scholarly journals Bioactive Nano-Composite Multifilament Yarns

2012 ◽  
Vol 7 (1) ◽  
pp. 155892501200700 ◽  
Author(s):  
Mohammad Esmail Yazdanshenas ◽  
Rogheih Damerchely ◽  
Abo Saied Rashidi ◽  
Ramin Khajavi
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Inductively Coupled Plasma ◽  
Melt Spinning ◽  
Antimicrobial Properties ◽  
Physical And Mechanical Properties ◽  
Nylon 6 ◽  
Antimicrobial Activities ◽  
Scanning Calorimetry ◽  
Inductively Coupled

Physical, mechanical and antimicrobial properties of nylon 6 (polycaprolactam) doped with different amounts of silver nanoparticles were investigated in this study. Two series of filament yarns counts (20 and 70 Denier) were produced by melt spinning method with different amounts of silver nanoparticles contents (0, 0.5, 1 and 4 wt%). Elemental analysis of silver and titanium dioxide (present in polymer as delustering agent) was carried out by energy dispersive X-ray (EDX) and inductively coupled plasma mass spectrometry (ICP-MS) methods. Tensile testing, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and differential scanning calorimetry (DSC) were used to characterize the yarns. Antimicrobial activities were quantitatively evaluated against Escherichia Coli (gram-negative) and Staphylococcus Aureus (gram-positive) bacteria. The doped nylon 6 fibers showed a well dispersed distribution of silver nanoparticles. Yarns with 0.5–1.0 wt% of silver nanoparticle content were found to have improved physical and mechanical properties, as well as, significant antimicrobial activity.

scholarly journals Rowan Berries: A Potential Source for Green Synthesis of Extremely Monodisperse Gold and Silver Nanoparticles and Their Antimicrobial Property

Pharmaceutics ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 82
Author(s):  
Priyanka Singh ◽  
Ivan Mijakovic
Keyword(s):  
Electron Microscopy ◽  
Mass Spectrometry ◽  
Silver Nanoparticles ◽  
Inductively Coupled Plasma ◽  
Antimicrobial Property ◽  
Gold And Silver Nanoparticles ◽  
Inductively Coupled ◽  
Flight Mass Spectrometry ◽  
Vis Spectroscopy ◽  
Plasma Mass Spectrometry

Rowanberries (Sorbus aucuparia) are omnipresent in Europe. The medicinal importance of rowanberries is widely known and corresponds to the active ingredients present in the fruits, mainly polyphenols, carotenoids, and organic acids. In the current study, we explored rowanberries for the reduction of gold and silver salts into nanoparticles. Rowanberries-mediated gold nanoparticles (RB-AuNPs) formed within 5 s at room temperature, and silver nanoparticles (RB-AgNPs) formed in 20 min at 90 °C. The produced nanoparticles were thoroughly characterized by UV-Vis spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray (EDX), transmission electron microscopy (TEM), dynamic light scattering (DLS), single-particle inductively coupled plasma–mass spectrometry (sp-ICP-MS), thermogravimetric analysis (TGA), Fourier transform-infrared spectroscopy (FT-IR) and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF). The characterization confirmed that the nanoparticles are highly monodisperse, spherical, stable over long periods, and exhibit a high negative zeta potential values. The produced RB-AuNPs and RB-AgNPs were 90–100 nm and 20–30 nm in size with a thick biological corona layer surrounding them, providing extreme stability but lowering the antimicrobial activity. The antimicrobials study of RB-AgNPs revealed that the nanoparticles have antimicrobial potential with an MBC value of 100 µg/mL against P. aeruginosa and 200 µg/mL against E. coli.

scholarly journals Silver nanoparticles nucleated in NaOH-treated halloysite: a potential antimicrobial material

2021 ◽  
Vol 12 ◽  
pp. 798-807
Author(s):  
Yuri B Matos ◽  
Rodrigo S Romanus ◽  
Mattheus Torquato ◽  
Edgar H de Souza ◽  
Rodrigo L Villanova ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Antimicrobial Properties ◽  
X Ray Diffraction ◽  
Ag Nps ◽  
Scanning Calorimetry ◽  
Medical Treatments ◽  
X Ray ◽  
E Coli ◽  
Transmission Electron

