A new method for the identification and quantification of magnetite–maghemite mixture using conventional X-ray diffraction technique

Kim, Wonbaek; Suh, Chang–Yul; Cho, Sung-Wook; Roh, Ki‐Min; Kwon, Hanjung; Song, Kyung Soon; Shon, In-Jin

doi:10.1016/j.talanta.2012.03.001

Cited by 312 publications

(158 citation statements)

References 39 publications

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“…This selected sample presents the best yield of functionalization. Crystallographic peaks and Miller indices found in the sample, which are reported in literature (Kim et al, 2012), were 21.4 ° (111), 35.2 ° (220), 41.6 ° (311), 50.7 ° (400) 63.2 ° (422), 67.5 ° (511) and 74.4 ° (440). These data are related to the cubic crystal system Fd-3m (227) space group that represents the characteristics of the unit cell of magnetite spinel, showing that the nanoparticles synthesized in this study are Fe3O4.…”

Section: Functionalization Methods and Biocatalyst Selectionsupporting

confidence: 74%

NANOBIOCATALYTIC SYSTEMS BASED ON LIPASE-Fe3O4 AND CONVENTIONAL SYSTEMS FOR ISONIAZID SYNTHESIS: A COMPARATIVE STUDY

Costa

Souza

Fechine

et al. 2016

Braz. J. Chem. Eng.

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-Superparamagnetic nanomaterials have attracted interest in many areas due to the high saturation magnetization and surface area. For enzyme immobilization, these properties favor the enzyme-support contact during the immobilization reaction and easy separation from the reaction mixture by use of low-cost magnetic processes. Iron oxide magnetic nanoparticles (Fe3O4, MNPs), produced by the co-precipitation method, functionalized with 3-aminopropyltriethoxysilane (APTES) and glutaraldehyde (GLU), were evaluated as a solid support for Candida antarctica lipase B (CALB) immobilization. The nanomagnetic derivative (11nm) obtained after CALB immobilization (MNPs/APTES/GLU/CALB) was evaluated as biocatalyst in isoniazide (INH) synthesis using ethyl isonicotinate (INE) and hydrazine hydrate (HID) as substrates, in 1,4-dioxane. The results showed that MNPs/APTES/CALB had a similar performance when compared to a commercial enzyme Novozym 435, showing significant advantages over other biocatalysts, such as Rhizhomucor miehei lipase (RML) and CALB immobilized on non-conventional, low-cost, chitosan-based supports.

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Section: Functionalization Methods and Biocatalyst Selectionsupporting

confidence: 74%

NANOBIOCATALYTIC SYSTEMS BASED ON LIPASE-Fe3O4 AND CONVENTIONAL SYSTEMS FOR ISONIAZID SYNTHESIS: A COMPARATIVE STUDY

Costa

Souza

Fechine

et al. 2016

Braz. J. Chem. Eng.

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“…An indirect indication can be obtained from the shape of the high-angle peaks (5 1 1) and (4 4 0). It has been shown by Kim et al [47] that these peaks are doublets in case of mixture of magnetite (Fe 3 O 4 ) and maghemite ( -Fe 2 O 3 ) phases; for example, the maximum of the (5 1 1) mixture, the intensity of each of these peaks varies, depending on the concentration of the corresponding oxide. The experimental data of each of the (5 1 1) and (4 0 0) peaks in Figure 5 were successfully fitted with a single symmetric peak with maximum at 57.3 ∘ and 62.8 ∘ , respectively, which is an indirect indication for formation of -Fe 2 O 3 attached to the CNF during the synthesis.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of Carbon Nanofibers with Maghemite via a Modified Sol-Gel Technique

