scholarly journals Preparation of Silver Nanoparticles in a Plasma-Liquid System in the Presence of PVA: Antimicrobial, Catalytic, and Sensing Properties

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Margarita I. Skiba ◽  
Victoria I. Vorobyova ◽  
Iryna V. Kosogina
Keyword(s):  
Polyvinyl Alcohol ◽  
Catalytic Reduction ◽  
Average Particle Size ◽  
Liquid System ◽  
Localized Surface Plasmon ◽  
Average Particle ◽  
Technological Parameters ◽  
Short Term ◽  
Ag Nps ◽  
Sem Images

The preparation of stabilized silver nanodispersions under the action of short-term plasma discharge using a polyvinyl alcohol stabilizer (polyvinyl alcohol (PVA)) was investigated. The influence of the basic technological parameters such as initial Ag+ concentration, PVA concentration, and process duration on the formation of nanoparticles and their characteristics (size and stability) were determined. The UV-Vis spectra showed the localized surface plasmon resonance at wavelengths of 400–420 nm. The SEM images showed that the shape of Ag NPs is spherical with an average particle size up to 30 nm. Ag NPs were used as a catalyst for the reduction of 4-nitrophenol (4-NP). The effect of the concentration of PNP and catalyst dosage on the value of apparent rate constant (kapp) for catalytic reduction of 4-NP in the presence of Ag NPs was investigated by means of UV-Vis spectrophotometry. The antimicrobial activity of Ag nanoparticles was investigated against yeast and Escherichia coli. The colorimetric sensor studies of plasma synthesized Ag NPs showed selective sensing of the potentially hazardous Hg2+ ion in water.

scholarly journals Electrospun synthesis of silver/poly (vinyl alcohol) nano-fibers: investigation antibacterial activity and flame retardant property

2021 ◽  
Author(s):  
Sara Azarakhsh ◽  
Hamed Bahiraei ◽  
Gholamhosain Haidari ◽  
Davood Ghanbar
Keyword(s):  
Polyvinyl Alcohol ◽  
Flame Retardant ◽  
Ag Nanoparticles ◽  
Average Particle Size ◽  
Water Soluble ◽  
Poly Vinyl Alcohol ◽  
Average Particle ◽  
Sem Images ◽  
Water Soluble Polymer ◽  
Nano Fiber

Abstract Polyvinyl alcohol (PVA) and Ag nanoparticles-embedded polyvinyl alcohol (Ag/PVA) nano-fibers have been synthesized successfully via the electro-spinning technique at room temperature. XRD patterns confirmed the presence of Ag nanoparticles in the electro-spinning PVA nano-fibers. FE-SEM images displayed that silver nanoparticles with an average particle size of 32 nm are uniformly dispersed in PVA nano-fibers. Also, the average diameter of Ag/PVA nano-fibers was estimated to be 142 nm. The EDX analysis of Ag/PVA nano-fiber determined the aggregation of Ag nanoparticles in the range of polymer nano-fibers. The antibacterial property of Ag/PVA nano-fiber for inhibition of Escherichia coli (E-coli) growth was approved. Since polyvinyl alcohol is a biocompatible and water-soluble polymer, it can be considered as unique candidate for the preparation of wound dressing nano-fibers. It is also found that the nontoxic nanostructures can appropriately enhance both flame retardant and thermal stability properties of the Ag/PVA matrix. These results show that the Ag/PVA nano-fibers may find practical applications as self-reinforced medical devices and tissue-engineering scaffolds.

scholarly journals Fabrication of Ag and Ni Nanocatalyst with Enhanced Efficiency

2015 ◽  
Vol 2015 ◽  
pp. 1-4 ◽  
Author(s):  
Tajamal Hussain ◽  
Mira Tul Zubaida Butt ◽  
Mirza Nadeem Ahmed ◽  
Muhammad Hamid Raza ◽  
Zahoor Hussain Farooqi ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Catalytic Activity ◽  
Chemical Reduction ◽  
Average Particle Size ◽  
Blue Dye ◽  
Average Particle ◽  
Ag Nps ◽  
Sem Images ◽  
First Case ◽  
Supported Ni

Metal nanoparticles (NPs) have received significant attention in last decade because of their unique properties. In this work, two different metal NPs have been prepared and their catalytic activities are compared with conventional catalyst. In first case, Ag NPs were synthesized by chemical reduction method in ethanolic medium. Synthesized Ag NPs were characterized by scanning electron microscope (SEM) images which indicated an average particle size of Ag around 250 nm. The catalytic activity of Ag NPs was investigated for the oxidative mineralization of methylene blue dye. Comparative studies suggested that Ag NPs possess enhanced catalytic activity compared to bulk Ag. In second approach, supported Ni NPs were fabricated using Al2O3as supporting surface; that is, Ni NPs get adsorbed on Al2O3through in situ reduction reaction. Oxidative degradation of methylene blue indicated that catalytic activity of supported Ni/Al2O3is about five times higher than simple Ni as catalyst.

