Plasma production of metallic nanoparticles

1992 ◽  
Vol 7 (8) ◽  
pp. 2107-2113 ◽  
Author(s):  
ChinHao Chou ◽  
Jonathan Phillips
Keyword(s):  
Iron Oxide ◽  
Metallic Iron ◽  
Metallic Nanoparticles ◽  
Composition Analysis ◽  
Iron Oxide Particles ◽  
Injection Point ◽  
Argon Plasmas ◽  
Transmission Electron ◽  
Microwave Power Source ◽  
Two Parameters

Metallic iron and iron oxide particles were produced by injecting ferrocene into the afterglow region of a low pressure, low power, plasma generated using a microwave power source. This was done as part of an effort to explore the feasibility of using flow type microwave plasmas for the production of metal nanoparticles. It was found that two parameters had the largest impact on the particles: injection point and plasma composition. Analysis done using Mössbauer effect spectroscopy, transmission electron microscopy, and x-ray diffraction indicated that low yields of small particles (ca. 10 nm) resulted from injection into the afterglow region. Much higher yields of large particles (ca. 50 nm) formed if the ferrocene was injected through the coupler. In hydrogen plasmas the particles that were produced were metallic iron, whereas in oxygen and argon plasmas the particles were iron oxide. In all cases significant amounts of graphitic carbon formed around the metal particles.

Microstructure, Stiffness and Corrosion of Bare and Phosphated Specimens Made by Sintering of Structured Iron-Iron Oxide Spheres

2020 ◽  
Vol 405 ◽  
pp. 411-416
Author(s):  
Miriam Kupková ◽  
Martin Kupka ◽  
Renáta Oriňáková ◽  
Radka Gorejová
Keyword(s):  
Iron Oxide ◽  
Iron Oxides ◽  
Metallic Iron ◽  
Galvanic Corrosion ◽  
Iron Phosphate ◽  
Reduction Reaction ◽  
Diffusion Control ◽  
Iron Oxide Particles ◽  
Flow Through ◽  
Iron Iron

Granulated iron oxide particles were incompletely reduced to structured particles comprised metallic iron and residual iron oxides. Structured particles were pressed into prismatic compacts and sintered. Some of sintered specimens were subsequently phosphatized and calcined. Specimens with an iron phosphate coating were found stiffer than specimens without coating. In Hanks' solution, a galvanic corrosion was induced by more noble iron oxides coupled to a less noble metallic iron. This could explain higher corrosion potentials and higher rates of iron dissolution in comparison with a pure iron. The coating of specimens with iron phosphates shifted corrosion potentials towards more negative values and slowed down the dissolution of iron. This was most likely caused by a reduction in oxygen flow through the coating to iron-oxide cathodes, which has enhanced the influence of diffusion control on the kinetics of reduction reaction.

Effects of Nanosized Iron Oxide with Different Morphology on Nanomechanical Properties of Nanocomposite Coating

2007 ◽  
Vol 336-338 ◽  
pp. 2218-2220 ◽  
Author(s):  
Qi Wang ◽  
Min Jang ◽  
Yun Fa Chen
Keyword(s):  
Iron Oxide ◽  
Ph Value ◽  
Nanocomposite Coating ◽  
Nanocomposite Coatings ◽  
Iron Oxide Particles ◽  
Nanomechanical Properties ◽  
Transmission Electron ◽  
Fecl3 Solution ◽  
Oxide Particles ◽  
Nanosized Iron

The nanocomposite coatings were prepared on the surface of PVC substrate using spinning technique with attempts of introducing nanosized iron oxide particles with different morphology into the organic-inorganic hybrid matrices. The hybrid matrices were derived from 3-glycidoxypropyltrimethoxysilane (GLYMO) and tetraethoxysilane (TEOS) with a process of hydrolyzing and condensation. Nanosized iron oxide particles were synthesized by hydrolysis of FeCl3 solution at different pH value and different temperature. The effects of different additions on nanomechanical properties of the nanocomposite coatings were investigated using X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and MTS Nano Indenter XP system. It was found that the acicular α-FeOOH and spherical α-Fe2O3 particles were synthesized, both of them dispersed homogeneously. Nanoindentation and nanoscratch behaviors of the nanoindenter system showed that both of the nanocomposite coatings reinforced the nanomechanical properties of the PVC obviously. Especially, the contribution of acicular α-FeOOH was more remarkable than the spherical α-Fe2O3.

