Preparation of silver nanoparticles using atmospheric discharge plasma for catalytic reduction of p-nitrophenol: the influence of pressure in the reactor

2020 ◽  
Vol 49 (6) ◽  
pp. 449-456 ◽  
Author(s):  
Margarita Skiba ◽  
Viktoria Vorobyova ◽  
Alexander Pivovarov ◽  
Inna Trus
Keyword(s):  
Silver Nanoparticles ◽  
Discharge Plasma ◽  
Uv Spectroscopy ◽  
Spherical Particles ◽  
Colloidal Solutions ◽  
Ag Nps ◽  
Sem Images ◽  
Temperature Plasma ◽  
Content Type ◽  
Atmospheric Discharge

Purpose This paper aims to synthesize silver nanoparticles using atmospheric discharge plasma in contact with liquid at different pressure in reactor and to assess their catalytical properties for reducing 4-nanoparticles (NP). Design/methodology/approach The Ag colloidal NPs was rapidly synthesized as a result of non-equilibrium low-temperature plasma formation between an electrode and the surface of AgNO3 solution for 5 min at different pressure in reactor. Synthesized Ag NPs were characterized with common analytical techniques. Ultraviolet–visible (UV) spectroscopy, dynamic light scattering, scanning microcopy analysis were used to study the formation and characteristics of silver nanoparticles. Findings The formation of silver colloidal solutions under plasma discharge at different pressure in reactor is characterized by the presence of surface resonance peak in the spectra. Scanning electron microscope (SEM) images confirmed the formation of spherical particles having a size distribution in the range of 15-26 nm. The AgNPs solution showed excellent rapid catalytic activity for the complete degradation of toxic 4-nitrophenol (4-NPh) into non-toxic 4-aminophenol (4-APh) within 18 min. Research limitations/implications Further studies are necessary for confirmation of the practical application, especially of deposition Ag NPs on TiO2. Practical implications The method provides a simple and practical solution to improving the synthesis of colloidal solutions of Ag NPs for degradation of organic pollutants (4-NPh) in water and wasters water. Originality/value Atmospheric discharge plasma in contact with liquid at different pressure can be used as an effective technique for synthesis of nanomaterials with catalytic properties.

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 Antibacterial activity of royal jelly-mediated green synthesized silver nanoparticles

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Susanna Gevorgyan ◽  
Robin Schubert ◽  
Mkrtich Yeranosyan ◽  
Lilit Gabrielyan ◽  
Armen Trchounian ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Green Synthesis ◽  
Royal Jelly ◽  
Fluorescence Emission ◽  
Spherical Particles ◽  
Ag Nps ◽  
Gram Negative ◽  
Green Synthesized Silver Nanoparticles ◽  
Higher Sensitivity

AbstractThe application of green synthesis in nanotechnology is growing day by day. It’s a safe and eco-friendly alternative to conventional methods. The current research aimed to study raw royal jelly’s potential in the green synthesis of silver nanoparticles and their antibacterial activity. Royal jelly served as a reducing and oxidizing agent in the green synthesis technology of colloidal silver nanoparticles. The UV–Vis maximum absorption at ~ 430 nm and fluorescence emission peaks at ~ 487 nm confirmed the presence of Ag NPs. Morphology and structural properties of Ag NPs and the effect of ultrasound studies revealed: (i) the formation of polydispersed and spherical particles with different sizes; (ii) size reduction and homogeneity increase by ultrasound treatment. Antibacterial activity of different concentrations of green synthesized Ag NPs has been assessed on Gram-negative S. typhimurium and Gram-positive S. aureus, revealing higher sensitivity on Gram-negative bacteria.

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.

SYNTHESIS AND CHARACTERIZATION OF SILVER NANOPARTICLES EMBEDDED IN EMULSIFIED ISOBUTYL ACRYLATE

2013 ◽  
Vol 12 (05) ◽  
pp. 1350041
Author(s):  
C. DENNIS ◽  
S. VIDHYA ◽  
K. SHADAK ALEE ◽  
D. NARAYANA RAO
Keyword(s):  
Silver Nanoparticles ◽  
Synthesis And Characterization ◽  
Spherical Nanoparticles ◽  
Colloidal Solutions ◽  
Sem Images ◽  
Atomic Force ◽  
Infrared Spectrophotometer ◽  
Laser Ablation Technique ◽  
Scanning Electron

Silver nanoparticles were generated using laser ablation technique in emulsified isobutyl acrylate solution in which the nanoparticles are stabilized and embedded over the acrylic polymerized solution. Further, the colloidal solutions were characterized with atomic force microscope (AFM), scanning electron microscope (SEM) and Fourier transform infrared spectrophotometer (FTIR). AFM image results of the nanoparticles displays the silver nanoparticles embedded over the emulsified acrylic layer and dispersion of spherical nanoparticles across the polymer were eruptions of silver nanoparticles can be seen clearly. In addition, FTIR spectrum and SEM images validate the nanoparticle reaction over the polymerized acrylate solution and size of the metal nanoparticles respectively.