scholarly journals Effect of adding TiO2 nanoparticles on the SEM morphology and mechanical properties of conventional heat-cured acrylic resin

2019 ◽  
Vol 13 (3) ◽  
pp. 234-240
Author(s):  
Elnaz Moslehifard ◽  
Mahmood Robati Anaraki ◽  
Saeed Shirkavand
Keyword(s):  
Impact Strength ◽  
Tio2 Nanoparticles ◽  
Cross Sections ◽  
Average Particle Size ◽  
Acrylic Resin ◽  
Mechanical Tests ◽  
Average Particle ◽  
Sem Images ◽  
Tio2 Nps ◽  
The Impact

Background. The current study evaluated the compressive, flexural and impact strengths of heat-cured acrylic resins reinforced by TiO2 nanoparticles (NPs). Methods. TiO2 NPs were provided and characterized using scanning electron microscopy (SEM) to determine their morphology and crystalline structure. For three mechanical tests, 12 acrylic resin groups (n=9), totaling 108 specimens, were prepared using a special mold for each test, with TiO2 nanoparticle contents of 0, 0.5, 1 or 2 wt% in different groups. After curing, the compressive, flexural and impact strengths of the specimens were examined according to ISO 1567. Results. In the SEM and XRD study of TiO2 NPs, anatase was identified as the major crystalline phase followed by rutile (average particle size: 20.4 nm). SEM images showed that the nanocomposite with 1 wt% NPs had a more homogenized blend. 1 wt% TiO2 nanocomposite exhibited a higher, but non-significant, impact strength compared to the controls. ANOVA showed significant differences in the impact and flexural strengths between nanocomposites with various contents of TiO2 NPs. Conclusion. The nanocomposite with 1 wt% TiO2 NPs exhibited fewer micro-pores and micro-cracks in the SEM cross-sections. A non-significant increase was also observed in the impact strength with TiO2 NPs at 1 wt%. Further increase in TiO2 NPs decreased both the impact and flexural strengths. The compressive strength of the heat-cured acrylic resin was not affected by the incorporation of NPs.

scholarly journals Effect of Nanosized Colloidal Copper on Cotton Fabric

2010 ◽  
Vol 5 (3) ◽  
pp. 155892501000500 ◽  
Author(s):  
D.P. Chattopadhyay ◽  
B.H. Patel
Keyword(s):  
Particle Size ◽  
Cotton Fabric ◽  
Colloidal Solution ◽  
Chemical Reduction ◽  
Average Particle Size ◽  
Particle Size Analysis ◽  
Nano Particles ◽  
Size Analysis ◽  
Average Particle ◽  
Sem Images

This research deals with the synthesis of nanosized copper as colloidal solution and its application to cotton fabric. Copper nano colloids were prepared by chemical reduction of copper salt using sodium borohydride as reducing agent in presence of tri-sodium citrate. The size and size distribution of the particles were examined by particle size analyzer and the morphology of the synthesized particles was examined by SEM and AFM techniques. X-ray fluorescence spectroscopy detected the presence of copper in the treated fabric. The results of particle size analysis showed that the average particle size varied from 60 nm to 100 nm. The nano copper treated cotton was subjected to soil burial test for the assessment of its resistance towards microbial attack. SEM images of treated fabric indicate copper nano particles are well dispersed on the surface of the specimens. The treatments of nano copper colloidal solution on cotton not only improve its antimicrobial efficiency but also influenced the tensile strength of the fabric sample positively. The treatment was found to enhance the color depth and fastness properties of direct dyed cotton fabric samples.

Catalytic Reduction of Nitrobenzene Using Silver Nanoparticles Embedded Calcium Alginate Film

2019 ◽  
Vol 19 (11) ◽  
pp. 7487-7492 ◽  
Author(s):  
Supriya ◽  
Jayanta Kumar Basu ◽  
Sonali Sengupta
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silver Nanoparticles ◽  
Sodium Borohydride ◽  
Calcium Alginate ◽  
Catalytic Reduction ◽  
Average Particle Size ◽  
Catalyst Loading ◽  
Average Particle ◽  
Transmission Electron

