Preparation of silver nanoparticles in a high voltage AC arc in water

AbstractThe article presents for the first time the synthesis of silver nanoparticles in an electric arc of high-voltage alternating current with a frequency of 50 Hz. In particular, the method and apparatus necessary for the preparation of nanoparticles in water solution is discussed. Current–voltage characteristics depending on the mutual distance between the electrodes are presented which show a very high stability of the generated discharge phenomena. The obtained nanoparticles were examined using various analytical techniques such as UV–Vis spectroscopy, dynamic light scattering (DLS), zeta potential, energy dispersive X-Ray analysis (EDS), X-ray diffraction (XRD), and X-ray fluorescence (EDXRF). The morphology, surface and size of the obtained nanoparticles was carried out using transmission electron microscopy (TEM) and scanning TEM (STEM) equipped with the annual dark-field imaging scanning atomic-scale chemical mapping (STEM). The designed simple power supply unit consisting of an autotransformer and a microwave oven transformer (MOT) makes the preparation of silver nanoparticles both simple and economical.

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Synthesis and Characterization of Silver Nanoparticles Using Alginate from the Brown Seaweed Laminaria ochroleuca: Structural Features and Antibacterial Activity

Biointerface Research in Applied Chemistry ◽

10.33263/briac125.60466057 ◽

2021 ◽

Vol 12 (5) ◽

pp. 6046-6057

Keyword(s):

Silver Nanoparticles ◽

Antibacterial Activity ◽

Sodium Alginate ◽

Brown Seaweed ◽

Analytical Techniques ◽

Spherical Shape ◽

Structural Features ◽

X Ray ◽

Vis Spectroscopy ◽

Laminaria Ochroleuca

In this study, inexpensive and eco-friendly production of the silver nanoparticles (AgNPs) was explored using Laminaria ochroleuca sodium alginate as stabilizing and reducing agent. The synthesized nanoparticles were characterized by various analytical techniques such as UV–Vis spectroscopy, Energy dispersive X-ray spectrometer (EDX), X-ray diffraction (XRD), transmission electron microscopy (TEM), TEM selected area electron diffraction (SAED), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric analysis (TGA). The synthesis of AgNPs was elucidated by characteristic absorption peaks in the UV–Vis test. The FTIR analysis revealed the involvement of many functional groups in the bioreduction and the stabilization of AgNPs, while TEM images illustrated the spherical shape with maximum particles found in the size range of 10-20 nm. Prominent peaks and silver diffraction rings shown by the XRD spectrum and SAED pattern, respectively, confirmed the crystalline nature (fcc) of the synthesized AgNPs, which were found to be thermally stable based on TGA analysis. The AgNPs exhibited strong antibacterial activity against Gram+ and Gram– bacteria. The synthesized silver nanoparticles using Laminaria ochroleuca sodium alginate revealed interesting properties that could be potentially used for pharmaceutical applications.

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Exposure Media and Nanoparticle Size Influence on the Fate, Bioaccumulation, and Toxicity of Silver Nanoparticles to Higher Plant Salvinia minima

Molecules ◽

10.3390/molecules26082305 ◽

2021 ◽

Vol 26 (8) ◽

pp. 2305

Author(s):

Melusi Thwala ◽

Stephen Klaine ◽

Ndeke Musee

Keyword(s):

