Articles de revues : « Micro-sized particles of iron oxide »

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Muska, M., A. Naeem, M. Hamayun, S. L. Badshah, M. Farooq, M. Fida, A. Mahmood, K. H. Shah et Y. N. Mabkhot. « Comparative sorption studies of chromate by nano-and-micro sized Fe2O3 particles ». Open Chemistry 15, n^o 1 (14 juin 2017) : 147–55. http://dx.doi.org/10.1515/chem-2017-0016.

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AbstractThe comparative adsorption studies of Cr (VI) on nano and micro-powder Fe2O3 were investigated using kinetics and batch adsorption techniques. The uptake of chromate onto both the oxides of iron was observed to be dependent on the pH, contact time, temperature, media dosage and concentration of chromate anions. The values of sorption maxima were higher in the case of Fe2O3 nanopowder than the micro-powder which can be ascribed to the high surface area and point of zero charge (PZC) of the former oxide. The Dubinin-Radushkivech and Langmuir models were found well fitted for the description of the batch adsorption data. The FTIR studies confirmed that the hexavalent chromium was adsorbed onto both the iron oxides in the form of the Cr2O72−.

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Kong, Yuan Yuan, et Hao Zhou. « Formation and Magnetic Characterization of Magnesium Oxide / Iron Nano Composite Particles ». Advanced Materials Research 236-238 (mai 2011) : 1927–30. http://dx.doi.org/10.4028/www.scientific.net/amr.236-238.1927.

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Nano-sized composite magnetic particles MgO /Fe were in-situ combustion synthesized at 620°Cfor the Mg-70.9wt%Fe3O4 system. In this paper, we discussed the reactant ratio on the influence of micro-morphology and the magnetic properties of nanoparticles. It was indentified that: Mg(29.1wt%) was the suitable reactant ratio, the sintered composite spherical particles with mean diameter 40nm distributed evenly, particles had good soft magnetic properties, and it was the future drug carriers materials.

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Khushnood, Rao Arsalan, Siraj ud din, Nafeesa Shaheen, Sajjad Ahmad et Filza Zarrar. « Bio-inspired self-healing cementitious mortar using Bacillus subtilis immobilized on nano-/micro-additives ». Journal of Intelligent Material Systems and Structures 30, n^o 1 (3 novembre 2018) : 3–15. http://dx.doi.org/10.1177/1045389x18806401.

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Bio-inspired self-healing strategies are much innovative and potentially viable for the production of healable cement mortar matrix. The present research explores the feasibility of gram-positive “Bacillus subtilis” microorganisms in the effective healing of nano-/micro-scale-induced structural and non-structural cracks. The main concern related to the survival of such microorganisms in cementitious environment has been successfully addressed by devising proficient immobilization scheme coherently. The investigated immobilizing media includes iron oxide nano-sized particles, micro-sized limestone particles, and milli-sized siliceous sand. The effect of induced B. subtilis microorganisms immobilized on nano-micro-additives was analyzed by the quantification of average compressive resistance of specimens (ASTM C109) and healing evaluation. The healing process was mechanically gauged by compressive strength regain of pre-cracked specimens after the healing period of 28 days. The pre-cracking load was affixed at 80% of ultimate compressive stress “[Formula: see text]” while the age of pre-cracking was kept variable as 3, 7, 14, and 28 days to precisely correlate healing effectiveness as the function of cracking period. The healing mechanism was further explored by examining the healed micro-crack using field emission scanning electron micrographs, energy dispersive x-ray spectrographs, and thermogravimetry. The results revealed that B. subtilis microorganisms contribute extremely well in the improvement of compressive strength and efficient healing process of pre-cracked cement mortar formulations. The iron oxide nano-sized particles were found to be the most effective immobilizer for preserving B. subtilis microbes till the generation of cracks followed by siliceous sand and limestone particles. The micro-graphical and chemical investigations endorsed the mechanical measurements by evidencing calcite precipitation in the induced nano-/micro-cracks as a result of microbial activity.

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Cuong, Le Viet, Pham Duc Thang et Nguyen The Hien. « A Simple Process to Fabricate Micro Flux Sources with High Magnetic Field Gradient ». Communications in Physics 24, n^o 3S1 (7 novembre 2014) : 85–89. http://dx.doi.org/10.15625/0868-3166/24/3s1/5225.

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In this paper, we present a fabrication process to produce the micro-sized magnetic structures based on the hard magnetic powders. Under the magnetic field originated from a micro patterned hard magnetic film, these magnetic powders are magnetically aligned to form arrays of the micro magnets on a polydimethysiloxane (PDMS) substrate. The high magnetic field gradient and stable magnetic flux can be obtained at certain micro-sized area on the surface of the micro magnets. The fabricated structures have been used for trapping iron oxide particles. Generally this fabrication process is simple, low cost and the micro magnets can be used for further applications in biology, medicine and beyond.

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Yogo, Toshinobu, Tomoyuki Nakamura, Wataru Sakamoto et Shin-ichi Hirano. « Synthesis of magnetic particle/organic hybrid from metalorganic compounds ». Journal of Materials Research 14, n^o 7 (juillet 1999) : 2855–60. http://dx.doi.org/10.1557/jmr.1999.0381.

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A nanocrystalline magnetic particle/oligomer hybrid was successfully synthesized by polymerization of iron(III) 3-allylacetylacetonate (IAA) followed by in situ hydrolysis. An iron oxide particle/oligomer hybrid was synthesized by hydrolysis of the IAA oligomer under alkaline and reducing conditions by the addition of hydrazine or methylhydrazine. Crystalline particles of approximately 10 nm were found to be dispersed in the oligomeric matrix. The nanocrystalline particles were identified to be iron oxide spinel by x-ray diffraction analysis and electron diffraction. The nanometer-sized ferrimagnetic iron oxide particle/oligomer hybrid showed a typical superparamagnetic behavior.

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Siddhartha, O. Sai, et S. V. Satyanarayana. « Iron Oxides' Influence on the Thermal Decomposition of Pure Ammonium Perchlorate : A Comprehensive Review ». Scholars International Journal of Chemistry and Material Sciences 7, n^o 04 (9 avril 2024) : 35–44. http://dx.doi.org/10.36348/sijcms.2024.v07i04.001.

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The combustion of ammonium perchlorate (AP) has long been a focal point in the development of solid rocket propellants, with particular attention paid to the catalytic effects of iron oxides. Beginning in the 1950s, researchers have diligently studied the kinetics and mechanisms underlying AP combustion, with a focus on both micron-sized and nano-sized iron oxide catalysts due to their widespread application in rocket formulations worldwide. This research effort specifically excludes investigations involving alternative iron oxide-based catalysts, such as doped or mixed oxides, or supported iron oxides, as they are not commonly utilized in major rocket propellant formulations. Despite variations in specific parameters like activation energy and heat of dissociation, the fundamental understanding of AP decomposition with iron oxides remains consistent with earlier findings. Notably, micron-sized catalysts have minimal impact on the low-temperature decomposition (LTD) of AP but can influence high-temperature decomposition (HTD) by altering decomposition temperatures and reducing activation energy. In contrast, nano-sized catalysts tend to accelerate the reaction to such an extent that the LTD phase is often bypassed altogether due to the rapid consumption of NH3, a crucial component in the process. However, the transition to nano-sized particles presents a new challenge: the propensity for particle agglomeration. Current research endeavours are therefore dedicated to devising effective strategies to mitigate this issue and harness the full potential of nano-sized iron oxide catalysts in rocket propellant formulations.