Despite all recent advances in medical treatments, infectious diseases remain dangerous. This has led to intensive scientific research on materials with antimicrobial properties. Silver nanoparticles (Ag-NPs) are a well-established solution in this area. The present work studied the nucleation of silver on halloysite substrates modified by chemical treatment with NaOH. The resulting stabilized Ag-NPs were characterized by X-ray diffraction, transmission electron microscopy, and energy-dispersive X-ray spectroscopy. The nucleation was characterized by thermogravimetric analysis and differential scanning calorimetry. The antimicrobial properties of the Ag-NPs were investigated against E. coli and S. aureus. The potential of the Ag-NPs for industrial application was tested by dispersing them into low-density polyethylene. The importance of the chemical affinity between matrix and additive was tested through coating the Ag-NPs with dodecanethiol, a non-polar surfactant. The resulting composites were characterized by scanning electron microscopy and in terms of surface antimicrobial activity. The results demonstrate that the Ag-NPs synthesized in this work are indeed antimicrobial, and that it is possible to imbue a polymeric matrix with the antimicrobial properties of Ag-NPs.

scholarly journals Silver nanoparticles nucleated in NaOH treated halloysite: a potential antimicrobial material.

2021 ◽  
Author(s):  
Yuri B Matos ◽  
Rodrigo S Romanus ◽  
Mattheus Torquato ◽  
Edgar H de Souza ◽  
Rodrigo L Villanova ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Antimicrobial Properties ◽  
X Ray Diffraction ◽  
Ag Nps ◽  
Scanning Calorimetry ◽  
Medical Treatments ◽  
X Ray ◽  
E Coli ◽  
Transmission Electron

Despite all recent advances in medical treatments, infectious diseases remain dangerous. This scenario has led to intense scientific research on materials with antimicrobial properties. Silver nanoparticles (Ag-NPs) are a well established solution in this area. The present work studied the nucleation of silver in halloysite substrates (HNT) modified by a NaOH chemical treatment. The resulting stabilized Ag-NPs were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and energy dispersive x-ray spectroscopy (EDS). The nucleation was characterized by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Ag-NPs antimicrobial properties were investigated against \textit{E. coli} and \textit{S. aureus}. The potential of Ag-NPs for industrial application was tested by dispersing them into low density polyethylene (LDPE). The importance of the chemical affinity between matrix and additive was tested coating Ag-NPs with dodecanethiol, a non-polar surfactant. The resulting composites were characterized by scanning electron microscopy (SEM) and in terms of surface antimicrobial activity. The results demonstrate that Ag-NPs synthesized in this work are indeed antimicrobial, and that it is possible to imbue a polymeric matrix with the Ag-NPs antimicrobial properties.

scholarly journals Pd Nanoparticles Stabilized on the Cross-Linked Melamine-Based SBA-15 as a Catalyst for the Mizoroki–Heck Reaction

2021 ◽  
Author(s):  
Ayat Nuri ◽  
Abolfazl Bezaatpour ◽  
Mandana Amiri ◽  
Nemanja Vucetic ◽  
Jyri-Pekka Mikkola ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Inductively Coupled Plasma ◽  
High Surface ◽  
High Surface Area ◽  
Coupling Reaction ◽  
Pd Nanoparticles ◽  
Significant Activity ◽  
Inductively Coupled ◽  
Transmission Electron ◽  
Ft Ir