scholarly journals EXPERIMENTAL STUDIES OF TOXIC EFFECTS’ OF METALLIC NANOPARTICLES AT IRON AND NONFERROUS INDUSTRIES AND RISK ASSESSMENT FOR WORKERS` HEALTH

2019 ◽  
Vol 96 (12) ◽  
pp. 1182-1187
Author(s):  
Marina P. Sutunkova
Keyword(s):  
Iron Oxide ◽  
Metallic Nanoparticles ◽  
Experimental Studies ◽  
Intratracheal Instillation ◽  
The Body ◽  
Chemical Additives ◽  
Iron Oxide Particles ◽  
Industrial Dust ◽  
White Rats

The paper summarizes main results of our toxicological “in vivo“ experiments on white rats exposed to either a) a single intratracheal instillation of silver, gold, iron oxide, copper oxide, nickel oxide, manganese oxide, zinc oxide and lead oxide nanoparticles (NPs) in stable water suspensions without any chemical additives, b) repeated intraperitoneal injections the same NPs, c) low-level long-term inhalation exposure to the iron oxide nano-aerosol. We found these NPs to be much more noxious on both cellular and systemic levels as compared with their one micrometer or even submicron counterparts. The retention and distribution of metal and metal oxide NPs in the body are controlled by both physiological and physicochemical processes, depended on both cytotoxicity and solubility in biological milieus (inherent in different NPs to varying degrees). The relative contributions of these processes to the toxicokinetics are various for different NPs, and specifically for iron oxide particles of an average diameter not exceeding 20 nm, which were studied in the chronic inhalation experiment, the role of the dissolution predominates. Our data were first to testify to the high activity of the macrophagic and neutrophillic pulmonary phagocytosis of NPs deposited in airways. This fact suggests safe levels of exposure to airborne nanoparticles to be possible in principle but should be much lower if compared with established ones for respective micrometric industrial dust.

Microscopic behavior and metallic iron morphology from reduction of iron oxide by CO/H2in a fluidized bed

2018 ◽  
Vol 51 (6) ◽  
pp. 1641-1651 ◽  
Author(s):  
Feng Lu ◽  
Liangying Wen ◽  
Hong Zhong ◽  
Jian Xu ◽  
Shengfu Zhang ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Fluidized Bed ◽  
Metallic Iron ◽  
Density Functional ◽  
Reduction Rate ◽  
Iron Ion ◽  
Ion Diffusion ◽  
Iron Oxide Particles ◽  
Reduction Of Iron ◽  
Oxide Particles

Fe2O3particles reduced by CO or H2exhibit different metallic iron morphology. To determine the mechanism of metallic iron formation during the reduction of iron oxide particles by CO/H2in a fluidized bed, an innovative multiscale method was used. This method was validated by experimental results. Density functional theory calculations demonstrate that the CO molecule has a strong stretching effect on the iron ion of wustite in the vertical direction, but the H2molecule has no directional force on the structure of wustite. The energy released from CO reduction is used to overcome the energy barrier of iron ion diffusion. However, H2addition will hinder iron ion diffusion by consuming energy. By analysis of the thermogravimetric curves of Fe2O3reduction, it was found that the adsorption ability of H2on the surface of FeO is weaker than that of CO. However, the reduction rate is higher under H2atmosphere, according to Langmuir adsorption isotherm theory. The morphology of metallic iron during the reduction of iron oxide particles by CO/H2was observed with a scanning electron microscope equipped with an energy dispersive X-ray spectroscopy detector

scholarly journals Economically viable synthesis of Fe3O4 nanoparticles and their characterization