Synthesis of silver nanoparticles embedded on calcium alginate film and the catalytic property of this film in the reduction of nitrobenzene with sodium borohydride are demonstrated in this work. Natural polymer alginate acts as effective reducing and stabilizing agent in synthesis of silver nanoparticles. Effect of different parameters on the preparation of silver nanoparticles, such as, temperature, concentration of silver precursor and heating time was investigated. As-prepared silver nanoparticles were characterized by transmission electron microscopy, scanning electron microscopy, UV-Vis spectrometry, and atomic absorption spectrometry. Transmission electron microscopy analysis con-firms the formation of silver nanoparticles with particles size range of 3–19 nm and average particle size was found to be 10±4 nm. Effect of concentration of nitrobenzene and sodium borohydride, catalyst loading and temperature on the catalytic reduction of nitrobenzene was studied. Reusability of catalyst was examined in this reduction reaction and the catalyst shows good activity up to 10th run.

scholarly journals Olive Leaves as Biotemplates for Enhanced Solar-Light Harvesting by a Titania-Based Solid

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1057
Author(s):  
Jesús Hidalgo-Carrillo ◽  
Juan Martín-Gómez ◽  
M. Carmen Herrera-Beurnio ◽  
Rafael C. Estévez ◽  
Francisco J. Urbano ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Average Particle Size ◽  
Solar Irradiation ◽  
Bet Surface Area ◽  
Resonance Spectroscopy ◽  
Average Particle ◽  
Olive Leaves ◽  
Sem Images ◽  
X Ray

Olive leaves (by-product from olive oil production in olive mills) were used as biotemplates to synthesize a titania-based artificial olive leaf (AOL). Scanning electron microscopy (SEM) images of AOL showed the successful replication of trichomes and internal structure channels present in olive leaves. The BET surface area of AOL was 52 m2·g−1. X-ray diffraction (XRD) and Raman spectra revealed that the resulting solid was in the predominantly-anatase crystalline form (7.5 nm average particle size). Moreover, the synthesis led to a red-shift in light absorption as compared to reference anatase (gap energies of 2.98 and 3.2 eV, respectively). The presence of surface defects (as evidenced by X-ray photoelectron spectroscopy, XPS, and electron paramagnetic resonance spectroscopy, EPR) and doping elements (e.g., 1% nitrogen, observed by elemental analysis and XPS) could account for that. AOL was preliminarily tested as a catalyst for hydrogen production through glycerol photoreforming and exhibited an activity 64% higher than reference material Evonik P25 under solar irradiation and 144% greater under ultraviolet radiation (UV).

Synthesis of Gamma-Alumina Nanopowders Using Waste Metal Aluminum and Stability Surfactants

2019 ◽  
Vol 19 (02) ◽  
pp. 1950014
Author(s):  
Sabereh Nazari ◽  
Sadegh Nazari ◽  
Fariba Mansourizadeh ◽  
Gholamreza Karimi
Keyword(s):  
Particle Size ◽  
Polyethylene Glycol ◽  
Polyvinyl Alcohol ◽  
Specific Surface ◽  
Pore Volume ◽  
Average Particle Size ◽  
Average Crystallite Size ◽  
Average Particle ◽  
Gamma Alumina ◽  
Metal Aluminum

In this study, high purity gamma-alumina nanopowders with crystalline structures have been prepared via a sol–gel process by waste metal aluminum, HCl, NaOH, Polyethylene glycol (PEG) and polyvinyl alcohol (PVA). Polyethylene glycol and polyvinyl alcohol have been used as stabilizing agents. The characterization of the samples has been performed utilizing XRD, FTIR, SEM, N2 adsorption/desorption techniques. Prepared samples of gamma-alumina at 800∘C with PEG has an average crystallite size of 2.58[Formula: see text]nm, average particle size of 21[Formula: see text]nm, specific surface area (SSA) of 65.55[Formula: see text]m2/g, and pore volume of [Formula: see text]0.06[Formula: see text]cm3/g. The average crystallite size of 3.07[Formula: see text]nm, average particle size of 31[Formula: see text]nm, specific surface area of 131.25[Formula: see text]m2/g, and pore volume of [Formula: see text]0.14[Formula: see text]cm3/g, were obtained using PVA surfactant.

