The role of polymer films on the oxidation of magnetite nanoparticles

Letti, Camila J.; Paterno, Leonardo G.; Pereira-da-Silva, Marcelo A.; Morais, P.C.; Soler, Maria A. G.

doi:10.1016/j.jssc.2016.10.027

Cited by 21 publications

(18 citation statements)

References 49 publications

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“…We assume that the peak at 487 cm −1 is a mix of the T 2g (2) mode of magnetite and E g mode of maghemite. The band at about 712 cm −1 is the sign of the A 1g mode of maghemite [ 64 , 66 ], which may be due to the oxidation of magnetite to maghemite, which occurs more actively at low laser intensity [ 64 ], as in the case of our experiment. Further, for the samples synthesized at high temperatures, the peak at 712 cm −1 is separated from the peak of magnetite and has a lower intensity.…”

Section: Resultsmentioning

confidence: 64%

“…The peaks observed at 190 and 570 cm −1 , which is more clearly observed with an increase of particle size, confirm the phase of magnetite and are assigned to T 2g (1) and T 2g (3) modes [ 62 , 63 ], respectively. The position of the peak at 487 cm −1 corresponds to the T 2g (2) mode of magnetite [ 64 , 65 ]; however, this peak should be weaker than that shown in Figure 3 . We assume that the peak at 487 cm −1 is a mix of the T 2g (2) mode of magnetite and E g mode of maghemite.…”

Section: Resultsmentioning

confidence: 99%

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Magnetic and Magneto-Optical Oroperties of Iron Oxides Nanoparticles Synthesized under Atmospheric Pressure

et al. 2020

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Magnetite nanoparticles were synthesized by a simple thermal decomposition process, involving only iron (III) nitrate nonahydrate as a precursor, and hexadecylamine as a solvent and stabilizer at reaction temperatures varied from 200 to 380 °C. The results of the structural analysis showed that the average crystallite size depends on the reaction temperature and increases from 4.8 to 13.3 nm. The behavior of the coercivity indicates that all synthesized samples are single domain; herewith, it was found that the critical size corresponding to the transition to the superparamagnetic state at room temperature is about 9 nm. The effect of the reaction temperature on changes in the saturation magnetization was studied. It was found that the size effect in the MCD spectra is observed for the IVCT transition and one ISCT transition, and the influence of the reaction temperature on the change in the MCD spectra was discussed.

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Section: Resultsmentioning

confidence: 64%

Section: Resultsmentioning

confidence: 99%

Magnetic and Magneto-Optical Oroperties of Iron Oxides Nanoparticles Synthesized under Atmospheric Pressure

et al. 2020

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“…The saturation magnetization was found to be 38.2 emu/g, 30.5 emu/g and 36.9 emu/g for rGO-Fe 3 O 4 , rGO-PDA@Fe 3 O 4 and c-rGO-PDA@Fe 3 O 4 aerogel samples, respectively. It was generally expected that covering the Fe 3 O 4 nanoparticles with an organic (PDA) shell will increase the magnetization of the samples [61], thanks to the protection of the magnetite surface from an environmental oxidation [62–64]. However, the saturation magnetization of rGO-PDA@Fe 3 O 4 with respect to the rGO-Fe 3 O 4 was decreased, which is due to additional contribution of PDA to the sample volume [65].…”

Section: Resultsmentioning

confidence: 99%

Anchoring Fe₃O₄ nanoparticles in a reduced graphene oxide aerogel matrix via polydopamine coating

Scheibe

Mrówczyński

Michalak

et al. 2018

Beilstein J. Nanotechnol.

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Reduced graphene oxide–magnetite hybrid aerogels attract great interest thanks to their potential applications, e.g., as magnetic actuators. However, the tendency of magnetite particles to migrate within the matrix and, ultimately, escape from the aerogel structure, remains a technological challenge. In this article we show that coating magnetite particles with polydopamine anchors them on graphene oxide defects, immobilizing the particles in the matrix and, at the same time, improving the aerogel structure. Polydopamine coating does not affect the magnetic properties of magnetite particles, making the fabricated materials promising for industrial applications.

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“…7 This composite has a complex mechanism of interaction with the 3d orbital of Au atom in the substrate, which could change the surface plasmonic effect because of the adsorption the composite film causing a shift of the SPR angle, reducing the θ values close to 45 . 7,17,29,30 The refraction angles of each bilayer in the LbL film architecture were structured in Table 2.…”

Section: Interaction Study By Sprmentioning

confidence: 99%

An investigation of the synergistic effect between magnetite nanoparticles and polypyrrole in nanostructured layer‐by‐layer films

Lima

Maciel

Ferreira

et al. 2020

J of Applied Polymer Sci

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In this paper, we report the controlled fabrication of layer-by-layer (LbL) films deposited on gold substrates with three different supramolecular architectures using polypyrrole (Ppy) and magnetite nanoparticles (Fe 3 O 4-np), besides conventional poly(allylamine hydrochloride) (PAH) e poly(vinyl sulfonic acid) (PVS) polyelectrolytes, demonstrating the synergistic effect between Ppy and Fe 3 O 4-np such as a result of their interaction. Modified gold electrodes were analyzed by contact angle (wettability), surface plasmon resonance (SPR), raman spectroscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. The (Fe 3 O 4-np/Ppy) 3 architecture was also evaluated by scanning electron microscopy. The modified gold electrodes present more homogeneous covering, higher electron transfer and a decrease of resistance with the incorporation of the nanostructured materials such as Ppy and Fe 3 O 4-np forming (Fe 3 O 4-np/Ppy) 3 LbL film. The results carried out in this study suggest that the (Fe 3 O 4-np/Ppy) 3 LbL film can be applied as a possible electrochemical or optical non-enzymatic sensor for analytical detection.

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The role of polymer films on the oxidation of magnetite nanoparticles

Cited by 21 publications

References 49 publications

Magnetic and Magneto-Optical Oroperties of Iron Oxides Nanoparticles Synthesized under Atmospheric Pressure

Magnetic and Magneto-Optical Oroperties of Iron Oxides Nanoparticles Synthesized under Atmospheric Pressure

Anchoring Fe₃O₄ nanoparticles in a reduced graphene oxide aerogel matrix via polydopamine coating

An investigation of the synergistic effect between magnetite nanoparticles and polypyrrole in nanostructured layer‐by‐layer films

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The role of polymer films on the oxidation of magnetite nanoparticles

Cited by 21 publications

References 49 publications

Magnetic and Magneto-Optical Oroperties of Iron Oxides Nanoparticles Synthesized under Atmospheric Pressure

Magnetic and Magneto-Optical Oroperties of Iron Oxides Nanoparticles Synthesized under Atmospheric Pressure

Anchoring Fe3O4 nanoparticles in a reduced graphene oxide aerogel matrix via polydopamine coating

An investigation of the synergistic effect between magnetite nanoparticles and polypyrrole in nanostructured layer‐by‐layer films

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Anchoring Fe₃O₄ nanoparticles in a reduced graphene oxide aerogel matrix via polydopamine coating