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Chandrasekharan, Prashant, Renesmee Kuo, K. L. Barry Fung, Chinmoy Saayujya, Jacob Bryan, Mariam Yousuf, Benjamin Fellows et al. « Magnetic Particle Imaging in Vascular Imaging, Immunotherapy, Cell Tracking, and Noninvasive Diagnosis ». Molecular Imaging 2023 (15 mars 2023) : 1–22. http://dx.doi.org/10.1155/2023/4131117.

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Magnetic particle imaging (MPI) is a new tracer-based imaging modality that is useful in diagnosing various pathophysiology related to the vascular system and for sensitive tracking of cytotherapies. MPI uses nonradioactive and easily assimilated nanometer-sized iron oxide particles as tracers. MPI images the nonlinear Langevin behavior of the iron oxide particles and has allowed for the sensitive detection of iron oxide-labeled therapeutic cells in the body. This review will provide an overview of MPI technology, the tracer, and its use in vascular imaging and cytotherapies using molecular targets.

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Huang, Yuan Ming, Bao Gai Zhai, Qing Lan Ma et Ming Meng. « Magnetic Properties of Ferrous Ferric Oxide Confined in Porous Silicon ». Materials Science Forum 663-665 (novembre 2010) : 1142–45. http://dx.doi.org/10.4028/www.scientific.net/msf.663-665.1142.

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During the chemical synthesis nanometer-sized particles of ferrous iron oxide were in situ infiltrated into the mesopores in a porous silicon film. The microstructures of porous silicon and the magnetic properties of the nanometer-sized particles of the ferrous iron oxide were characterized with scanning electron microscopy, X-ray diffractometry, and the hysteresis loop measurement, respectively. Our results have demonstrated that the magnetic properties of the nanometer-sized Fe3O4 particles can be dramatically modified when they are confined into the mesopores of the porous silicon film.

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Leybo, Denis, Marat Tagirov, Elizaveta Permyakova, Anton Konopatsky, Konstantin Firestein, Feruza Tuyakova, Dmitry Arkhipov et Denis Kuznetsov. « Ascorbic Acid-Assisted Polyol Synthesis of Iron and Fe/GO, Fe/h-BN Composites for Pb2+ Removal from Wastewaters ». Nanomaterials 10, n^o 1 (22 décembre 2019) : 37. http://dx.doi.org/10.3390/nano10010037.

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Iron powders and Fe/graphene oxide and Fe/boron nitride composites were synthesized by means of a polyol synthesis method. The effect of NaOH/Fe and ascorbic acid/Fe ratios on the characteristics of synthesized products were evaluated. The samples were characterized by X-ray diffraction, scanning and transmission electron microscopy, low-temperature nitrogen adsorption and Raman-spectroscopy. Ascorbic acid-assisted polyol synthesis resulted in the 10-fold decrease of the iron particles’ size and almost 2-fold increase of lead removal efficiency. The deposition of iron on the surface of graphene oxide lead to the formation of small 20–30 nm sized particles as well as bigger 200–300 nm sized particles, while the reduction in presence of boron nitride resulted in the 100–200 nm sized particles. The difference is attributed to the surface state of graphene oxide and boron nitride. Adsorption properties of the obtained materials were studied in the process of Pb2+ ion removal from wastewater.

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Mehdikhani, Behzad, et Gholam Borhani. « Optical spectroscopy of sodium silicate glasses prepared with nano- and micro-sized iron oxide particles ». Processing and Application of Ceramics 7, n^o 3 (2013) : 117–21. http://dx.doi.org/10.2298/pac1303117m.

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Zakharova, Elena V., Ella L. Dzidziguri, Elena N. Sidorova, Andrey A. Vasiliev, Ivan A. Pelevin, Dmitriy Yu Ozherelkov, Anton Yu Nalivaiko et Alexander A. Gromov. « Characterization of Multiphase Oxide Layer Formation on Micro and Nanoscale Iron Particles ». Metals 11, n^o 1 (23 décembre 2020) : 12. http://dx.doi.org/10.3390/met11010012.

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The article presents a detailed study and characterization of the oxide layers on the surface of iron particles of various sizes. Ten iron samples with a size range from a few nm to 50 µm were studied in detail using SEM, TEM, XRD, and TGA analysis. The composition of the multiphase oxide layers on the powder surface was investigated. The main components of the oxide layer were FeO, Fe3O4, and Fe2O3. By the obtained data, a model for the calculation of a multiphase oxide layer thickness on the surface of iron particles was proposed. The proposed model was validated and can be used for the characterization and certification of micro– and nanoscale iron particles.

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Apblett, Allen W., Satish I. Kuriyavar et B. P. Kiran. « Preparation of micron-sized spherical porous iron oxide particles ». Journal of Materials Chemistry 13, n^o 5 (27 mars 2003) : 983–85. http://dx.doi.org/10.1039/b301259j.

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Yogo, Toshinobu, Tomoyuki Nakamura, Wataru Sakamoto et Shin-ichi Hirano. « Synthesis of transparent magnetic particle/organic hybrid film using iron–organics ». Journal of Materials Research 15, n^o 10 (octobre 2000) : 2114–20. http://dx.doi.org/10.1557/jmr.2000.0304.

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A transparent magnetic particle/organic film was synthesized from an iron–organic compound. Iron(III) 3-allylacetylacetonate (IAA) was polymerized followed by in situ hydrolysis yielding an iron oxide particle/oligomer hybrid. The sizes of magnetic particles were dependent upon the hydrolysis conditions of the IAA oligomers. A nanometer-sized ferrimagnetic iron oxide particle/oligomer hybrid showed a magnetization curve with no coercive force at 300 K and that with Hc of 200 Oe at 4.2 K, respectively. The magnetization versus H/T curves at 300 and 77 K were superimposed on each other and satisfied the Langevin equation. The transparent hybrid film showed a magnetization curve at room temperature. The absorption spectrum of the film was shifted to higher energy by 0.14 eV compared with that of bulk magnetite. The absorption edge of the film was blue-shifted.

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Jeong, Gi Young, Mi Yeon Park, Konrad Kandler, Timo Nousiainen et Osku Kemppinen. « Mineralogical properties and internal structures of individual fine particles of Saharan dust ». Atmospheric Chemistry and Physics 16, n^o 19 (4 octobre 2016) : 12397–410. http://dx.doi.org/10.5194/acp-16-12397-2016.

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Abstract. Mineral dust interacts with incoming/outgoing radiation, gases, other aerosols, and clouds. The assessment of its optical and chemical impacts requires knowledge of the physical and chemical properties of bulk dust and single particles. Despite the existence of a large body of data from field measurements and laboratory analyses, the internal properties of single dust particles have not been defined precisely. Here, we report on the mineralogical organization and internal structures of individual fine ( < 5 µm) Saharan dust particles sampled at Tenerife, Canary Islands. The bulk of Tenerife dust was composed of clay minerals (81 %), followed by quartz (10 %), plagioclase (3 %), and K-feldspar (2 %). Cross-sectional slices of Saharan dust particles prepared by the focused ion beam technique were analyzed by transmission electron microscopy (TEM) to probe the particle interiors. TEM analysis showed that the most common particle type was clay-rich agglomerate, dominated by illite–smectite series clay minerals with subordinate kaolinite. Submicron grains of iron (hydr)oxides (goethite and hematite) were commonly dispersed through the clay-rich particles. The median total volume of the iron (hydr)oxide grains included in the dust particles was estimated to be about 1.5 % vol. The average iron content of clay minerals, assuming 14 wt % H2O, was determined to be 5.0 wt %. Coarse mineral cores, several micrometers in size, were coated with thin layers of clay-rich agglomerate. Overall, the dust particles were roughly ellipsoidal, with an average axial ratio of 1.4 : 1.0 : 0.5. The mineralogical and structural properties of single Saharan dust particles provide a basis for the modeling of dust radiative properties. Major iron-bearing minerals, such as illite–smectite series clay minerals and iron (hydr)oxides, were commonly submicron- to nano-sized, possibly enhancing their biogeochemical availability to remote marine ecosystems lacking micronutrients.