Silver Nanoparticles ◽

Analytical Techniques ◽

Hard Water ◽

Higher Plant ◽

X Ray ◽

Chlorophyll Pigments ◽

Size Dependent ◽

Predicted Environmental Concentrations ◽

Low Exposure ◽

Toxicity Pattern

Silver nanoparticles (AgNPs) are favoured antibacterial agents in nano-enabled products and can be released into water resources where they potentially elicit adverse effects. Herein, interactions of 10 and 40 nm AgNPs (10-AgNPs and 40-AgNPs) with aquatic higher plant Salvinia minima at 600 µg/L in moderately hard water (MHW), MHW of raised calcium (Ca2+), and MHW containing natural organic matter (NOM) were examined. The exposure media variants altered the AgNPs’ surface properties, causing size-dependent agglomeration. The bio-accessibility in the ascending order was: NOM < MHW < Ca2+, was higher in plants exposed to 10-AgNPs, and across all exposures, accumulation was higher in roots compared to fronds. The AgNPs reduced plant growth and the production of chlorophyll pigments a and b; the toxic effects were influenced by exposure media chemistry, and the smaller 10-AgNPs were commonly the most toxic relative to 40-AgNPs. The toxicity pattern was linked to the averagely higher dissolution of 10-AgNPs compared to the larger counterparts. The scanning electron microscopy and X-ray fluorescence analytical techniques were found limited in examining the interaction of the plants with AgNPs at the low exposure concentration used in this study, thus challenging their applicability considering the even lower predicted environmental concentrations AgNPs.

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Green Synthesis and Catalytic Activity of Silver Nanoparticles Based on Piper chaba Stem Extracts

Nanomaterials ◽

10.3390/nano10091777 ◽

2020 ◽

Vol 10 (9) ◽

pp. 1777 ◽

Cited By ~ 2

Author(s):

Md. Mahiuddin ◽

Prianka Saha ◽

Bungo Ochiai

Keyword(s):

Electron Microscopy ◽

Silver Nanoparticles ◽

Green Synthesis ◽

Ftir Spectroscopy ◽

Visual Observation ◽

Face Centered Cubic ◽

X Ray ◽

Vis Spectroscopy ◽

Face Centered ◽

Average Size

A green synthesis of silver nanoparticles (AgNPs) was conducted using the stem extract of Piper chaba, which is a plant abundantly growing in South and Southeast Asia. The synthesis was carried out at different reaction conditions, i.e., reaction temperature, concentrations of the extract and silver nitrate, reaction time, and pH. The synthesized AgNPs were characterized by visual observation, ultraviolet–visible (UV-vis) spectroscopy, dynamic light scattering (DLS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), x-ray diffraction (XRD), energy dispersive x-ray (EDX), and Fourier transform infrared (FTIR) spectroscopy. The characterization results revealed that AgNPs were uniformly dispersed and exhibited a moderate size distribution. They were mostly spherical crystals with face-centered cubic structures and an average size of 19 nm. The FTIR spectroscopy and DLS analysis indicated that the phytochemicals capping the surface of AgNPs stabilize the dispersion through anionic repulsion. The synthesized AgNPs effectively catalyzed the reduction of 4-nitrophenol (4-NP) and degradation of methylene blue (MB) in the presence of sodium borohydride.

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Biophysical and Characterizations of Silver Nanoparticles used as Salmonella typhi Detector

International Journal of Applied Sciences and Biotechnology ◽

10.3126/ijasbt.v2i4.11127 ◽

2014 ◽

Vol 2 (4) ◽

pp. 510-515

Author(s):

Hala Moustafa Ahmed

Keyword(s):

Silver Nanoparticles ◽

Salmonella Typhi ◽

Bacterial Strains ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Vis Spectroscopy ◽

Combined Action ◽

Hog Plum ◽

Transmission Electronmicroscopy

The present study mainly focuses of combined action of Nepali hog plum as well as citrate synthesized silver nanoparticles (AgNPs) and Amikacin, as an antibiotic. The synergistic actions of citrate stabilized silver nanoparticles (AgNPs with chem) were compared with that of Nepali hog plum Choerospondia saxillaris (Lapsi) synthesized silver nanoparticles (AgNPs with plant), together with action of antibiotic onselected bacterial strains of Salmonella typhi. The synthesized AgNPs were characterized through UV-Vis spectroscopy, Transmission electronmicroscopy and X-ray diffraction technique. The size of the synthesized silver nanoparticles was measured by Transmission Electron Microscope (TEM) and X-ray diffraction (XRD).DOI: http://dx.doi.org/10.3126/ijasbt.v2i4.11127 Int J Appl Sci Biotechnol, Vol. 2(4): 510-515

