
Complex Ions ◽  
Diffusion Kinetic ◽  
Wide Range ◽  
Sonoelectrochemical Synthesis ◽  
The Stability ◽  
Sonochemical Reduction

The results of investigations of the influence of main parameters (surfactant concentration and temperature) on the synthesis of silver nanoparticles (AgNPs) by the sonoelectrochemical method in polyvinylpyrrolidone (PVP) solutions by cyclic voltammetry (CVA) are presented. It is shown that the ultrasonic field (22 kHz) leads to an increase in the anodic and cathodic currents by ~30 %. A scheme of the AgNPs formation has been proposed, which includes the following main processes: 1) dissolution of sacrificial silver anodes at E = 0.2...1.0 V with the formation of [AgPVP]+ complex ions; 2) cathodic and sonochemical reduction of the latter to Ag(0); 3) formation of AgNPs. It has been established that with an increase in PVP concentration from 1 to 4 g·L-1, the anodic and cathodic currents decrease by 40–60 %. The formation rate of AgNPs also decreases. The growth of anodic and cathodic currents and the formation rate of nanoparticles in the range of 20…60 °C corresponds to the diffusion-kinetic action of the temperature factor. The CVA curves practically do not change in time, which indicates the stability of anodic and cathodic processes at prolonged sonoelectrochemical synthesis. The character of the UV-Vis spectra of AgNPs colloidal solutions in PVP with the 405…410 nm absorption maximum is the same in a wide range of nanoparticle concentrations.

scholarly journals Carbene modification and reversible crosslinking of silver nanoparticles for controlled antibacterial activity

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Liling Jing ◽  
Mark G. Moloney ◽  
Hao Xu ◽  
Lian Liu ◽  
Wenqiang Sun ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Photoelectron Spectroscopy ◽  
Inhibition Zone ◽  
Insertion Reaction ◽  
Ag Nps ◽  
Zone Method ◽  
Transmission Electron

Abstract Silver nanoparticles (Ag NPs) system capable of exhibiting different particle size at different temperature was developed, which depended on the extent of Diels–Alder (DA) reaction of bismaleimide with furan. Thus, Ag NPs were functionalized on the surface by a furyl-substituted carbene through an insertion reaction. Subsequent reversible DA crosslinking achieved a controlled aggregation with different particle size, which gives a series of different antibacterial activity. These Ag NPs were characterized by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS), and Nanoparticle Size Analyzer. The aggregation of the Ag NPs could be reliably adjusted by varying the temperature of DA/reverse-DA reaction. The antibacterial activity was assessed using the inhibition zone method against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), which decreased first and then increased in agreement with the size evolution of Ag NPs. This approach opens a new horizon for the carbene chemistry to modify silver nanoparticles with variable size and give controlled antibacterial activity.

scholarly journals Flexible Perovskite Solar Cells via Surface-Confined Silver Nanoparticles on Transparent Polyimide Substrates

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 427 ◽  
Author(s):  
Xiangfu Liu ◽  
Lin Hu ◽  
Rongwen Wang ◽  
Junli Li ◽  
Honggang Gu ◽  
...  
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Solar Cells ◽  
Flexible Electronics ◽  
Short Circuit ◽  
Flexible Substrate ◽  
Perovskite Solar Cells ◽  
Interparticle Distance ◽  
Localized Surface Plasmon ◽  
Ag Nps

We report about a flexible substrate incorporating surface-confined silver nanoparticles on transparent polyimide (PI). The incorporated silver nanoparticles (Ag NPs), which possessed excellent adhesive strength with the PI substrate, induced localized surface plasmon resonance and light scattering effects by changing the particle size and interparticle distance to promote light harvesting in the perovskite solar cells. Moreover, the reduced sheet resistance was beneficial for the charge extraction and transportation in the devices when high-conductivity poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS, PH1000) was deposited on the Ag NP-confined PI serving as a flexible bottom electrode. A power conversion efficiency of 10.41% was obtained for the flexible perovskite solar cells based on a Ag NP-confined PI substrate (the particle size of the Ag NPs was 25 nm mixed with 40 nm), which was obviously enhanced in all parameters. Especially, a 61% improvement existed in the short-circuit current density compared to that based on the bare PI substrates. It indicates that the substrate would be a promising candidate for the development of flexible electronics.

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