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North, Shannon M., et Steven P. Armes. « 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 ». Green Chemistry 23, n^o 3 (2021) : 1248–58. http://dx.doi.org/10.1039/d0gc04271d.

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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.

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Neuwelt, Edward A., Ralph Weissleder, Gajanan Nilaver, Robert A. Kroll, Simon Roman-Goldstein, Jerzy Szumowski, Michael A. Pagel et al. « Delivery of Virus-sized Iron Oxide Particles to Rodent CNS Neurons ». Neurosurgery 34, n^o 4 (avril 1994) : 777–84. http://dx.doi.org/10.1227/00006123-199404000-00048.

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Neuwelt, Edward A., Ralph Weissleder, Gajanan Nilaver, Robert A. Kroll, Simon Roman-Goldstein, Jerzy Szumowski, Michael A. Pagel et al. « Delivery of Virus-sized Iron Oxide Particles to Rodent CNS Neurons ». Neurosurgery 34, n^o 4 (1 avril 1994) : 777–84. http://dx.doi.org/10.1097/00006123-199404000-00048.

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Shapiro, Erik M., Stanko Skrtic et Alan P. Koretsky. « Sizing it up : Cellular MRI using micron-sized iron oxide particles ». Magnetic Resonance in Medicine 53, n^o 2 (2005) : 329–38. http://dx.doi.org/10.1002/mrm.20342.

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Williams, John B., Qing Ye, T. Kevin Hitchens, Christina L. Kaufman et Chien Ho. « MRI detection of macrophages labeled using micrometer-sized iron oxide particles ». Journal of Magnetic Resonance Imaging 25, n^o 6 (2007) : 1210–18. http://dx.doi.org/10.1002/jmri.20930.

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Elias, Andrew, et Andrew Tsourkas. « Imaging circulating cells and lymphoid tissues with iron oxide nanoparticles ». Hematology 2009, n^o 1 (1 janvier 2009) : 720–26. http://dx.doi.org/10.1182/asheducation-2009.1.720.

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Abstract The use of nanometer-sized iron oxide nanoparticles and micron-sized iron oxide particles as magnetic resonance (MR) contrast agents has garnered a high degree of interest in diverse areas of biology and medicine. Applications such as cell tracking, molecular imaging, gene detection, and lymphography are being explored to provide insight into disease mechanisms, monitor therapeutic efficacy, and facilitate diagnostic imaging. What makes iron oxide so appealing is a number of favorable properties including high detectability by MR, biodegradability and low toxicity. Here we describe the recent progress on the use of magnetic nanoparticles in imaging circulating cells and lymphoid tissues. The study of the lymph system and the biodistribution of various circulating immune cells is important in the diagnosis, prognosis, and treatment of a wide range of diseases and is expected to have a profound effect on patient outcome.

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Neto, Michel E., David W. Britt, Kyle A. Jackson, João H. V. Almeida Junior, Rodrigo S. Lima, Dimas A. M. Zaia, Tadeu T. Inoue et Marcelo A. Batista. « Synthesis and Characterization of Zinc, Iron, Copper, and Manganese Oxides Nanoparticles for Possible Application as Plant Fertilizers ». Journal of Nanomaterials 2023 (23 février 2023) : 1–8. http://dx.doi.org/10.1155/2023/1312288.

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This research evaluates the synthesis and characterization of nanometric-sized metallic particles with potential application as support materials for supplying nutrients to plants. Nanoscale Zn, Mn, Fe, and Cu oxides particles were synthesized using microwave-assisted synthesis. Nanoparticles (NPs) were characterized with Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), specific surface area (SSA), and total chemical analysis. Synthesized NPs were all in oxide forms and characterized for confirmation of size, shape, surface structure, crystalline nature, and study of elemental proportion. The results indicate that synthesized NPs size was ranged between 20 and 50 nm and was all in their respective oxide forms as ZnO, Mn3O4, Fe3O4, and CuO.

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Hao, Yalin, et Amyn S. Teja. « Continuous hydrothermal crystallization of α–Fe2O3 and Co3O4 nanoparticles ». Journal of Materials Research 18, n^o 2 (février 2003) : 415–22. http://dx.doi.org/10.1557/jmr.2003.0053.

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Iron oxide (α–Fe2O3) and cobalt oxide (Co3O4) were produced via precipitation reactions carried out in a continuous hydrothermal apparatus. The resulting particles were nanometer-sized because of the high supersaturations generated when metal nitrate solutions are combined with sodium hydroxide or with hot, compressed water. The average particle size increased with the metal nitrate feed concentration and with residence time. A logarithmic relationship was obtained between the particle size and feed concentration and between particle size and residence time in the apparatus. The production of nanoparticles with narrow size distribution was shown to require low metal nitrate feed concentrations and short residence times. In the range of temperatures studied in this work, temperature apparently had no effect on the size except when cobalt nitrate was contacted with supercritical water in the absence of sodium hydroxide. In this case, large cobalt oxide particles were obtained when the temperature was above the critical temperature of water.

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Yee, Maxine, et Iskandar I. Yaacob. « Synthesis and Characterization of Iron Oxide Nanostructured Particles in Na–Y Zeolite Matrix ». Journal of Materials Research 19, n^o 3 (mars 2004) : 930–36. http://dx.doi.org/10.1557/jmr.2004.19.3.930.

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Formation of iron oxide nanoparticles within the internal cages of Na–Y zeolites was investigated. Sodium ions within the zeolites were replaced with iron(II) ions. Elemental composition studies showed a significant amount of iron in the exchanged sample. NaOH and dropwise additions of H2O2 at 60 °C triggered formation of zeolite–iron oxide systems. X-ray diffraction (XRD) patterns showed diminishing zeolite peaks along with evolution of peaks corresponding to γ-Fe2O3 and α-Fe2O3 with increasing NaOH concentration. Morphological changes from hexagonal-shaped zeolite to clusters of fine particles were observed under scanning electron microscope. Particles with about 15-nm diameter were detected by transmission electron microscopy. γ-Fe2O3 crystallites of 13.4 nm were determined from the broadening of XRD peaks. The magnetization curves of samples (precipitated using NaOH with concentrations of 2.0 M and above) showed absence of hysteresis and passed through the origin, indicating the particles are superparamagnetic. Gas adsorption–desorption measurement of the system precipitated with 2.0 M NaOH revealed a 26% increase in its specific surface area, indicating the presence of nanometer-sized particles within the zeolites.

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Kadoshnikov, Vadim M., Tetyana I. Melnychenko, Oksana M. Arkhipenko, Danylo H. Tutskyi, Volodymyr O. Komarov, Leonid A. Bulavin et Yuriy L. Zabulonov. « A Composite Magnetosensitive Sorbent Based on the Expanded Graphite for the Clean-Up of Oil Spills : Synthesis and Structural Properties ». C 9, n^o 2 (12 avril 2023) : 39. http://dx.doi.org/10.3390/c9020039.

