Aging of silver nanocolloids in sunlight: particle size has a major influence

2018 ◽  
Vol 15 (7) ◽  
pp. 450 ◽  
Author(s):  
Sylvie Motellier ◽  
Nathalie Pélissier ◽  
Jean-Gabriel Mattei
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Inductively Coupled Plasma ◽  
Environmental Fate ◽  
Major Influence ◽  
Ag Nps ◽  
Sunlight Irradiation ◽  
Physical Fractionation ◽  
Icp Ms ◽  
Primary Particles

Environmental contextTransformation of silver nanoparticles in the environment is an important issue because the form they take directly influences what effect they have. We show that the size of the primary particles of silver nanosuspensions is a major factor determining their evolution under sunlight irradiation (dissolution, formation of nanoseeds and nanoprisms, agglomeration). The persistence of nano-sized silver particles after exposure to sunlight irradiation implies that their ecotoxicological impact will likely last well beyond their introduction in the environment. AbstractThe environmental fate of silver nanoparticles (Ag NPs) is a serious cause for concern with regard to their ecotoxicity. In this study, an aging scenario intended to evaluate the effect of sunlight on three Ag NP suspensions of various particle size was assessed. Suspensions of citrate-stabilised Ag NPs of 20, 60, and 100 nm diameter were aged for a week in a climatic chamber under controlled temperature (40 °C) and irradiation (1.44 W m−2 at 420 nm). The suspensions were analysed by asymmetric flow field flow fractionation – inductively coupled plasma mass spectrometry (AF4-ICP-MS), dynamic light scattering (DLS) and transmission electron microscopy (TEM). The AF4-ICP-MS monitoring showed that only a small fraction (10 % at most) of the primary 20 nm particles are converted into multi-faceted particles. Larger particles undergo shape modifications correlated with dissolution (60 nm Ag NPs) and aggregation (100 nm Ag NPs) processes. Silicate structures – supposedly originating from the glassware degradation – stabilise the primary particles. The occurrence of smaller Ag seeds, also associated with silicates, was revealed and quantified by AF4-ICP-MS and confirmed by TEM. The physical fractionation of the particles according to their size provided by AF4, together with the quantitative analysis provided by ICP-MS, helped to determine the role of size in the fate of silver nanoparticles under sunlight exposure.

scholarly journals Iodine and bromine speciation in snow and the effect of orographically induced precipitation

2007 ◽  
Vol 7 (10) ◽  
pp. 2661-2669 ◽  
Author(s):  
B. S. Gilfedder ◽  
M. Petri ◽  
H. Biester
Keyword(s):  
Inductively Coupled Plasma ◽  
Major Influence ◽  
Horizontal Distance ◽  
Aerosol Formation ◽  
Terrestrial Environment ◽  
Total Iodine ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Two Samples ◽  
Snow Crystals

Abstract. Iodine is an essential trace element for all mammals and may also influence climate through new aerosol formation. Atmospheric bromine cycling is also important due to its well-known ozone depletion capabilities. Despite precipitation being the ultimate source of iodine in the terrestrial environment, the processes effecting its distribution, speciation and transport are relatively unknown. The aim of this study was to determine the effect of orographically induced precipitation on iodine concentrations in snow and also to quantify the inorganic and organic iodine and bromine species. Snow samples were collected over an altitude profile (~840 m) from the northern Black Forest and were analysed by ion-chromatography - inductively coupled plasma mass spectrometry (IC-ICP-MS) for iodine and bromine species and trace metals (ICP-MS). All elements and species concentrations in snow showed significant (r2>0.65) exponential decrease relationships with altitude despite the short (5 km) horizontal distance of the transect. In fact, total iodine more than halved (38 to 13 nmol/l) over the 840 m height change. The results suggest that orographic lifting and subsequent precipitation has a major influence on iodine concentrations in snow. This orographically induced removal effect may be more important than lateral distance from the ocean in determining iodine concentrations in terrestrial precipitation. The microphysical removal process was common to all elements indicating that the iodine and bromine are internally mixed within the snow crystals. We also show that organically bound iodine is the dominant iodine species in snow (61–75%), followed by iodide. Iodate was only found in two samples despite a detection limit of 0.3 nmol/l. Two unknown but most likely anionic organo-I species were also identified in IC-ICP-MS chromatograms and comprised 2–10% of the total iodine. The majority of the bromine was inorganic bromide with a max. of 32% organo-Br.