2011 ◽  
Vol 13 (2) ◽  
pp. 1-5 ◽  
Author(s):  
V. Srivastava ◽  
P. Singh ◽  
C. Weng ◽  
Y. Sharma
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fourier Transform ◽  
Iron Oxide ◽  
Ammonia Solution ◽  
Bet Surface Area ◽  
Iron Oxide Particles ◽  
X Ray ◽  
Transmission Electron ◽  
Oxide Particles

Economically viable synthesis of Fe3O4 nanoparticles and their characterization Nano iron oxide particles (Fe3O4) were synthesized by coprecipitation of Fe2+ and Fe3+ by ammonia solution in the aqueous phase. Various instrumentation methods such as X ray Diffractometry (XRD), Transmission Electron Microscopy (TEM), Fourier Transform Infrared (FTIR) spectroscopy, Brunauer-Emmett-Teller (BET) and Vibrating Sample Magnetometery (VSM) were used to characterize the properties of nanoparticles. The size of the nanoparticles was measured and was found to be between 10 to 15 nm. The value of saturation magnetization of the nanoparticles was found to be 55.26 emu/g. The BET surface area of nano iron oxide particles measured to be 86.55 m2/g.

TEM observation of iron oxide pillars in montmorillonite

1990 ◽  
Vol 48 (4) ◽  
pp. 882-883
Author(s):  
H. Mori ◽  
Y. Murata ◽  
H. Yoneyama ◽  
H. Fujita
Keyword(s):  
Aqueous Solution ◽  
Iron Oxide ◽  
Fine Particles ◽  
Aqueous Suspension ◽  
Volume Ratio ◽  
Exchange Capacity ◽  
Nano Composites ◽  
Pillared Montmorillonite ◽  
Topographic Features ◽  
Transmission Electron

Recently, a new sort of nano-composites has been prepared by incorporating such fine particles as metal oxide microcrystallites and organic polymers into the interlayer space of montmorillonite. Owing to their extremely large specific surface area, the nano-composites are finding wide application[1∼3]. However, the topographic features of the microstructures have not been elucidated as yet In the present work, the microstructures of iron oxide-pillared montmorillonite have been investigated by high-resolution transmission electron microscopy.Iron oxide-pillared montmorillonite was prepared through the procedure essentially the same as that reported by Yamanaka et al. Firstly, 0.125 M aqueous solution of trinuclear acetato-hydroxo iron(III) nitrate, [Fe3(OCOCH3)7 OH.2H2O]NO3, was prepared and then the solution was mixed with an aqueous suspension of 1 wt% clay by continuously stirring at 308 K. The final volume ratio of the latter aqueous solution to the former was 0.4. The clay used was sodium montmorillonite (Kunimine Industrial Co.), having a cation exchange capacity of 100 mequiv/100g. The montmorillonite in the mixed suspension was then centrifuged, followed by washing with deionized water. The washed samples were spread on glass plates, air dried, and then annealed at 673 K for 72 ks in air. The resultant film products were approximately 20 μm in thickness and brown in color.

scholarly journals Dietary Nanoparticles Interact with Gluten Peptides and Alter the Intestinal Homeostasis Increasing the Risk of Celiac Disease

2021 ◽  
Vol 22 (11) ◽  
pp. 6102
Author(s):  
Clara Mancuso ◽  
Francesca Re ◽  
Ilaria Rivolta ◽  
Luca Elli ◽  
Elisa Gnodi ◽  
...  
Keyword(s):  
Celiac Disease ◽  
Metallic Nanoparticles ◽  
Synergistic Effects ◽  
Food Sector ◽  
Intestinal Homeostasis ◽  
Gluten Peptides ◽  
Transmission Electron ◽  
Duodenal Biopsies ◽  
Junction Proteins