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Oil spills necessitate the development of effective methods for preventing their damaging effects on the environment. A number of physical, chemical, thermal, and biological methods are used to combat oil spills. Among them, sorption is considered to be efficient in removing thin oil films from water surfaces. Currently, there is an urgent need for simple methods of obtaining oil sorbents that include a magnetosensitive component to optimize the process of removing oil from the water surface. The purpose of the work is to obtain and research oil sorbents resistant to destruction, with increased bulk density and complex magnetosensitivity, based on thermally expanded graphite (TEG) with the inclusion of micro- and nano-particles of iron and its oxides. The structure and composition of the new composite material was characterized using scanning electron microscopy, energy dispersive X-ray analysis, X-ray diffractometry, thermogravimetric analysis, and laser diffraction particle sizing. The composite sorbent comprised TEG with the inclusion of iron-containing magnetosensitive particles. Metal-carbon nanoparticles (MCN) were used as the magnetosensitive component; they had a magnetosensitive iron core covered with a carbon shell. We used two methods of synthesis, namely (i) mechanical mixing of the TEG flakes and MCN particles, and (ii) applying a thermal shock (microwave processing) to the mixture of graphite intercalated with sulphuric acid and micro- and nanoparticles of iron and iron oxides. In the first case, MCN particles were fixed on the faces, edges, and other surface defects of the TEG flakes due to intermolecular forces, coordinate bonds, and electrostatic interaction. The strong adhesion of magnetosensitive iron/iron oxide and TEG particles in the second case was due to the mutual dissolution of iron and carbon components during the thermal shock, which formed an interfacial layer in which iron carbide is present. The presence of magnetosensitive components in the structure of the proposed oil sorbents allows the use of magnetic separation for the localization and removal of oil spills, increases the density of sorbents, and, accordingly, leads to a decrease in windage while retaining the advantageous properties of thermally expanded graphite. According to the results of laboratory studies, the efficiency of removing oil from the water surface is not lower than 95–96%.

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DAKSHNAMOORTHY, Easu, Siddharthan ARJUNAN, Amruthan RADHAKRISHNAN et Andal GOPAL. « Study on the Influence of Synthesized Nano Ferrite Powder and Micron Ferrite Powder on Damping of a Single Degree of Freedom System ». Mechanics 29, n^o 4 (9 août 2023) : 334–39. http://dx.doi.org/10.5755/j02.mech.32055.

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Magneto Rheological Fluid (MRF) damper has been opted as a promising semi active element of advanced suspension system. This work focuses on the damping nature of magnetorheological fluid under the influence of a magnetic field strength, size and shape of the of the iron oxide particles. A reduced scale single degree of freedom quarter car model with two stage magnetorheological damper, viscosity measurement setup, synthesized and commercially available Fe2O3 powders are used for the experimental study. An air cooled electro-dynamic shaker, Data acquisition system, accelerometers and the Lab view software acquires and analyzes the response of the quarter car model. X-ray Diffraction and Scanning electron microscopy characterize the morphology of iron oxide particles. The vertical acceleration, the displacement, the transmissibility ratio and the damping characteristics are analyzed based on the response of the top plate at different frequencies of base excitation. The results show that the magnetorheological fluid made with nano iron oxide powder has better damping characteristics than that of micron sized iron oxide powder

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Nikkanen, Juha-Pekka, Helmi Keskinen, Mikko Aromaa, Mikael Järn, Tomi Kanerva, Erkki Levänen, Jyrki M. Mäkelä et Tapio Mäntylä. « Iron Oxide Doped Alumina-Zirconia Nanoparticle Synthesis by Liquid Flame Spray from Metal Organic Precursors ». Research Letters in Nanotechnology 2008 (2008) : 1–4. http://dx.doi.org/10.1155/2008/516478.

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The liquid flame spray (LFS) method was used to make iron oxide doped alumina-zirconia nanoparticles. Nanoparticles were generated using a turbulent, high-temperature (Tmax⁡∼3000 K)H2-O2flame. The precursors were aluminium-isopropoxide, zirconium-n-propoxide, and ferrocene in xylene solution. The solution was atomized into micron-sized droplets by high velocityH2flow and introduced into the flame where nanoparticles were formed. The particle morphology, size, phase, and chemical composition were determined by TEM, XRD, XPS, andN2-adsorption measurements. The collected particulate material consists of micron-sized aggregates with nanosized primary particles. In both doped and undoped samples, tetragonal phase of zirconia was detected in room temperature while alumina was found to be noncrystalline. In the doped powder, Fe was oxidized toFe2O3. The primary particle size of collected sample was approximately from 6 nm to 40 nm. Doping was observed to increase the specific surface area of the powder from 39 m2/g to 47 m2/g.

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Nakamura, Satoshi, Wataru Sakamoto et Toshinobu Yogo. « In situ Synthesis of Nickel Ferrite Nanoparticle/organic Hybrid ». Journal of Materials Research 20, n^o 6 (1 juin 2005) : 1590–96. http://dx.doi.org/10.1557/jmr.2005.0210.

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A NiFe2O4 particle/organic hybrid was synthesized in situ from iron-organic and nickel organic compounds below 100 °C. A mixture of nickel (II) acetylacetonate (NA) and iron (III) 3-allylacetylacetonate (IAA) was hydrolyzed and polymerized yielding spinel oxide particle/oligomer hybrid. X-ray diffraction analysis revealed that the crystallinity of spinel particles was dependent upon the hydrolysis conditions of NA-IAA. Nanocrystalline nickel ferrite particles around 10 nm were uniformly dispersed in the organic matrix. The formation of nickel ferrite was confirmed by energy-dispersive x-ray and x-ray photoelectron spectroscopy. The saturation magnetization of hybrid increased with increasing water amount for hydrolysis. Nano-sized nickel ferrite particle/organic hybrid showed a BH curve with no remanence above 75 K. The magnetization versus H/T curves at 300, 200, and 75 K were superimposed on the same curve and satisfied the Langevin equation. The remanent magnetization and coercive field of the hybrid were 7.4 emu/g and 460 Oe, respectively, at 5 K.

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Rafieepour, Athena, Mansour R. Azari, Habibollah Peirovi, Fariba Khodagholi, Jalal Pourahmad Jaktaji, Yadollah Mehrabi, Parvaneh Naserzadeh et Yousef Mohammadian. « Investigation of the effect of magnetite iron oxide particles size on cytotoxicity in A549 cell line ». Toxicology and Industrial Health 35, n^o 11-12 (novembre 2019) : 703–13. http://dx.doi.org/10.1177/0748233719888077.

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Introduction: Magnetite as iron oxide is widely used in various industries, in the pharmaceutical industry in particular where it is used for its magnetic properties. The environmental and occupational exposure to airborne nanoparticles and microparticles of iron oxide compounds have been reported. Since authors have reported contradictory results, the objective of this study was to investigate the effect of particles’ size in their toxicities. Methods: The human cell line A549 was exposed with magnetite iron oxide in two size categories of micro (≥5 µm) and nano (<100 nm), with four concentrations of 10, 50, 100, and 250 µg/ml at two time periods of 24 and 72 h. The cell viability, reactive oxygen species (ROS), changes in mitochondrial membrane potential, and incidence of apoptosis were studied. Results: Nano and micro magnetite particles demonstrated diverse toxicity effects on the A549 cell line at the 24- and 72-h exposure periods; however, the effects produced were time- and concentration-dependent. Nano magnetite particles produced greater cellular toxicities in forms of decreased viabilities at concentration exposures greater than 50 µg/ml ( p < 0.05), along with increased ROS ( p < 0.05), decreased cellular membrane potential ( p < 0.05), and reduced rate of apoptosis ( p < 0.05). Discussion: The results of this study demonstrated that magnetite iron in nano-range sizes had a greater absorbability for the A549 cell line compared to micro sizes, and at the same time, nanoparticles were more toxic than microparticles, demonstrating higher production of ROS and decreased viabilities. Considering the greater toxicity of nanoparticles of magnetite iron in this study, thorough precautionary control measures must be taken before they can be used in various industries.

