Magnetic investigation of iron-nitride-based magnetic fluid

Teixeira, Cimei Borges; Filho, Olavo Leopoldino da Silva; Neto, K. Skeff; Morais, P.C.

doi:10.1007/s10751-008-9596-x

Cited by 6 publications

(6 citation statements)

References 9 publications

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“…The resultant C@Fe 2 O 3 –GO powder was then ground with melamine and pyrolyzed at 900 °C, during which Fe 2 O 3 –GO got reduced by carbon, forming metallic Fe atoms that are chemically active and can react with N and C atoms to give Fe 3 C and Fe–N x . , Fe–N x means coordination between Fe and N atoms. Actually, due to the harsh formation conditions of iron nitride (FeN x ), − FeN x cannot be formed under the synthetic conditions adopted in this work. Meanwhile, the ammonia gas generated from melamine can corrode the carbon substrate at 900 °C, forming a porous carbon network, which can facilitate Li + transport and improve the reaction kinetics of the Li–S battery; it also provides a three-dimensional conductive network, which can accelerate electron transport to improve the utilization of sulfur.…”

Section: Results and Discussionmentioning

confidence: 99%

Nitrogen-Doped Porous Carbon Networks with Active Fe–N_x Sites to Enhance Catalytic Conversion of Polysulfides in Lithium–Sulfur Batteries

Yang

Zhang

et al. 2019

ACS Appl. Mater. Interfaces

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The practical development of lithium–sulfur (Li–S) batteries is largely obstructed by their poor cycling stability due to the shuttling effect of soluble polysulfides. To address this issue, we herein report an interconnected porous N-doped carbon network (NPCN) incorporating Fe3C nanoparticles and Fe–N x moieties, which is used for separator modification. The NPCN can facilitate lithium ion and electron transport and localize polysulfides within the separator’s cathode side due to strong chemisorption; the Fe3C/Fe–N x species also provides chemical adsorption to trap polysulfides and Fe3C catalyzes the redox conversion of polysulfides. More importantly, the catalysis effect of Fe3C is promoted by the presence of Fe–N x coordination sites as indicated by the enhanced redox current in cyclic voltammetry. Due to the above synergistic effects, the battery with the Fe3C/Fe–N x @NPCN modified separator exhibits high capacity and good cycling performance: at a current density of 0.1C, it yields a high capacity of 1517 mAh g–1 with 1.2 mg cm–2 sulfur loading and only experiences a capacity decay rate of 0.034% per cycle after 500 cycles at 1C; it also delivers a good capacity of 683 mAh g–1 at 0.1C with a high sulfur loading of 5.0 mg cm–2; after 200 cycles, the battery capacity can still reach 596 mAh g–1, corresponding to 87% capacity retention. Our work provides a new and effective strategy to achieve the catalytic conversion of polysulfide and is beneficial for the development of rechargeable Li–S batteries.

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Section: Results and Discussionmentioning

confidence: 99%

Nitrogen-Doped Porous Carbon Networks with Active Fe–N_x Sites to Enhance Catalytic Conversion of Polysulfides in Lithium–Sulfur Batteries

Yang

Zhang

et al. 2019

ACS Appl. Mater. Interfaces

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“…Diamagnetic materials are also used in the synthesis of inverse FFs. As of now, different metals (Fe, Co, Ni, Gd), metal nitrides such as iron nitride (Fe x N), metal oxides (Fe 3 [2,29,[40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55] Metallic FFs based on mercury prepared by suspending alloy particles of FeÀB, FeÀCoÀB, FeÀNiÀB, and CoÀB have also been synthesized by the reduction of transition-metal ions in aqueous solutions using NaBH 4 in mercury. [42] Even though the choice of magnetic material is wide, its proper compatibility with the surfactant and carrier medium is essential for enhancing the suspension stability.…”

Section: Synthesis Of Ferrofluidsmentioning

confidence: 99%

“…[55] In the case of spherical particles with a coating thickness s, the modified interaction parameter is expressed as l* = l(d/d+2s) 3 . [202] For nonspherical particles, d is replaced by the distance between the two centers of particles in contact.…”

Section: Interaction Parameter and Dipolar Interactionsmentioning

confidence: 99%

“…The interparticle interaction in FFs is expressed by the interaction parameter (l) as l = m 0 M 0 2 V 2 /2 pd 3 k B T, in which m 0 is the vacuum permeability, M 0 is the spontaneous magnetization of the magnetic material, V is its volume, d is the particle diameter, k B is the Boltzmann constant, and T is the absolute temperature. [55] In the case of spherical particles with a coating thickness s, the modified interaction parameter is expressed as l* = l(d/d+2s) 3 . [202] For nonspherical particles, d is replaced by the distance between the two centers of particles in contact.…”

Section: Interaction Parameter and Dipolar Interactionsmentioning

confidence: 99%

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Ferrofluids: Synthetic Strategies, Stabilization, Physicochemical Features, Characterization, and Applications