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Ultra-sonication enhanced green synthesis of silver nanoparticles using Barleria buxifolia leaf extract and its possible application

10.21203/rs.3.rs-161063/v1 ◽

2021 ◽

Author(s):

Vanaraj sekar

Keyword(s):

Silver Nanoparticles ◽

Green Synthesis ◽

Leaf Extract ◽

Cancer Cell Line ◽

Xrd Analysis ◽

Blue Dye ◽

Multiple Use ◽

Uniform Size ◽

X Ray ◽

Vis Spectroscopy

Abstract A simple and eco-friendly method for the green synthesis of silver nanoparticles (AgNPs) by ultrasound-assisted strategy using Barleria buxifolia leaf extract as a reducing and capping agent was established in this study. The obtained AgNPs were characterized. UV-vis spectrum, Fourier transform infrared spectroscopy (FTIR), scanning and transmission electron microscopy (SEM and TEM), Energy Dispersive X-Ray Analyzer (EDX), X-ray diffraction, dynamic light scattering (DLS) analysis showed that the obtained AgNPs were mono dispersed spheres with uniform size of 80 nm. UV-vis spectroscopy, FTIR, and XRD analysis indicated that the surface of the obtained AgNPs was covered with organic molecules in plant extracts. The results of ABTS assays showed that high antioxidant activity was seen in the obtained AgNPs. Green synthesized AgNPs showed potent antibacterial and anti-biofilm activity against tested pathogens. Cytotoxicity assay showed that the obtained AgNPs were significantly cytotoxic to cancer cell line (MCF-7). In addition, the AgNPs synthesized in this paper can also photo catalytically degrade methylene blue dye under visible light. The potent bioactivity exhibited by the green synthesized silver nanoparticles leads towards the multiple use as antioxidant, antibacterial, anti-biofilm, cytotoxic as well as photo catalytic agent.

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Anticoagulant, thrombolytic and antibacterial activities of Euphorbia acruensis latex-mediated bioengineered silver nanoparticles

Green Processing and Synthesis ◽

10.1515/gps-2019-0029 ◽

2019 ◽

Vol 8 (1) ◽

pp. 590-599 ◽

Cited By ~ 1

Author(s):

Kaushik Roy ◽

Ambikesh K. Srivastwa ◽

Chandan K. Ghosh

Keyword(s):

Silver Nanoparticles ◽

Analytical Techniques ◽

Antibacterial Activities ◽

Diffusion Method ◽

X Ray Diffraction ◽

Antibacterial Study ◽

X Ray ◽

Transmission Electron ◽

Human Blood Samples ◽

Green Synthesized Silver Nanoparticles

Abstract In this report, we present a simple and unexplored procedure for green synthesis of silver nanoparticles featuring exudation of Euphorbia acruensis along with the study of its antibacterial and anticoagulant properties. Analytical techniques like ultraviolet visible spectroscopy (UV-Vis), X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM) were used to analyse the production, crystallinity and morphology of bio-reduced silver nanoparticles. The antibacterial study was performed by following standard disc diffusion method. Most importantly, the anticoagulant and thrombolytic activities of biogenic silver nanoparticles were evaluated by addition of nanoparticles to human blood samples under practical conditions. These green synthesized silver nanoparticles were found to have potent antibacterial, anticoagulant and thrombolytic properties which make them an attractive choice for future medical applications.