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Acarbas, Ozge, et Macit Ozenbas. « Preparation of Iron Oxide Nanoparticles by Microwave Synthesis and Their Characterization ». Journal of Nanoscience and Nanotechnology 8, n^o 2 (1 février 2008) : 655–59. http://dx.doi.org/10.1166/jnn.2008.b268.

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In this study production of fine particle Fe2O3 via microwave processing of Fe(NO3)3·nH2O followed by low temperature annealing was reported. XRD was used to characterize the structural properties of nanoparticles. Approximate particle sizes were between 3–13 nm according to Scherrer's equation. Single point BET measurement results also show that samples have large surface area and they are nanometer sized particles. TEM study was conducted to examine the structure of the nanoparticles. TEM figure is in good agreement with the results obtained from Scherrer's equation using XRD spectra. In order to characterize the magnetic properties of the nanoparticles VSM (Vibrating Sample Magnetometer) was used. From these results it can be concluded that the sample containing only maghemite phase exhibits superparamagnetic behaviour, on the other hand sample containing both hematite and maghemite phases shows paramagnetic behaviour above 300 K, superparamagnetic behavior at lower temperatures.

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Duan, Yu Feng, et Zhao Xia Fu. « Preparation and Characterization of Magnetic Toner Particles by Direct Polymerization Method ». Advanced Materials Research 217-218 (mars 2011) : 1702–7. http://dx.doi.org/10.4028/www.scientific.net/amr.217-218.1702.

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In this study a kind of black toner, containing polymer, magnetic iron oxide pigment, and several other additives, was prepared by a suspension polymerization method. The morphology, influence factor of particle size, and glass transition of prepared toner were discussed. SEM image showed that the produced micron-sized particles have a spherical surface and the various chemicals were mixed into monomers during manufacturing of the particles. Discussion about particle formation and stability concluded that the toner particle size related with stabilizer concentration, stirrer speed, and crosslinking agent concentration. The bigger particles, resulted from droplets coalescence during polymerization process, disappeared when enough PVA stabilizer was used in the aqueous medium. .Increasing the stirrer speed corresponded to the decrease of the particles size. But any increase in stirrer speed t did not contribute to size reduction in small particles below 2μm. It was found that particle size decrease with the addition of crosslinking agent. The DSC result indicated the glass transition of polymerized toner could be effectively adjusted according to Fox equation through change the monomer ratio.

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Vershinina, Sofia F., et Vladimir I. Evtushenko. « Effect of intratumoral implantation of barium hexaferrite, magnetite, hematite, aluminium oxide and silica on the dynamics of Erlich tumor growth and survival value of tumor-carrying mice ». Medical academic journal 20, n^o 1 (22 juin 2020) : 75–82. http://dx.doi.org/10.17816/maj34107.

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Introduction. We have earlier shown antitumoral effect of barium hexaferrite implant BHF for models of two intratumoral transplantable solid tumor of mice LIO-1 and Erlich (2 sm3 tumors). In the mentioned work on the model of a rather big sized solid Erlich tumor (3 sm3) we have studied a comparative antitumoral effect after the implantation of BHF particles with a residual magnetic field of 150 mGsm referring to particles of iron oxides with residual magnetic field that was nearing to the zerohematite (Fe2O3) and magne tite (Fe3O4), and as well as for the control aluminium oxide (Al2O3) and silica (nSiO2 ∙ mH2O). Material and methods. Trials have been conducted with 70 white mice female mice with a mass of 2324 g. Malignant epithelial tumor of Erlich was intramuscularly transplanted into the right hind extremity. When tumors reached a size of 3 sm3, mice were divided into 6 groups whom BHF, magnetite, hematite, aluminium oxide, silica or physiologic saline were implanted, correspondingly. Results. As a result of the conducted studies it was found that BHF being implanted into a big-sized tumor (3 sm3) has a mild antitumoral effect for all the studies periods. Particles of iron oxides magnetite and hematite with a magnetic field nearing the zero did not possess the antitumor effect. By the end of experiment (29 days) in all groups including a control group, death of mice at 20 to 50 percent have been seen, and tumors were significantly necrotized, whereas in a group with implantation of silica into the tumor 100 percent of mice have survived and tumors itself did not have necrosis and had even pink colouring.

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Raschzok, Nathanael, Carolin M. Langer, Christian Schmidt, Karl H. Lerche, Nils Billecke, Kerstin Nehls, Natalie B. Schlüter et al. « Functionalizable Silica-Based Micron-Sized Iron Oxide Particles for Cellular Magnetic Resonance Imaging ». Cell Transplantation 22, n^o 11 (novembre 2013) : 1959–70. http://dx.doi.org/10.3727/096368912x661382.

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Ishikawa, Yoshie, Naoto Koshizaki et Alexander Pyatenko. « Submicrometer-sized Spherical Iron Oxide Particles Fabricated by Pulsed Laser Melting in Liquid ». IEEJ Transactions on Electronics, Information and Systems 135, n^o 9 (2015) : 1066–70. http://dx.doi.org/10.1541/ieejeiss.135.1066.

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Morris, D. G., et M. A. Muñoz-Morris. « Creep behaviour of iron–aluminium–chromium intermetallics strengthened by nano-sized oxide particles ». Materials Science and Engineering : A 607 (juin 2014) : 376–82. http://dx.doi.org/10.1016/j.msea.2014.04.018.

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ISHIKAWA, YOSHIE, NAOTO KOSHIZAKI et ALEXANDER PYATENKO. « Submicrometer-Sized Spherical Iron Oxide Particles Fabricated by Pulsed Laser Melting in Liquid ». Electronics and Communications in Japan 99, n^o 11 (18 octobre 2016) : 37–42. http://dx.doi.org/10.1002/ecj.11898.

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Zhang, Shuai, Gulijiazi Yeerkenbieke, Shuai Shi, Zhaoyang Wang, Lijin Yi et Xiaoxia Lu. « Adsorption of Pyrene and Arsenite by Micro/Nano Carbon Black and Iron Oxide ». Toxics 12, n^o 4 (29 mars 2024) : 251. http://dx.doi.org/10.3390/toxics12040251.

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Polycyclic aromatic hydrocarbons (PAHs) and arsenic (As) are common pollutants co-existing in the environment, causing potential hazards to the ecosystem and human health. How their behaviors are affected by micro/nano particles in the environment are still not very clear. Through a series of static adsorption experiments, this study investigated the adsorption of pyrene and arsenite (As (III)) using micro/nano carbon black and iron oxide under different conditions. The objectives were to determine the kinetics and isotherms of the adsorption of pyrene and As (III) using micro/nano carbon black and iron oxide and evaluate the impact of co-existing conditions on the adsorption. The microstructure of micro/nano carbon black (C 94.03%) is spherical-like, with a diameter of 100–200 nm. The micro/nano iron oxide (hematite) has irregular rod-shaped structures, mostly about 1 µm long and 100–200 nm wide. The results show that the micro/nano black carbon easily adsorbed the pyrene, with a pseudo-second-order rate constant of 0.016 mg/(g·h) and an adsorption capacity of 283.23 μg/g at 24 h. The micro/nano iron oxide easily adsorbed As (III), with a pseudo-second-order rate constant of 0.814 mg/(g·h) and an adsorption capacity of 3.45 mg/g at 24 h. The mechanisms of adsorption were mainly chemical reactions. Micro/nano carbon black hardly adsorbed As (III), but its adsorption capability for pyrene was reduced by the presence of As (III), and this effect increased with an increase in the As (III) concentration. The adsorbed pyrene on the micro/nano black carbon could hardly be desorbed. On the other hand, the micro/nano iron oxide could hardly adsorb the pyrene, but its adsorption capability for As (III) was increased by the presence of pyrene, and this effect increased with an increase in the pyrene concentration. The results of this study provide guidance for the risk management and remediation of the environment when there is combined pollution of PAHs and As.