Joseph

Mathew

2014

ChemPlusChem

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Ferrofluids (FFs) or magnetic nanofluids are incredible smart materials consisting of ultrafine magnetic nanoparticles suspended in a liquid carrier medium, which exhibit both fluidity and magnetic controllability. Studies involving the dynamics and physicochemical properties of these magnetic nanofluids are an interdisciplinary area of research attracting researchers from different fields of science and technology. Herein, a comprehensive Review on the different aspects of FF research is presented. First, the synthesis and stabilization of various types of FFs are discussed followed by their physicochemical features such as polydispersity, magnetic behavior, dipolar interactions, formation of chainlike aggregates, and long‐range ordering. The Review also details the rheological and thermal properties, dynamic instabilities, phase behavior, and particle assemblies in FFs to form complex multipolar geometries, photonic nanostructures, labyrinth structures, thin films, and droplets. Many important characterization techniques for probing FF properties are also briefly discussed, and the numerous innovative applications and future prospects of FFs are outlined.

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“…Significantly, the possibility of heterogeneous structure formation is decided by interparticle interactions in ferrofluids, which is expressed by the value of the interaction parameter ( λ ′) [ 42 ], as it expresses the interaction between magnetic nanoparticles resulting from the balance of magnetic and thermal energies [ 43 ]. If λ ′ < 1, the Brownian motion dominates in the ferrofluids, making it homogeneous with no field-induced structures.…”

Section: Introductionmentioning

confidence: 99%

Investigation of the Rheological Properties of Zn-Ferrite/Perfluoropolyether Oil-Based Ferrofluids

Chen

Liu

et al. 2021

Nanomaterials

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The rheological properties of ferrofluids are related to various applications, such as sealing and loudspeakers, and have therefore attracted widespread attention. However, the rheological properties and their influence on the mechanisms of perfluoropolyether oil (PFPE oil)-based ferrofluids are complicated and not clear. Here, a series of PFPE oil-based ferrofluids were synthesized via a chemical co-precipitation method, and their rheological properties were revealed, systematically. The results indicate that the prepared Zn-ferrite particles have an average size of 12.1 nm, within a range of 4–18 nm, and that the ferrofluids have excellent dispersion stability. The activity of the ferrofluids changes from Newtonian to non-Newtonian, then to solid-like with increasing w from 10 wt% to 45.5 wt%, owing to their variation in microstructures. The viscosity of the ferrofluids increases with increasing Mw (the molecular weight of base liquid PFPE oil polymer), attributed to the increase in entanglements between PFPE oil molecules. The magnetization temperature variation of Zn-ferrite nanoparticles and viscosity temperature variation of PFPE oil together contribute to the viscosity temperature change in ferrofluids. The viscosity of the ferrofluids basically remains unchanged when shear rate is above 50 s−1, with increasing magnetic field strength; however, it first increases and then levels off when the rate is under 10 s−1, revealing that the shear rate and magnetic field strength together affect viscosity. The viscosity and its alteration in Zn-ferrite/PFPE oil-based ferrofluids could be deduced through our work, which will be greatly significant in basic theoretical research and in various applications.

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Magnetic investigation of iron-nitride-based magnetic fluid

Cited by 6 publications

References 9 publications

Nitrogen-Doped Porous Carbon Networks with Active Fe–N_x Sites to Enhance Catalytic Conversion of Polysulfides in Lithium–Sulfur Batteries

Nitrogen-Doped Porous Carbon Networks with Active Fe–N_x Sites to Enhance Catalytic Conversion of Polysulfides in Lithium–Sulfur Batteries

Ferrofluids: Synthetic Strategies, Stabilization, Physicochemical Features, Characterization, and Applications

Investigation of the Rheological Properties of Zn-Ferrite/Perfluoropolyether Oil-Based Ferrofluids

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Magnetic investigation of iron-nitride-based magnetic fluid

Cited by 6 publications

References 9 publications

Nitrogen-Doped Porous Carbon Networks with Active Fe–Nx Sites to Enhance Catalytic Conversion of Polysulfides in Lithium–Sulfur Batteries

Nitrogen-Doped Porous Carbon Networks with Active Fe–Nx Sites to Enhance Catalytic Conversion of Polysulfides in Lithium–Sulfur Batteries

Ferrofluids: Synthetic Strategies, Stabilization, Physicochemical Features, Characterization, and Applications

Investigation of the Rheological Properties of Zn-Ferrite/Perfluoropolyether Oil-Based Ferrofluids

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Nitrogen-Doped Porous Carbon Networks with Active Fe–N_x Sites to Enhance Catalytic Conversion of Polysulfides in Lithium–Sulfur Batteries

Nitrogen-Doped Porous Carbon Networks with Active Fe–N_x Sites to Enhance Catalytic Conversion of Polysulfides in Lithium–Sulfur Batteries