scholarly journals Biosynthetic potential assessment of four food pathogenic bacteria in hydrothermally silver nanoparticles fabrication

2019 ◽  
Vol 8 (1) ◽  
pp. 629-634 ◽  
Author(s):  
Amir Rahimirad ◽  
Afshin Javadi ◽  
Hamid Mirzaei ◽  
Navideh Anarjan ◽  
Hoda Jafarizadeh-Malmiri
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Zeta Potential ◽  
Pathogenic Bacteria ◽  
Heating Time ◽  
Synthesis Process ◽  
Ag Nps ◽  
Physico Chemical ◽  
Minimum Particle Size ◽  
Particle Size Analyzer

Abstract Silver nanoparticles (Ag NPs) were synthesized using four pathogenic bacterial extracts namely, Bacillus cereus, E. coli, Staphylococcus aureus and Salmonella entericasubsp.enterica. Synthesis process were hydrothermally accelerated using temperature, pressure and heating time of 121°C, 1.5 bar ad 15 min. Physico- chemical characteristics of the fabricated Ag NPs, including, particle size, polydispersity index (PDI), zeta potential, broad emission peak (λmax) and concentration were evaluated using UV-Vis spectrophotometer and dynamic light scattering (DLS) particle size analyzer. Furthermore, main existed functional groups in the provided bacterial extracts were recognized using Fourier transform infrared spectroscopy. The obtained results revealed that two main peaks were detected around 3453 and 1636.5 cm-1, for all bacterial extracts, were interrelated to the stretching vibrations of hydroxyl and amide groups which those had key roles in the reduction of ions and stabilizing of the formed Ag NPs. The results also indicated that, Ag NPs with much desirable characteristics, including minimum particle size (25.62 nm) and PDI (0.381), and maximum zeta potential (-29.5 mV) were synthesized using S. e. subsp. enterica extract. λmax, absorbance and concentration values for the fabricated Ag NPs with this bacterial extract were 400 nm, 0.202% a.u. and 5.87 ppm.

scholarly journals Green Synthesis, Characterization, Antioxidant, Antibacterial and Dye Degradation of Silver Nanoparticles using Combretum indicum Leaf Extract

2021 ◽  
Vol 34 (1) ◽  
pp. 216-222
Author(s):  
Arnannit Kuyyogsuy ◽  
Paweena Porrawatkul ◽  
Rungnapa Pimsen ◽  
Prawit Nuengmatcha ◽  
Benjawan Ninwong ◽  
...  
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Leaf Extract ◽  
Dye Degradation ◽  
Sunlight Irradiation ◽  
Particle Size Analyzer ◽  
Vis Spectroscopy ◽  
Edx Analyses ◽  
Aqueous Leaf Extract ◽  
And Staphylococcus Aureus

Silver nanoparticles were synthesized by bioreduction of silver nitrate using the aqueous leaf extract of Combretum indicum (CI-AgNPs). The synthesized CI-AgNPs exhibited a distinct absorption peak at 414 nm in UV-vis spectroscopy. Various parameters such as pH, temperature and time were optimized using spectrophotometry. The particle size of the CI-AgNPs was 48 nm as evaluated from the laser particle size analyzer. The XRD and EDX analyses confirmed the presence of silver in silver nanoparticles. Synthesized CI-AgNPs revealed significant antioxidant, antimicrobial (against Escherichia coli and Staphylococcus aureus) and photocatalytic (against methylene blue under sunlight irradiation) activities. Thus, an eco-friendly method was developed to synthesize silver nanoparticles using the C. indicum leaf extract.