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Yeh, Barry J., Tareq Anani et Allan E. David. « Improving the Size Homogeneity of Multicore Superparamagnetic Iron Oxide Nanoparticles ». International Journal of Molecular Sciences 21, n^o 10 (14 mai 2020) : 3476. http://dx.doi.org/10.3390/ijms21103476.

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Superparamagnetic iron oxide nanoparticles (SPIONs) have been widely explored for use in many biomedical applications. Methods for synthesis of magnetic nanoparticle (MNP), however, typically yield multicore structures with broad size distribution, resulting in suboptimal and variable performance in vivo. In this study, a new method for sorting SPIONs by size, labeled diffusive magnetic fractionation (DMF), is introduced as an improvement over conventional magnetic field flow fractionation (MFFF). Unlike MFFF, which uses a constant magnetic field to capture particles, DMF utilizes a pulsed magnetic field approach that exploits size-dependent differences in the diffusivity and magnetic attractive force of SPIONs to yield more homogenous particle size distributions. To compare both methods, multicore SPIONs with a broad size distribution (polydispersity index (PdI) = 0.24 ± 0.05) were fractionated into nine different-sized SPION subpopulations, and the PdI values were compared. DMF provided significantly improved size separation compared to MFFF, with eight out of the nine fractionations having significantly lower PdI values (p value < 0.01). Additionally, the DMF method showed a high particle recovery (>95%), excellent reproducibility, and the potential for scale-up. Mathematical models were developed to enable optimization, and experimental results confirmed model predictions (R2 = 0.98).

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Shabnam, R., M. A. Rahman, M. A. J. Miah, M. K. Sharafat, H. M. T. Islam, M. M. Rahman, M. A. Gafur et H. Ahmad. « Fabrication of Epoxide Functional Hydrophobic Composite Polymer Particles by Suspension Polymerization and Subsequent Doping with Fe³O⁴ Nanoparticles ». Journal of Scientific Research 9, n^o 3 (1 septembre 2017) : 329–39. http://dx.doi.org/10.3329/jsr.v9i3.31811.

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This investigation described a simple three-step process for the fabrication of micrometer-sized magnetic composite polymer particles. This composite polymer particle consisted of crosslinked hydrophobic poly(lauryl methacrylate-divinyl benzene) (P(LMA-DVB)) core, prepared by suspension polymerization. Then, P(LMA-DVB) copolymer core particles were coated with poly(glycidyl methacrylate) (PGMA) by seeded polymerization to introduce epoxide functionality. Finally, P(LMA-DVB)/PGMA composite particles were doped with iron oxide (Fe3O4) nanoparticles following in situ co-precipitation of Fe2+ and Fe3+ from their alkali aqueous solution. The presence of strained oxirane ring derived from PGMA segment present at the surface is expected to induce high affinity towards precipitated magnetic Fe3O4 nanoparticles. The compositional structure of P(LMA-DVB)/PGMA/Fe3O4 composite polymer particles was confirmed by Fourier Transform IR (FTIR), electron microscopy, thermogravimetry (TG), X-ray diffraction (XRD) and energy-dispersive X-ray (EDX).

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Guo, Chang, Ralf J. M. Weber, Alison Buckley, Julie Mazzolini, Sarah Robertson, Juana Maria Delgado-Saborit, Joshua Z. Rappoport et al. « Environmentally Relevant Iron Oxide Nanoparticles Produce Limited Acute Pulmonary Effects in Rats at Realistic Exposure Levels ». International Journal of Molecular Sciences 22, n^o 2 (8 janvier 2021) : 556. http://dx.doi.org/10.3390/ijms22020556.

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Iron is typically the dominant metal in the ultrafine fraction of airborne particulate matter. Various studies have investigated the toxicity of inhaled nano-sized iron oxide particles (FeOxNPs) but their results have been contradictory, with some indicating no or minor effects and others finding effects including oxidative stress and inflammation. Most studies, however, did not use materials reflecting the characteristics of FeOxNPs present in the environment. We, therefore, analysed the potential toxicity of FeOxNPs of different forms (Fe3O4, α-Fe2O3 and γ-Fe2O3) reflecting the characteristics of high iron content nano-sized particles sampled from the environment, both individually and in a mixture (FeOx-mix). A preliminary in vitro study indicated Fe3O4 and FeOx-mix were more cytotoxic than either form of Fe2O3 in human bronchial epithelial cells (BEAS-2B). Follow-up in vitro (0.003, 0.03, 0.3 µg/mL, 24 h) and in vivo (Sprague–Dawley rats, nose-only exposure, 50 µg/m3 and 500 µg/m3, 3 h/d × 3 d) studies therefore focused on these materials. Experiments in vitro explored responses at the molecular level via multi-omics analyses at concentrations below those at which significant cytotoxicity was evident to avoid detection of responses secondary to toxicity. Inhalation experiments used aerosol concentrations chosen to produce similar levels of particle deposition on the airway surface as were delivered in vitro. These were markedly higher than environmental concentrations. No clinical signs of toxicity were seen nor effects on BALF cell counts or LDH levels. There were also no significant changes in transcriptomic or metabolomic responses in lung or BEAS-2B cells to suggest adverse effects.

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Guo, Chang, Ralf J. M. Weber, Alison Buckley, Julie Mazzolini, Sarah Robertson, Juana Maria Delgado-Saborit, Joshua Z. Rappoport et al. « Environmentally Relevant Iron Oxide Nanoparticles Produce Limited Acute Pulmonary Effects in Rats at Realistic Exposure Levels ». International Journal of Molecular Sciences 22, n^o 2 (8 janvier 2021) : 556. http://dx.doi.org/10.3390/ijms22020556.

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Iron is typically the dominant metal in the ultrafine fraction of airborne particulate matter. Various studies have investigated the toxicity of inhaled nano-sized iron oxide particles (FeOxNPs) but their results have been contradictory, with some indicating no or minor effects and others finding effects including oxidative stress and inflammation. Most studies, however, did not use materials reflecting the characteristics of FeOxNPs present in the environment. We, therefore, analysed the potential toxicity of FeOxNPs of different forms (Fe3O4, α-Fe2O3 and γ-Fe2O3) reflecting the characteristics of high iron content nano-sized particles sampled from the environment, both individually and in a mixture (FeOx-mix). A preliminary in vitro study indicated Fe3O4 and FeOx-mix were more cytotoxic than either form of Fe2O3 in human bronchial epithelial cells (BEAS-2B). Follow-up in vitro (0.003, 0.03, 0.3 µg/mL, 24 h) and in vivo (Sprague–Dawley rats, nose-only exposure, 50 µg/m3 and 500 µg/m3, 3 h/d × 3 d) studies therefore focused on these materials. Experiments in vitro explored responses at the molecular level via multi-omics analyses at concentrations below those at which significant cytotoxicity was evident to avoid detection of responses secondary to toxicity. Inhalation experiments used aerosol concentrations chosen to produce similar levels of particle deposition on the airway surface as were delivered in vitro. These were markedly higher than environmental concentrations. No clinical signs of toxicity were seen nor effects on BALF cell counts or LDH levels. There were also no significant changes in transcriptomic or metabolomic responses in lung or BEAS-2B cells to suggest adverse effects.