The introduction of metallic nanoparticles (mNPs) into the diet is a matter of concern for human health. In particular, their effect on the gastrointestinal tract may potentially lead to the increased passage of gluten peptides and the activation of the immune response. In consequence, dietary mNPs could play a role in the increasing worldwide celiac disease (CeD) incidence. We evaluated the potential synergistic effects that peptic-tryptic-digested gliadin (PT) and the most-used food mNPs may induce on the intestinal mucosa. PT interaction with mNPs and their consequent aggregation was detected by transmission electron microscopy (TEM) analyses and UV–Vis spectra. In vitro experiments on Caco-2 cells proved the synergistic cytotoxic effect of PT and mNPs, as well as alterations in the monolayer integrity and tight junction proteins. Exposure of duodenal biopsies to gliadin plus mNPs triggered cytokine production, but only in CeD biopsies. These results suggest that mNPs used in the food sector may alter intestinal homeostasis, thus representing an additional environmental risk factor for the development of CeD.

scholarly journals Aqueous one-pot synthesis of well-defined zwitterionic diblock copolymers by RAFT polymerization: an efficient and environmentally-friendly route to a useful dispersant for aqueous pigments

2021 ◽  
Vol 23 (3) ◽  
pp. 1248-1258
Author(s):  
Shannon M. North ◽  
Steven P. Armes
Keyword(s):  
Iron Oxide ◽  
Diblock Copolymers ◽  
Raft Polymerization ◽  
Environmentally Friendly ◽  
Iron Oxide Particles ◽  
One Pot ◽  
One Pot Synthesis ◽  
Highly Effective ◽  
Oxide Particles

An atom-efficient, wholly aqueous one-pot synthesis of zwitterionic diblock copolymers has been devised. Such copolymers can serve as highly effective aqueous dispersants for nano-sized transparent yellow iron oxide particles.

scholarly journals The Antimicrobial and Anti-Inflammatory Effects of Silver Nanoparticles Synthesised from Cotyledon orbiculata Aqueous Extract

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1343
Author(s):  
Caroline Tyavambiza ◽  
Abdulrahman Mohammed Elbagory ◽  
Abram Madimabe Madiehe ◽  
Mervin Meyer ◽  
Samantha Meyer
Keyword(s):  
Staphylococcus Aureus ◽  
Silver Nanoparticles ◽  
Metallic Nanoparticles ◽  
Methicillin Resistance ◽  
Antimicrobial Activities ◽  
Transmission Electron ◽  
Anti Inflammatory ◽  
Anti Inflammation ◽  
Important Medicinal Plant ◽  
Pro Inflammatory Cytokines

Cotyledon orbiculata, commonly known as pig’s ear, is an important medicinal plant of South Africa. It is used in traditional medicine to treat many ailments, including skin eruptions, abscesses, inflammation, boils and acne. Many plants have been used to synthesize metallic nanoparticles, particularly silver nanoparticles (AgNPs). However, the synthesis of AgNPs from C. orbiculata has never been reported before. The aim of this study was to synthesize AgNPs using C. orbiculata and evaluate their antimicrobial and immunomodulatory properties. AgNPs were synthesized and characterized using Ultraviolet-Visible Spectroscopy (UV-Vis), Dynamic Light Scattering (DLS) and High-Resolution Transmission Electron Microscopy (HR-TEM). The antimicrobial activities of the nanoparticles against skin pathogens (Staphylococcus aureus, Staphylococcus epidermidis, Methicillin Resistance Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans) as well as their effects on cytokine production in macrophages (differentiated from THP-1 cells) were evaluated. The AgNPs from C. orbiculata exhibited antimicrobial activity, with the highest activity observed against P. aeruginosa (5 µg/mL). The AgNPs also showed anti-inflammatory activity by inhibiting the secretion of pro-inflammatory cytokines (TNF-alpha, IL-6 and IL-1 beta) in lipopolysaccharide-treated macrophages. This concludes that the AgNPs produced from C. orbiculata possess antimicrobial and anti-inflammation properties.

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