Influence of Surface Treatment on Magnetic Properties of Fe3O4 Nanoparticles Synthesized by Electrochemical Method.
22 Jun 2016-Journal of Physical Chemistry B (American Chemical Society)-Vol. 120, Iss: 27, pp 6634-6645
TL;DR: The changes of magnetic properties in magnetite nanoparticles during two different stabilization processes were investigated and showed that the uncoated and coated MNPs had a narrow size distribution and the saturation magnetization values showed dependence on the magnetite synthesis conditions and surface modifiers.
Abstract: The changes of magnetic properties in magnetite nanoparticles during two different stabilization processes were investigated. Magnetic nanoparticles (MNPs) were obtained by electrochemical synthesis from two kinds of salts: (CH3)4NCl and NaCl. After that, two methods—steric and electrostatic—were used to stabilize MNPs with oleic acid (OA) and sodium hydroxide (NaOH), respectively. As a consequence, aqueous and organic dispersions were obtained after surface modification. The coated nanoparticles were characterized by TEM, zeta potential, thermogravimetry analysis (TGA), cyclic voltammetry (CV), magnetization measurements, and infrared and Mossbauer spectroscopy. The results showed that the particles were between 8 and 13 nm in size. In addition, the MNPs were coated with negative charge layers from NaOH by physisorption and coated with carboxylate groups from OA by the chemisorption process, and hence, they exhibited different reactivity and behavior depending on the nature of the electrolyte used in the...
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TL;DR: In this article, the oxidation process of magnetite to maghemite is investigated under mild and harsh conditions in order to understand the oxidation behavior and the chemical stability of transition forms, and the multi-analytical approach allows new insights into surface composition and rearrangement according to respective different depth profiles.
Abstract: Iron oxide nanoparticles are of great scientific interest due to their huge versatility of applications. The oxidation process of magnetite to maghemite is difficult to monitor as both iron oxide polymorphs possess connatural chemical properties. Especially the surface composition and reactivity of these nanosystems, which are most relevant for interactions with their environment, are not completely understood. Here, the oxidation of magnetite is investigated under mild and harsh conditions in order to understand the oxidation behaviour and the chemical stability of transition forms. Therefore, the oxidation process, is investigated with Raman, Mossbauer and X-ray photoelectron spectroscopy as well as X-ray diffraction and magnetometry. The multi-analytical approach allows new insights into surface composition and rearrangement according to respective different depth profiles. For both conditions investigated, the ferrous iron components are oxidised prior to structural changes in the Fe–O vibrations and crystal structure. The process starts from the outer layers and is acid catalysed. Oxidation leads to a decrease of magnetisation which still remains higher than 54 emu g−1. The charge and surface reactivity can be affected by the different oxidation methods and the irreversible adsorption of acid molecules. Biocompatibility and catalytic properties of iron oxide nanoparticles open doors to future applications.
137 citations
TL;DR: Interestingly, CGFe3O4NPs exhibit a stupendous bactericidal action against different human pathogens which depicts its antimicrobial value.
Abstract: In the present study, a sustainable green chemistry approach was established to fabricate magnetic Fe3O4 nanoparticles (Fe3O4NPs) using the aqueous fruit extract of edible C guianensis (CGFE) Synthesized NPs were further confirmed with different high-throughput characterization techniques such as UV–visible spectroscopy, FT-IR, XPS, DLS and zeta potential analysis Additionally, XRD, AFM, HRTEM and SQUID VSM demonstrate the generation of crystalline CGFe3O4NPs with mean diameter of 17 ± 10 nm Interestingly, CGFe3O4NPs exhibit a stupendous bactericidal action against different human pathogens which depicts its antimicrobial value A significant dose-dependent cytotoxic effect of CGFe3O4NPs was noticed against treated human hepatocellular carcinoma cells (HepG2)
110 citations
Cites background from "Influence of Surface Treatment on M..."
...The mean particle size was 17 nm with the standard deviation of 10, it was quite close to the calculated crystallite size of 7 nm, suggesting that the majority of the observed spherical nanoparticles might be single crystals [40]....
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TL;DR: Magnetic hyperthermia measurements and Monte Carlo-based simulations support the observed SAR trend and reveal the importance of the dipolar interaction effect and its dependence on the details of the particle arrangements within the different clusters.