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Mandal, Sujata, Dominic Savio, S. J. Selvaraj, S. Natarajan et Asit Baran Mandal. « Micro-Structural Properties of Zinc Oxide Nano-Particles Synthesized by Bio-Polymeric Templates ». Advanced Materials Research 906 (avril 2014) : 190–95. http://dx.doi.org/10.4028/www.scientific.net/amr.906.190.

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Zinc and iron oxide nanoparticles were synthesized using natural bio-polymeric templates viz. cellulose and sodium alginate. Cellulose fibres from different sources viz. filter-and blot-papers, were used as templates for this purpose. The synthesized Zinc oxide nanoparticles were characterized by X-ray diffraction (XRD), fourier transform infra-red spectra (FT-IR), UV-Visible spectrophotomer (UV-Vis) and scanning electron microscopic (SEM) studies. XRD studied confirmed the formation of highly crystalline hexagonal wurtzite phase of ZnO in all the synthesized nanoparticles. The average crystallite sizes of the nanoparticles obtained using different templates, were well below 50 nm. Characteristics of the zinc oxide nanoparticles obtained by template-based techniques were compared with those obtained by co-precipitation technique. Influence of various templates on the characteristics of metal oxide nanoparticles was studied.

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Cámara-Hinojosa, Alma, Darío Bueno-Baqués, Oliverio S. Rodríguez-Fernández et Ronald F. Ziolo. « Synthesis and Characterization of Magnetic Polyurethane Nanocomposite Foams ». Materials Science Forum 644 (mars 2010) : 29–32. http://dx.doi.org/10.4028/www.scientific.net/msf.644.29.

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New magnetic polyurethane nanocomposite foams have been synthesized by the one-shot method. The opened-cell soft foams contain a dispersion of uniformly sized nanocrystalline iron oxide prepared ex situ by the high temperature thermal decomposition of iron acetylacetonate in phenyl ether in the presence of oleic acid. The magnetic particles were dispersed in polyol by sonication prior to the reaction of the latter with isocyanate to produce the magnetic foams. A 7 wt% loading of iron oxide yielded a soft, flexible foam with a room temperature magnetization of 3.5 emu/g at one Tesla. Higher loadings of iron oxide are possible without destruction of the soft open-cell polyurethane structure. Physicochemical characterization of the foams will be presented along with magnetic and mechanical properties. Potential applications include smart materials such as magnetic shape memory foams, adhesive-free metal to foam seals, inductively coupled thermal foams and applications for conformable foams having a magnetic component such as healthcare products.

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Fuse, Hokuto, Naoto Koshizaki, Yoshie Ishikawa et Zaneta Swiatkowska-Warkocka. « Determining the Composite Structure of Au-Fe-Based Submicrometre Spherical Particles Fabricated by Pulsed-Laser Melting in Liquid ». Nanomaterials 9, n^o 2 (3 février 2019) : 198. http://dx.doi.org/10.3390/nano9020198.

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Submicrometre spherical particles made of Au and Fe can be fabricated by pulsed-laser melting in liquid (PLML) using a mixture of Au and iron oxide nanoparticles as the raw particles dispersed in ethanol, although the detailed formation mechanism has not yet been clarified. Using a 355 nm pulsed laser to avoid extreme temperature difference between two different raw particles during laser irradiation and an Fe2O3 raw nanoparticle colloidal solution as an iron source to promote the aggregation of Au and Fe2O3 nanoparticles, we performed intensive characterization of the products and clarified the formation mechanism of Au-Fe composite submicrometre spherical particles. Because of the above two measures (Fe2O3 raw nanoparticle and 355 nm pulsed laser), the products—whether the particles are phase-separated or homogeneous alloys—basically follow the phase diagram. In Fe-rich range, the phase-separated Au-core/Fe-shell particles were formed, because quenching induces an earlier solidification of the Fe-rich component as a result of cooling from the surrounding ethanol. If the particle size is small, the quenching rate becomes very rapid and particles were less phase-separated. For high Au contents exceeding 70% in weight, crystalline Au-rich alloys were formed without phase separation. Thus, this aggregation control is required to selectively form homogeneous or phase-separated larger submicrometre-sized particles by PLML.

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Bernad, Susan-Resiga et Bernad. « Hemodynamic Effects on Particle Targeting in the Arterial Bifurcation for Different Magnet Positions ». Molecules 24, n^o 13 (9 juillet 2019) : 2509. http://dx.doi.org/10.3390/molecules24132509.

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The present study investigated the possibilities and feasibility of drug targeting for an arterial bifurcation lesion to influence the host healing response. A micrometer sized iron particle was used only to model the magnetic carrier in the experimental investigation (not intended for clinical use), to demonstrate the feasibility of the particle targeting at the lesion site and facilitate the new experimental investigations using coated superparamagnetic iron oxide nanoparticles. Magnetic fields were generated by a single permanent external magnet (ferrite magnet). Artery bifurcation exerts severe impacts on drug distribution, both in the main vessel and the branches, practically inducing an uneven drug concentration distribution in the bifurcation lesion area. There are permanently positioned magnets in the vicinity of the bifurcation near the diseased area. The generated magnetic field induced deviation of the injected ferromagnetic particles and were captured onto the vessel wall of the test section. To increase the particle accumulation in the targeted region and consequently avoid the polypharmacology (interaction of the injected drug particles with multiple target sites), it is critical to understand flow hemodynamics and the correlation between flow structure, magnetic field gradient, and spatial position.

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Knier, Natasha N., Veronica P. Dubois, Yuanxin Chen, John A. Ronald et Paula J. Foster. « A method for the efficient iron-labeling of patient-derived xenograft cells and cellular imaging validation ». Journal of Biological Methods 8, n^o 3 (2 septembre 2021) : e154. http://dx.doi.org/10.14440/jbm.2021.356.

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There is momentum towards implementing patient-derived xenograft models (PDX) in cancer research to reflect the histopathology, tumor behavior, and metastatic properties observed in the original tumor. These models are more predictive of clinical outcomes and are superior to cell lines for preclinical drug evaluation and therapeutic strategies. To study PDX cells preclinically, we used both bioluminescence imaging (BLI) to evaluate cell viability and magnetic particle imaging (MPI), an emerging imaging technology to allow for detection and quantification of iron nanoparticles. The goal of this study was to develop the first successful iron labeling method of breast cancer cells derived from patient brain metastases and validate this method with imaging during tumor development. Luciferase expressing human breast cancer PDX cells (F2-7) were successfully labeled after incubation with micron-sized iron oxide particles (MPIO; 25 μg Fe/ml). NOD/SCID/ILIIrg−/− (n = 5) mice received injections of 1x106 iron-labeled F2-7 cells into the fourth mammary fat pad (MFP). BLI was performed longitudinally to day 49 and MPI was performed up to day 28. In vivo BLI revealed that signal increased over time with tumor development. MPI revealed decreasing signal in the tumor over time. Here, we demonstrate the first application of MPI to monitor the growth of a PDX MFP tumor. To accomplish this, we also demonstrate the first successful labeling of PDX cells with iron oxide particles. Imaging of PDX cells provides a powerful system to better develop personalized therapies targeting breast cancer brain metastasis.

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Golden, DC, JB Dixon et Y. Kanehiro. « The manganese oxide mineral, lithiophorite, in an oxisol From Hawaii ». Soil Research 31, n^o 1 (1993) : 51. http://dx.doi.org/10.1071/sr9930051.