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Exploration of the Antimicrobial and Catalytic Properties of Gold Nanoparticles Greenly Synthesized by Cryptolepis buchanani Roem. and Schult Extract

Journal of Nanomaterials ◽

10.1155/2020/1320274 ◽

2020 ◽

Vol 2020 ◽

pp. 1-11

Author(s):

Kamonpan Wongyai ◽

Phitchayapak Wintachai ◽

Rasimate Maungchang ◽

Parawee Rattanakit

Keyword(s):

Staphylococcus Aureus ◽

Gold Nanoparticles ◽

Analytical Techniques ◽

Average Diameter ◽

Face Centered Cubic ◽

Tem Analysis ◽

X Ray ◽

Transmission Electron ◽

Vis Spectroscopy ◽

Face Centered

A green, simple, and rapid synthesis of gold nanoparticles using plant extract, Cryptolepis buchanani Roem. and Schult, and their applications are first described in this paper. The formation of gold nanoparticles was visually observed by the appearance of a ruby red color, which was further indicated by an absorption peak at 530 nm in UV-Vis spectroscopy. Optimization of reaction parameters for the gold nanoparticles was also investigated. Various analytical techniques were employed as part of the process of characterizing the resulting gold nanoparticles. Fourier transform infrared (FTIR) analysis revealed that the phenol compounds present in the extract were responsible for gold(III) reduction and stabilization of gold nanoparticles. Transmission electron microscopy (TEM) analysis showed that the gold nanoparticles were spherical in shape with an average diameter of 11 nm. Powder X-ray diffraction (XRD) pattern indicated that the green synthesis approach produced highly crystalline, face-centered cubic gold nanoparticles. Energy-dispersive X-ray spectroscopy (EDS) measurements confirmed the presence of elemental gold in the prepared nanoparticles. The negative zeta potential value of gold nanoparticles was found to be -30.28 mV. The green synthesized gold nanoparticles expressed effective antibacterial activity against Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, and Acinetobacter baumannii and exhibited an excellent catalytic property in terms of its reduction ability of methylene blue.

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Biosynthesis, Characterization, and Antidermatophytic Activity of Silver Nanoparticles Using Raamphal Plant (Annona reticulata) Aqueous Leaves Extract

Indian Journal of Materials Science ◽

10.1155/2014/412452 ◽

2014 ◽

Vol 2014 ◽

pp. 1-5 ◽

Cited By ~ 1

Author(s):

P. Shivakumar Singh ◽

G. M. Vidyasagar

Keyword(s):

Silver Nanoparticles ◽

Chemical Compounds ◽

Visual Observation ◽

X Ray Diffraction ◽

Tem Analysis ◽

X Ray ◽

Leaf Aqueous Extract ◽

Vis Spectroscopy ◽

Antidermatophytic Activity ◽

Annona Reticulata

The present work investigated the biosynthesis of silver nanoparticles using Annona reticulata leaf aqueous extract. The biosynthesised silver nanoparticles were confirmed by visual observation and UV-Vis spectroscopy. Appearance of dark brown colour indicated the synthesis of silver in the reaction mixture. The silver nanoparticles were found to be spherical, rod, and triangular in shape with variable size ranging from 23.84 to 50.54 nm, as evident by X-ray diffraction studies, TEM. The X-ray diffraction studies, energy dispersive X-ray analysis, and TEM analysis indicate that the particles are crystalline in nature. The nanoparticles appeared to be associated with some chemical compounds which possess hydroxyl and carbonyl groups, confirmed by FTIR. This is the first and novel report of silver nanoparticles synthesised from Annona reticulata leaves extract and their antidermatophytic activity.

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Heteroagglomeration of nanosilver with colloidal SiO2 and clay

Environmental Chemistry ◽

10.1071/en16070 ◽

2017 ◽

Vol 14 (1) ◽

pp. 1 ◽

Cited By ~ 4

Author(s):

Sébastien Maillette ◽

Caroline Peyrot ◽

Tapas Purkait ◽

Muhammad Iqbal ◽

Jonathan G. C. Veinot ◽

...