Catechol End-Functionalized Polysarcosine for In-situ Synthesis and Stabilization of Silver Nanoparticles

MRS Advances ◽  
2020 ◽  
Vol 5 (21-22) ◽  
pp. 1113-1120
Author(s):  
Hailemariam Gebru ◽  
Zhenjiang Li
Keyword(s):  
Silver Nanoparticles ◽  
Metallic Nanoparticles ◽  
In Situ Synthesis ◽  
High Concentration ◽  
Ag Nps ◽  
Sem Images ◽  
Stabilizing Agents ◽  
H Nmr ◽  
Dopamine Hydrochloride

ABSTRACTFunctional polymers were previously employed to minimize the susceptibility of metallic nanoparticles (MNPs) for aggregation. Herein, we intended to conjugate catechol moiety into the polymer chain end considering its anchoring ability to virtually most surfaces. Accordingly, catechol end-functionalized polysarcosine (cat-PSar) was successfully prepared from the ring-opening polymerization (ROP) of sarcosine N-carboxyanhydrides (Sar-NCA) using dopamine hydrochloride initiator. ROP of Sar-NCA was carried out at different monomer to initiator feed ratios. The molecular structure of cat-PSar was confirmed by 1H NMR and MALDITOF. Afterward, the obtained catechol functionalized polymer was used for in-situ synthesis and stabilization of silver nanoparticles (Ag-NPs) in aqueous solution. The observed characteristic absorption peak at λmax of 415 nm indicates the formation of Ag-NPs. Scanning electron microscope (SEM) images also elucidate the formation of Ag-NPs with the relatively small sizes of the nanocomposite at a high concentration of silver nitrate. Hence, biomimetic polymers could play a dual role as reducing and stabilizing agents in the preparation of monodispersed MNPs.

scholarly journals Synthesis of Silver Nanoparticles Using Dichloromethane Extract of Chrysanthemum cinerariaefolium and Its Bioactivity

2021 ◽  
Vol 6 (1) ◽  
pp. 1-17
Author(s):  
Caroline Jepchirchir Kosgei ◽  
Meshack Amos Obonyo ◽  
Josphat Clement Matasyoh ◽  
James J. Owuor ◽  
Moses A. Ollengo ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Metallic Nanoparticles ◽  
Colour Change ◽  
Vero Cells ◽  
Ag Nps ◽  
Absorption Bands ◽  
Sem Images ◽  
Average Size ◽  
Chrysanthemum Cinerariaefolium

Common methods of synthesizing metallic nanoparticles are chemical and physical. However, they are expensive and use toxic chemicals. Green synthesis is less costly and safer hence a potential alternative. Silver nanoparticles (Ag NPs) were synthesized using dichloromethane extract of Chrysanthemum cinerariaefolium and colour change from pale green to dark brown was observed. Scanning Electron Microscopy (SEM) images were faceted and others formed clusters. Transmission Electron Microscopy (TEM) images were spherical with an average size of 22.8± 17.5 nm. EDX analysis showed the nanoparticles had percentage abundance of 67.26%. Fourier-transform Infrared Spectroscopy (FTIR) analysis showed absorption bands at 3489.59 cm-1, 3217.80 cm-1, 2384.74 cm-1 , 1633.05 cm-1, 1405.08 cm-1, 1109.32 cm-1 and 505.93 cm-1. The UV-Vis analysis showed Surface Plasmon Resonance (SPR) peak at 434 nm. The nanoparticles were more active on P. aeruginosa with an MIC of 15 µg/ml while the cytotoxicity assay showed Ag NPs had an MIC of 33.33 µg/ml hence were noncytotoxic against Vero cells.