The Utilization of Ground Tire Rubber as Ion Exchange Materials

2018 ◽  
Vol 382 ◽  
pp. 352-356 ◽  
Author(s):  
Supitcha Rungrodnimitchai ◽  
Sirinapa Mayod ◽  
Sutamma Tanasarn
Keyword(s):  
Reaction Time ◽  
Ion Exchange ◽  
Average Particle Size ◽  
Average Particle ◽  
Sem Images ◽  
Carboxyl Content ◽  
Tire Rubber ◽  
Ground Tire Rubber ◽  
Chemically Modified ◽  
Ft Ir

In this study, ground tire rubber (R-GTR) with the average particle size of 456 µm was chemically modified to produce modified ground tire rubber (M-GTR) that can work as ion exchange materials. The modification was performed by oxidation reaction. The ground tire rubber was oxidized at the range of temperature from 20 to 40๐C for 48, 72 and 96 hours by a mixture of the HNO3/H3PO4/NaNO2system. The HNO3/H3PO4ratio was 1:3 and the concentration of NaNO2was 1.4% w/v. FT-IR revealed that the carboxyl group or the carbonyl group was successfully introduced into the modified ground tire rubber and SEM images demonstrated that the porosity of modified ground tire rubber increased. The results of the modified ground tire rubber showed that the carboxyl content increased with an increase of reaction time while %yield decreased with an increase of reaction time. The optimum condition for modification was the reaction at 30๐C for 96 hours.

scholarly journals Microwave solvothermal synthesis and characterization of manganese-doped ZnO nanoparticles

2016 ◽  
Vol 7 ◽  
pp. 721-732 ◽  
Author(s):  
Jacek Wojnarowicz ◽  
Roman Mukhovskyi ◽  
Elzbieta Pietrzykowska ◽  
Sylwia Kusnieruk ◽  
Jan Mizeracki ◽  
...  
Keyword(s):  
Particle Size ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Solvothermal Synthesis ◽  
Web Application ◽  
Zinc Acetate Dihydrate ◽  
Average Particle Size ◽  
Average Particle ◽  
Sem Images

Mn-doped zinc oxide nanoparticles were prepared by using the microwave solvothermal synthesis (MSS) technique. The nanoparticles were produced from a solution of zinc acetate dihydrate and manganese(II) acetate tetrahydrate using ethylene glycol as solvent. The content of Mn2+ in Zn1− x Mn x O ranged from 1 to 25 mol %. The following properties of the nanostructures were investigated: skeleton density, specific surface area (SSA), phase purity (XRD), lattice parameters, dopant content, average particle size, crystallite size distribution, morphology. The average particle size of Zn1− x Mn x O was determined using Scherrer’s formula, the Nanopowder XRD Processor Demo web application and by converting the specific surface area results. X-ray diffraction of synthesized samples shows a single-phase wurtzite crystal structure of ZnO without any indication of additional phases. Spherical Zn1− x Mn x O particles were obtained with monocrystalline structure and average particle sizes from 17 to 30 nm depending on the content of dopant. SEM images showed an impact of the dopant concentration on the morphology of the nanoparticles.

scholarly journals Biosynthesis and Characterization of Silver Nanoparticles from Bitter Melon (Momordica charantia) Fruit and Seed Extract and their Antimicrobial Activity

2021 ◽  
Vol 2 (1) ◽  
pp. 1-11
Author(s):  
Umme Ruman ◽  
Poonah Kia
Keyword(s):  
Silver Nanoparticles ◽  
Average Particle Size ◽  
Antibacterial Properties ◽  
Seed Extract ◽  
Food Preservation ◽  
Momordica Charantia ◽  
Average Particle ◽  
Ag Nps ◽  
Fruit Extract ◽  
Biotechnological Approach

Momordica charantia is a phenolic rich vegetable. In this study, the fruits and seeds extract of M. charantia were used to synthesize silver nanoparticles (Ag NPs) using biotechnological approach. Structural, morphological, and antimicrobial properties of the synthesized Ag-NPs were characterized using UV/Vis Spectrophotometry, Dynamic Light Scattering (DLS), High Resolution Transmission Electronics Microscopy (HRTEM), Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared Spectroscopy (FTIR) and X-Ray diffraction (XRD). In DLS, the average particle size of Ag-NPs was found 17.5 ± 2.1 nm and 18.3 ± 1.9 nm using seed and fruit extract, respectively. HRTEM has revealed their spherical structure for both seed and fruit extract of M. charantia. FESEM images found Ag-NPs with the size between ~20 and ~35 nm. The Ag NPs exhibited Surface Plasmon Resonance (SPR) centered at 405 nm for seed extract and 402 nm for fruit extract using a UV–visible spectrophotometer. FT-IR results showed phenolic and carbohydrate compounds involved in the synthesis of the Ag NPs. Furthermore, the synthesized Ag NPs has found highly rich in antibacterial properties against Escherichia coli and Pseudomonas aeruginosa bacterium. Thus, bioconversion of Ag NPs by M. charantia could be employed as a potential antibacterial source to eliminate pathogenic microorganisms from agricultural and food preservation industry.

Sign in / Sign up

Export Citation Format

Share Document