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The mineralogical composition of the surface soil horizon (0-15 cm) of Wahiawa soil (Tropeptic Eutrustox) was investigated by X-ray diffraction (XRD), high gradient magnetic separation (HGMS), transmission electron microscopy (TEM), and infrared methods. The concentration of lithiophorite decreased with particle size and none was present in the clay fraction as indicated by XRD. Lithiophorite was further concentrated from the crushed sand-sized fraction by HGMS. Hexagonal, electron-dense, often twinned lithiophorite particles were identified by electron diffraction. Differential infrared (DIR) spectra obtained by dissolving Mn oxides in acidified hydroxylamine hydrochloride (HAHC) indicated lithiophorite as the HAHC-soluble Mn-phase. Lithiophorite compositiion, as revealed by chemical analysis of the HAHC extracts, consisted of appreciable amounts of Mn, Al, Zn, Co and Mg, and less than stoichiometric amounts of Li. Sodium hydroxide treatment apparently altered the lithiophorite, as revealed by the DIR spectrum of the hydroxylamine-soluble fraction of the NaOH-treated sample compared with the untreated sample. The high crystallinity of the lithiophorite was suggested by its resistance to chemical dissolution and narrow X-ray diffraction lines. No evidence for the presence of todorokite or birnessite was found, contrary to earlier reports. Examination of sand-sized nodules by scanning electron microscopy indicated large (2-5 �m) platy lithiophorite crystals at the surface of these nodules. Electron microprobe analysis of these platy particles indicated iron enrichment near the surface. The freshly fractured nodule surface revealed numerous unaltered platy crystals of lithiophorite filling the veins of the nodule.

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Banis, George, Emmanouela Mangiorou, Panagiota Tselou, Angelo Ferraro et Evangelos Hristoforou. « Magnetic Particles Retaining on Open and Closed Systems ». Key Engineering Materials 826 (octobre 2019) : 25–29. http://dx.doi.org/10.4028/www.scientific.net/kem.826.25.

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In recent decades the application of magnetic iron oxide micro-and nanoparticles has been established in various technological fields, such as magnetic separation of biomolecules and ions, biosensors, biofuel production and others [1-4]. Working with iron oxide particles is becoming main stream subject thanks to the facility that this kind of materials can be functionalized with a variety of chemical groups which confer them specific selective or catalytic properties [5]. Furthermore, iron oxide nanoparticles present magnetic properties, and in particular super-paramagnetism, which allows to remotely control them making their manipulation easy and cost-effective [6]. In addition, a new method of synthesis has been recently proposed, which can guarantee a cost-effective production of magnetic particles that may further reduce the running cost of separation methods based on magnetism [7]. Nevertheless, biotechnological applications of iron oxide particles are still confined to research level (lab scale devices) or for low throughput clinical applications [8,9]. Indeed, most systems based on the use of magnetic elements are design to work with microfluid dynamic or are able to process samples in bath-based fashion, therefore discontinuously. The need of robust and high-productive methods is demanded especially in bioscience where, independently from the reaction or process involving magnetic particles, once such composite materials are mixed or added to a given solution, inevitably at the end of workflow they must be separated/harvested from the reaction vessel. Therefore, it is vital for a good productivity and processivity of reactions involving magnetic particles to ensure that large volumes of solution can be treated, and magnetic particles withdrew in the most fast and accurate way. The purpose of this paper is to compare an open and a closed type magnetic trapping system regarding their efficiency using two different types of magnetic sources.

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Zambzickaite, Greta, Martynas Talaikis, Jorunas Dobilas, Voitech Stankevic, Audrius Drabavicius, Gediminas Niaura et Lina Mikoliunaite. « Microwave-Assisted Solvothermal Synthesis of Nanocrystallite-Derived Magnetite Spheres ». Materials 15, n^o 11 (5 juin 2022) : 4008. http://dx.doi.org/10.3390/ma15114008.

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The synthesis of magnetic particles triggers the interest of many scientists due to their relevant properties and wide range of applications in the catalysis, nanomedicine, biosensing and magnetic separation fields. A fast synthesis of iron oxide magnetic particles using an eco-friendly and facile microwave-assisted solvothermal method is presented in this study. Submicron Fe3O4 spheres were prepared using FeCl3 as an iron source, ethylene glycol as a solvent and reductor and sodium acetate as a precipitating and nucleating agent. The influence of the presence of polyethylene glycol as an additional reductor and heat absorbent was also evaluated. We reduce the synthesis time to 1 min by increasing the reaction temperature using the microwave-assisted solvothermal synthesis method under pressure or by adding PEG at lower temperatures. The obtained magnetite spheres are 200–300 nm in size and are composed of 10–30 nm sized crystallites. The synthesized particles were investigated using the XRD, TGA, pulsed-field magnetometry, Raman and FTIR methods. It was determined that adding PEG results in spheres with mixed magnetite and maghemite compositions, and the synthesis time increases the size of the crystallites. The presented results provide insights into the microwave-assisted solvothermal synthesis method and ensure a fast route to obtaining spherical magnetic particles composed of different sized nanocrystallites.

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Chen, Jiaqin, Mei Ming, Caili Xu, Jie Wu, Yi Wang, Ting Sun, Yun Zhang et Guangyin Fan. « Nanosized Iron Oxide Uniformly Distributed on 3D Carbon Nanosheets : Efficient Adsorbent for Methylene Blue ». Applied Sciences 9, n^o 14 (19 juillet 2019) : 2898. http://dx.doi.org/10.3390/app9142898.

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Magnetic carbon materials as adsorbents for dye removing have attracted increasing attention because of their magnetic separation feature. However, the immobilization of large magnetic particles on a carbon matrix greatly decreases the available sites for adsorption, resulting in a low adsorption capacity. The synthesis of magnetic carbon materials as adsorbents for dye adsorption with high adsorption capacity remains challenging. Herein, porous carbon (PC) was firstly synthesized through the calcination of macroporous acrylic type cation exchange resin. The as-prepared PC was applied as a matrix to deposit nano-sized Fe3O4 nanoparticles (MPC) via a facile one-pot solvothermal strategy. The nano-sized Fe3O4 nanoparticles (5.19 nm in diameter) are uniformly distributed on the PC surface. The MPC possesses an exceptional performance for methylene blue removal (qe = 214.4 mg g−1) at room temperature, outperforming most previous magnetic carbon adsorbents. The large surface area of the MPC originated from the combined advantages of PC and nano-sized Fe3O4 must be ascribed to the high performance of MPC composite toward methylene blue adsorption.

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Shahgaldi, Samaneh, Zahira Yaakob, Norazrina Mat Jali, Dariush Jafar Khadem, Wan Ramli Wan Daud et Edy Herianto Majlan. « Influence of Iron Oxide Nano Particles on Electrospun Poly (Vinylidene Fluride)-Based Carbon Nanofibers on Hydrogen Storage ». Key Engineering Materials 471-472 (février 2011) : 1184–89. http://dx.doi.org/10.4028/www.scientific.net/kem.471-472.1184.

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Electrospun Poly (vinylidene fluoride) (PVdF) fine fiber of 100-300 nm in diameter in ribbon shape was synthesized through the electrospinning process via sol-gel. In order to synthesize infusible nanofibers all processing of dehydrofluorination and carbonization was investigated. Iron nanoparticles was doped with PVDF nanofibers in order to be effective in surface area, and porosity to increase the hydrogen storage. The composition, morphology, structure and surface area of PVDF/Iron Oxide nanofibers were investigated by thermo gravimetric analysis (TGA) to determinate the temperature of possible decomposition and crystallinity, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Micromeritics (ASAP2020) used to study the textural properties of the sample, like surface area, total pore volume, and micro pore volume. The result shows that the PVDF without dehydrofluorination treatment for infusibility become melt at around 160 °C. By adding the iron oxide nanoparticles as a catalyst it can improve the characteristic of the carbon fiber for hydrogen storage. In best of our knowledge, PVDF doping with iron oxide investigated for first time.

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