GREEN SYNTHESIS OF SILVER NANOPARTICLES, METHOD DEVELOPMENT AND VALIDATION BY UV SPECTROSCOPY IN BULK PHARMACEUTICALS

INDIAN DRUGS ◽  
2021 ◽  
Vol 57 (10) ◽  
pp. 23-29
Author(s):  
Vipul Patel ◽  
Unnati Patel
Keyword(s):  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Method Development ◽  
Uv Spectroscopy ◽  
Spectroscopic Method ◽  
Colour Change ◽  
Toxic Waste ◽  
Ag Nps ◽  
Datura Metel ◽  
Validation Parameters

The silver nanoparticle is an antibacterial, nontoxic agent. Its conventional synthesis usually generates toxic waste while reaction proceeds hence, green synthesis approach is used have for synthesis of silver nanoparticles (Ag-NPs) by using Datura metel leaf extract as reducing agent. The colour change from colourless to brown was the visual identification for formation of Ag-NPs and showed absorption at 447 nm. The Ag-NPs were of size 180 nm analysed by SEM and characterised by FTIR, where carboxylic peak was obtained at 1569 cm-1, besides confirming presence of alcoholic group and polyphenols. Further, validated method was developed and linearity was found to be 0.995 and % RSD of validation parameters was found to be within the limit <2%. A simple, lab scale, rapid, accurate, precise and sensitive spectroscopic method has been developed and validated as per ICH guideline for synthesized Ag-NPs in bulk pharmaceuticals by UV vis spectrophotoscopy and it is applicable for routine analysis.

scholarly journals Rapid Green Synthesis and Characterization of Silver Nanoparticles Arbitrated by Curcumin in an Alkaline Medium

Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 719 ◽  
Author(s):  
Muhammad Khan ◽  
Kamyar Shameli ◽  
Awis Sazili ◽  
Jinap Selamat ◽  
Suriya Kumari
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Alkaline Medium ◽  
Research Area ◽  
Crystallographic Structure ◽  
Face Centered Cubic ◽  
Colloidal Solutions ◽  
Ag Nps ◽  
Vis Spectroscopy

Green synthesis of silver nanoparticles is desirable practice. It is not only the required technique for industrial and biomedical purposes but also a promising research area. The aim of this study was to synthesize green curcumin silver nanoparticles (C-Ag NPs). The synthesis of C-Ag NPs was achieved by reduction of the silver nitrate (AgNO3) in an alkaline medium. The characterizations of the prepared samples were conducted by ultraviolet visible (UV-vis) spectroscopy, powder X-ray diffraction (PXRD), field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED) and zeta potential (ZP) analyses. The formation of C-Ag NPs was evaluated by the dark color of the colloidal solutions and UV-vis spectra, with 445 nm as the maximum. The size of the crystalline nanoparticles, recorded as 12.6 ± 3.8nm, was confirmed by HRTEM, while the face-centered cubic (fcc) crystallographic structure was confirmed by PXRD and SAED. It is assumed that green synthesized curcumin silver nanoparticles (C-Ag NPs) can be efficiently utilized as a strong antimicrobial substance for food and meat preservation due to their homogeneous nature and small size.

Phyto-mediated silver nanoparticles via Mellisa officinalis aqueous and methanolic extracts: synthesis, characterization and biological properties

2020 ◽  
Author(s):  
Fatemeh Dehghan Nayeri ◽  
Sudabeh Mafakheri ◽  
Maryam Mirhosseini
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Methanolic Extract ◽  
Biological Properties ◽  
Spherical Particles ◽  
Sem Images ◽  
Lemon Balm ◽  
Methanolic Extracts ◽  
Resonance Band ◽  
Vis Spectroscopy

Abstract The aim of the study was to examine the influence of extraction method on the size, shape and morphology of synthesized silver nanoparticles (AgNPs). Silver nanoparticles were prepared by the aqueous and methanolic extracts of lemon balm. The properties of obtained nanoparticles were characterized by UV-Vis, SEM, XRD and FTIR techniques. The UV-Vis spectroscopy confirmed the formation of AgNPs by observing a distinct surface Plasmon resonance band around 450 nm. SEM images showed different shape, size and morphology of AgNPs using two different extracts types. AgNPs derived from the aqueous extract were rod-shaped with a diameter of 19 to 40 nm whereas spherical particles were synthesized by the methanolic extract found smaller with size distribution ranging from 13 to 35 nm. The XRD pattern indicated that AgNPs formed by the reduction of Ag + ions using methanolic extract of M. officinalis were crystal-like in nature. The functional groups of M. officinalis methanolic extract involved in synthesis and stabilization of AgNPs were investigated by FTIR. In addition, AgNPs-containing methanolic extract showed higher antioxidant activity. These particles exhibited remarkable antimicrobial activity against gram positive and negative bacteria and a fungus. The nanoparticles produced by the methanolic extract of the lemon balm showed antioxidant and antimicrobial activity. The production of silver nanoparticles using plant extract is rapid, low cost and eco-friendly. Therefore, green chemistry is a good alternative to industrial production of nanoparticles. Silver nanoparticles can be used as an antiseptic to sterilize the surrounding area and the hospital wastes.

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