Keyword(s):

Silver Nanoparticles ◽

Polyacrylic Acid ◽

Natural Waters ◽

Colloidal Particles ◽

Colloidal Stability ◽

Analytical Techniques ◽

Dark Field ◽

Correlation Spectroscopy ◽

Colloidal Clay ◽

High Concentrations

Environmental contextThe fate of nanomaterials in the environment is related to their colloidal stability. Although numerous studies have examined their homoagglomeration, their low concentration and the presence of high concentrations of natural particles implies that heteroagglomeration rather than homoagglomeration is likely to occur under natural conditions. In this paper, two state-of-the art analytical techniques were used to identify the conditions under which nanosilver was most likely to form heteroagglomerates in natural waters. AbstractThe environmental risk of nanomaterials will depend on their persistence, mobility, toxicity and bioaccumulation. Each of these parameters is related to their fate (especially dissolution, agglomeration). The goal of this paper was to understand the heteroagglomeration of silver nanoparticles in natural waters. Two small silver nanoparticles (nAg, ~3nm; polyacrylic acid- and citrate-stabilised) were covalently labelled with a fluorescent dye and then mixed with colloidal silicon oxides (SiO2, ~18.5nm) or clays (~550nm SWy-2 montmorillonite). Homo- and heteroagglomeration of the nAg were first studied in controlled synthetic waters that were representative of natural fresh waters (50μg Ag L–1; pH 7.0; ionic strength 10–7 to 10–1 M Ca) by following the sizes of the nAg by fluorescence correlation spectroscopy. The polyacrylic acid-coated nanosilver was extremely stable under all conditions, including in the presence of other colloids and at high ionic strengths. However, the citrate-coated nanosilver formed heteroaggregates in presence of both colloidal SiO2 and clay particles. Nanoparticle surface properties appeared to play a key role in controlling the physicochemical stability of the nAg. For example, the polyacrylic acid stabilized nAg-remained extremely stable in the water column, even under conditions for which surrounding colloidal particles were agglomerating. Finally, enhanced dark-field microscopy was then used to further characterise the heteroagglomeration of a citrate-coated nAg with suspensions of colloidal clay, colloidal SiO2 or natural (river) water.

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Biosynthesis and Characterization of Extracellular Silver Nanoparticles from Streptomyces aizuneusis: Antimicrobial, Anti Larval, and Anticancer Activities

Molecules ◽

10.3390/molecules27010212 ◽

2021 ◽

Vol 27 (1) ◽

pp. 212

Author(s):

Hemmat M. Abd-Elhady ◽

Mona A. Ashor ◽

Abdelkader Hazem ◽

Fayez M. Saleh ◽

Samy Selim ◽

...

Keyword(s):

Silver Nanoparticles ◽

Human Lung ◽

Spherical Shape ◽

Antimicrobial Activities ◽

Anticancer Activities ◽

X Ray ◽

Transmission Electron ◽

Vis Spectroscopy ◽

Human Lung Carcinoma

The ability of microorganisms to reduce inorganic metals has launched an exciting eco-friendly approach towards developing green nanotechnology. Thus, the synthesis of metal nanoparticles through a biological approach is an important aspect of current nanotechnology. In this study, Streptomyces aizuneusis ATCC 14921 gave the small particle of silver nanoparticles (AgNPs) a size of 38.45 nm, with 1.342 optical density. AgNPs produced by Streptomyces aizuneusis were characterized by means of UV-VIS spectroscopy and transmission electron microscopy (TEM). The UV-Vis spectrum of the aqueous solution containing silver ion showed a peak between 410 to 430. Moreover, the majority of nanoparticles were found to be a spherical shape with variables between 11 to 42 nm, as seen under TEM. The purity of extracted AgNPs was investigated by energy dispersive X-ray analysis (EDXA), and the identification of the possible biomolecules responsible for the reduction of Ag+ ions by the cell filtrate was carried out by Fourier Transform Infrared spectrum (FTIR). High antimicrobial activities were observed by AgNPs at a low concentration of 0.01 ppm, however, no deleterious effect of AgNPs was observed on the development and occurrence of Drosophila melanogaster phenotype. The highest reduction in the viability of the human lung carcinoma and normal cells was attained at 0.2 AgNPs ppm.

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