Abstract: Magnetic hyperthermia (MH) based on magnetic nanoparticles (MNPs) is a promising adjuvant therapy for cancer treatment. Particle clustering leading to complex magnetic interactions affects the heat generated by MNPs during MH. The heat efficiencies, theoretically predicted, are still poorly understood because of a lack of control of the fabrication of such clusters with defined geometries and thus their functionality. This study aims to correlate the heating efficiency under MH of individually coated iron oxide nanocubes (IONCs) versus soft colloidal nanoclusters made of small groupings of nanocubes arranged in different geometries. The controlled clustering of alkyl-stabilized IONCs is achieved here during the water transfer procedure by tuning the fraction of the amphiphilic copolymer, poly(styrene-co-maleic anhydride) cumene-terminated, to the nanoparticle surface. It is found that increasing the polymer-to-nanoparticle surface ratio leads to the formation of increasingly large nanoclusters with define...
92 citations
TL;DR: In this article, a green synthesis of Fe3O4 nanoparticles using Kappaphycus alvarezii plant extract green method with efficient hot plate combustion method is presented.
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TL;DR: Synthesized IONPs and specially those functionalized with silica, chitosan and Tris presented comparable desorption percentages with some reported studies in plasmid DNA separation and can be considered for DNA extraction and purification from complex biological samples.
35 citations
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TL;DR: A novel water-dispersible oleic acid-Pluronic-coated iron oxide magnetic nanoparticle formulation that can be loaded easily with high doses of water-insoluble anticancer agents and demonstrated sustained intracellular drug retention relative to drug in solution and a dose-dependent antiproliferative effect in breast and prostate cancer cell lines.
Abstract: We have developed a novel water-dispersible oleic acid (OA)-Pluronic-coated iron oxide magnetic nanoparticle formulation that can be loaded easily with high doses of water-insoluble anticancer agents Drug partitions into the OA shell surrounding iron oxide nanoparticles, and the Pluronic that anchors at the OA−water interface confers aqueous dispersity to the formulation Neither the formulation components nor the drug loading affected the magnetic properties of the core iron oxide nanoparticles Sustained release of the incorporated drug is observed over 2 weeks under in vitro conditions The nanoparticles further demonstrated sustained intracellular drug retention relative to drug in solution and a dose-dependent antiproliferative effect in breast and prostate cancer cell lines This nanoparticle formulation can be used as a universal drug carrier system for systemic administration of water-insoluble drugs while simultaneously allowing magnetic targeting and/or imaging Keywords: Sustained release; wat
870 citations
TL;DR: In this paper, Oleic acid (OA)-coated magnetite nanoparticles of 7 and 19 µm were obtained by the seed-mediated high temperature thermal decomposition of iron(III) acetylacetonate (Fe(acac) 3 ) precursor method.
859 citations
TL;DR: The results show that the particle size as well as the magnetization of the MNPs was very much dependent on pH, initial temperature of Fe2+ and Fe3+ solutions and steering speed.
Abstract: Superparamagnetic iron oxide nanoparticles (MNPs) with appropriate surface chemistry exhibit many interesting properties that can be exploited in a variety of biomedical applications such as magnetic resonance imaging contrast enhancement, tissue repair, hyperthermia, drug delivery and in cell separation. These applications required that the MNPs such as iron oxide Fe3O4 magnetic nanoparticles (Fe3O4 MNPs) having high magnetization values and particle size smaller than 100 nm. This paper reports the experimental detail for preparation of monodisperse oleic acid (OA)-coated Fe3O4 MNPs by chemical co-precipitation method to determine the optimum pH, initial temperature and stirring speed in order to obtain the MNPs with small particle size and size distribution that is needed for biomedical applications. The obtained nanoparticles were characterized by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray fluorescence spectrometry (EDXRF), thermogravimetric analysis (TGA), X-ray powder diffraction (XRD), and vibrating sample magnetometer (VSM). The results show that the particle size as well as the magnetization of the MNPs was very much dependent on pH, initial temperature of Fe2+ and Fe3+ solutions and steering speed. The monodisperse Fe3O4 MNPs coated with oleic acid with size of 7.8 ± 1.9 nm were successfully prepared at optimum pH 11, initial temperature of 45 °C and at stirring rate of 800 rpm. FTIR and XRD data reveal that the oleic acid molecules were adsorbed on the magnetic nanoparticles by chemisorption. Analyses of TEM show the oleic acid provided the Fe3O4 particles with better dispersibility. The synthesized Fe3O4 nanoparticles exhibited superparamagnetic behavior and the saturation magnetization of the Fe3O4 nanoparticles increased with the particle size.
639 citations
TL;DR: In this paper, the particles have been suspended in non-aqueous and aqueous media by coating the particles with a single layer and a bilayer of oleic acid, respectively.
554 citations