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 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 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.

scholarly journals Challenges in Determining the Size Distribution of Nanoparticles in Consumer Products by Asymmetric Flow Field-Flow Fractionation Coupled to Inductively Coupled Plasma-Mass Spectrometry: The Example of Al2O3, TiO2, and SiO2 Nanoparticles in Toothpaste

Separations ◽  
2018 ◽  
Vol 5 (4) ◽  
pp. 56 ◽  
Author(s):  
Manuel Correia ◽  
Toni Uusimäki ◽  
Allan Philippe ◽  
Katrin Loeschner
Keyword(s):  
Mass Spectrometry ◽  
Particle Size ◽  
Flow Field ◽  
Inductively Coupled Plasma ◽  
Field Flow Fractionation ◽  
Asymmetric Flow ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Plasma Mass Spectrometry ◽  
Flow Fractionation

According to the current European regulation on cosmetics, any ingredient present as a nanomaterial should be indicated in the ingredient list. There is a need for analytical methods capable of determining the size of the relevant ingredients and thus assessing if these are nanomaterials or not. An analytical method based on asymmetric flow field-flow fractionation (AF4) and inductively coupled plasma-mass spectrometry (ICP-MS) was developed to determine the size of particles present in a commercial toothpaste. Multi-angle light scattering (MALS) was used for on-line size determination. The number-based particle size distributions (PSDs) of the particles were retrieved upon mathematical conversion of the mass-based PSDs recovered from the AF4-ICP-MS fractograms. AF4-ICP-MS allowed to separate and detect Al2O3 and TiO2 particles in the toothpaste and to retrieve a correct TiO2 number-based PSD. The potential presence of particles in the lower size range of the Al2O3 mass-based PSD had a strong impact on sizing and nanomaterial classification upon conversion. AF4 coupled with ICP-MS and MALS was found to be a powerful approach for characterization of different particles in a multiple-particle system such as toothpaste. Confirmation of particle size by a secondary method such as single particle ICP-MS or hydrodynamic chromatography was crucial.

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 DETECÇÃO E QUANTIFICAÇÃO DE NANOPARTÍCULAS DE PRATA POR SPICP-MS

Química Nova ◽  
2021 ◽  
Author(s):  
Fabio Bazilio ◽  
Cristiane Silva ◽  
Lísia Santos ◽  
Santos Vicentini ◽  
Silvana Jacob ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Silver Nanoparticles ◽  
Satisfactory Result ◽  
Inductively Coupled Plasma ◽  
Metallic Nanoparticles ◽  
Particle Concentration ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Plasma Mass Spectrometry ◽  
Detection And Quantification

DETECTION AND QUANTIFICATION OF SILVER NANOPARTICLES BY spICP-MS. The growing interest in nanotechnology has led to an increase in the production and application of nanoparticles worldwide. Due to the unique functional properties of nanoparticles, these materials are being used by many industries, including the agricultural and food sectors. Among the commercially available nanomaterials, it is possible to highlight those produced with silver nanoparticles. One of the most promising techniques for the analysis of metallic nanoparticles is the Inductively coupled plasma mass spectrometry (ICP-MS) performed in single particle mode (spICP-MS). However, the use of the technique in the detection and measurement of nanoparticles requires that the equipment be operated differently than when used to analyze dissolved metal solutions. Thus, this article presents the use of the spICP-MS technique for the measurement and quantification of nanoparticles, as well as their validation. The method proved to be adequate for the purpose, presenting a satisfactory result for the selectivity test and recovery of 83.7 (40 nm) and 77.6% (80 nm). The detection limits, determined for the most frequent size, dissolved silver concentration and particle concentration, were 17.5 nm, 0.736 ng mL-1,146 particles mL-1, respectively. Thus, the results obtained indicated the possibility of using the technique to determine the size and concentration of silver nanoparticles.

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