AbstractMesoporous SBA-15 silicate with a high surface area was prepared by a hydrothermal method, successively modified by organic melamine ligands and then used for deposition of Pd nanoparticles onto it. The synthesized materials were characterized with infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), nitrogen physisorption, scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), nuclear magnetic resonance (NMR) and inductively coupled plasma (ICP-OES). The catalyst was effectively used in the Mizoroki–Heck coupling reaction of various reactants in the presence of an organic base giving the desired products in a short reaction time and with small catalysts loadings. The reaction parameters such as the base type, amounts of catalyst, solvents, and the temperature were optimized. The catalyst was easily recovered and reused at least seven times without significant activity losses. Graphic Abstract

scholarly journals Estimation of the Uncertainties Related to the Measurement of the Size and Quantities of Individual Silver Nanoparticles in Confectionery

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2677 ◽  
Author(s):  
Nadia Waegeneers ◽  
Sandra De Vos ◽  
Eveline Verleysen ◽  
Ann Ruttens ◽  
Jan Mast
Keyword(s):  
Silver Nanoparticles ◽  
Sample Preparation ◽  
Measurement Uncertainty ◽  
Inductively Coupled Plasma ◽  
Food Additives ◽  
Data Interpretation ◽  
Background Concentration ◽  
Inductively Coupled ◽  
Validation Parameters ◽  
Plasma Mass Spectrometry

E174 (silver) is a food additive that may contain silver nanoparticles (AgNP). Validated methods are needed to size and quantify these particles in a regulatory context. However, no validations have yet been performed with food additives or real samples containing food additives requiring a sample preparation step prior to analysis. A single-particle inductively coupled plasma mass spectrometry (spICP-MS) method was developed and validated for sizing and quantifying the fraction of AgNP in E174 and in products containing E174, and associated uncertainties related to sample preparation, analysis and data interpretation were unraveled. The expanded measurement uncertainty for AgNP sizing was calculated to be 16% in E174-containing food products and increased up to 23% in E174 itself. The E174 food additives showed a large silver background concentration combined with a relatively low number of nanoparticles, making data interpretation more challenging than in the products. The standard uncertainties related to sample preparation, analysis, and challenging data interpretation were respectively 4.7%, 6.5%, and 6.0% for triplicate performances. For a single replicate sample, the uncertainty related to sample preparation increased to 6.8%. The expanded measurement uncertainty related to the concentration determination was 25–45% in these complex samples, without a clear distinction between additives and products. Overall, the validation parameters obtained for spICP-MS seem to be fit for the purpose of characterizing AgNP in E174 or E174-containing products.

Synthesis, characterization and application of green seaweed mediated silver nanoparticles (AgNPs) as antibacterial agents for water disinfection

2018 ◽  
Vol 78 (1) ◽  
pp. 235-246 ◽  
Author(s):  
D. Dixit ◽  
D. Gangadharan ◽  
K. M. Popat ◽  
C. R. K. Reddy ◽  
M. Trivedi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Inductively Coupled Plasma ◽  
Antibacterial Agents ◽  
Bacterial Count ◽  
Water Disinfection ◽  
Bacterial Strains ◽  
Vis Spectroscopy ◽  
Green Seaweed

Abstract A simple and eco-friendly method for the synthesis of hybrid bead silver nanoparticles (AgNPs) employing the aqueous extract derived from natural and renewable source namely tropical benthic green seaweed Ulva flexuosa was developed. This route involves the reduction of Ag+ ions anchored onto macro porous methacrylic acid copolymer beads to AgNPs for employing them as antibacterial agents for in vitro water disinfection. The seaweed extract itself acts as a reducing and stabilizing agent and requires no additional surfactant or capping agent for forming the AgNPs. The nanoparticles were analyzed using high-resolution transmission electron microscopy, UV–Vis spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray analysis and inductively coupled plasma optical emission spectroscopy. The study elucidates that such biologically synthesized AgNPs exhibit potential antibacterial activity against two Gram positive (Bacillus subtilis, Staphylococcus aureus) and two Gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacterial strains tested. The bacterial count in treated water was reduced to zero for all the strains. Atomic force microscopy was performed to confirm the pre- and post-state of the bacteria with reference to their treatment with AgNPs. Attributes like facile environment-friendly procedure, stability and high antibacterial potency propel the consideration of these AgNPs as promising antibacterial entities.

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