Silva

Salas

Nedev

et al. 2017

Journal of Nanomaterials

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Carbon nanohybrid material (CNF/ -Fe 2 O 3 ) was obtained via a modified sol-gel technique consisting of two steps: functionalization of carbon nanofibers (CNF) in H 2 SO 4 /HNO 3 followed by synthesis using Fe(NO 3 ) 3 •9H 2 O. As a result, the iron content of the CNF/ -Fe 2 O 3 was increased by more than twice from about 40% to about 87% mass percent, compared to the pristine CNF and oxidized CNF specimens, as proved by energy dispersive X-ray fluorescence. Scanning electron microscopy images exhibited "cumulus" on the CNF/ -Fe 2 O 3 specimen surface, which showed the highest iron mass percentage, proved by energy dispersive X-ray spectroscopy. Transmission electron microscopy images confirmed attachment of -Fe 2 O 3 cumulus to the inner and outer surfaces of the CNF walls after synthesis. The characteristic peaks of Fe 2p 3/2 and Fe 2p 1/2 appeared in the XPS spectra obtained on CNF/ -Fe 2 O 3 . In addition, X-ray diffraction (XRD) results indicated formation of -Fe 2 O 3 during the synthesis process. The Raman spectrum of the CNF/ -Fe 2 O 3 sample displays peaks with positions close to characteristic peaks of highly crystalline and monodisperse maghemite nanocrystallites. The synthesis of CNF/ -Fe 2 O 3 leads to an increase in the hydrophilicity of CNF and magnetic properties at room temperature.

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“…79196) with a lattice parameter of 8.349 Å. As it was mentioned in previous studies on identification and quantification of magnetite-maghemite mixture using conventional X-ray diffraction technique carried out by W. Kim et al [29], the magnetite and maghemite phases are difficult to differentiate when they coexist because they are very close. The lattice parameter calculated from the pattern play an important role in the establishment the magnetite or maghemite phase.…”

Section: Discussionmentioning

confidence: 99%

Synthesis, Characterization, and Toxicity Evaluation of Dextran-Coated Iron Oxide Nanoparticles

Balaș

Ciobanu

Burtéa

et al. 2017

Metals

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Abstract:We report the synthesis of dextran-coated iron oxide magnetic nanoparticles (DIO-NPs) with spherical shape and uniform size distribution as well as their accumulation and toxic effects on Jurkat cells up to 72 h. The characterization of dextran-coated maghemite nanoparticles was done by X-ray diffraction and dynamic light scattering analyses, transmission electron microscopy imaging, attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, magnetic hysteresis, and relaxometry measurements. The quantification of DIO-NPs intracellular uptake showed a progressive accumulation of iron as a function of time and dose accompanied by additional lysosome formation and an increasing darkening exhibited by a magnetic resonance imaging (MRI) scanner. The cytotoxicity assays revealed a decrease of cell viability and a loss of membrane integrity in a time-and dose-dependent manner. Exposure to DIO-NPs determined an increase in reactive oxygen species level up to 72 h. In the first two days of exposure, the level of reduced glutathione decreased and the amount of malondyaldehyde increased, but at the end of the experiment, their concentrations returned to control values. These nanoparticles could be used as contrast agents for MRI but several parameters concerning their interaction with the cells should be taken into consideration for a safe utilization.

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A new method for the identification and quantification of magnetite–maghemite mixture using conventional X-ray diffraction technique

Cited by 312 publications

References 39 publications

NANOBIOCATALYTIC SYSTEMS BASED ON LIPASE-Fe3O4 AND CONVENTIONAL SYSTEMS FOR ISONIAZID SYNTHESIS: A COMPARATIVE STUDY

NANOBIOCATALYTIC SYSTEMS BASED ON LIPASE-Fe3O4 AND CONVENTIONAL SYSTEMS FOR ISONIAZID SYNTHESIS: A COMPARATIVE STUDY

Synthesis of Carbon Nanofibers with Maghemite via a Modified Sol-Gel Technique

Synthesis, Characterization, and Toxicity Evaluation of Dextran-Coated Iron Oxide Nanoparticles

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