scholarly journals Effect of coverage on the magnetic properties of -COOH, -SH, and -NH2 ligand-protected cobalt nanoparticles

Nanoscale ◽  
2021 ◽  
Author(s):  
Barbara Farkas ◽  
Nora Henriette De Leeuw
Keyword(s):  
Magnetic Properties ◽  
Magnetic Nanoparticles ◽  
Cobalt Nanoparticles ◽  
Magnetic Behaviour

Implementation of magnetic nanoparticles in biomedicine requires their passivation, which often comes at a cost of diminished magnetic properties. For the design of nano-agents with targeted magnetic behaviour, it is...

scholarly journals A Perspective on Modelling Metallic Magnetic Nanoparticles in Biomedicine: From Monometals to Nanoalloys and Ligand-Protected Particles

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3611
Author(s):  
Barbara Farkaš ◽  
Nora H. de de Leeuw
Keyword(s):  
Magnetic Nanoparticles ◽  
Biomedical Applications ◽  
Magnetic Nanoparticle ◽  
Cobalt Nanoparticles ◽  
Magnetic Behaviour ◽  
Resonance Imaging ◽  
Magnetic Nanoparticle Hyperthermia ◽  
Magnetic Resonance Imaging Mri ◽  
Simulation Systems

The focus of this review is on the physical and magnetic properties that are related to the efficiency of monometallic magnetic nanoparticles used in biomedical applications, such as magnetic resonance imaging (MRI) or magnetic nanoparticle hyperthermia, and how to model these by theoretical methods, where the discussion is based on the example of cobalt nanoparticles. Different simulation systems (cluster, extended slab, and nanoparticle models) are critically appraised for their efficacy in the determination of reactivity, magnetic behaviour, and ligand-induced modifications of relevant properties. Simulations of the effects of nanoscale alloying with other metallic phases are also briefly reviewed.

Sonofragmentation Synthesis of Composition-Controlled Iron-Cobalt Nanoparticles with Enhanced Magnetic Properties

2021 ◽  
Vol 10 (1) ◽  
pp. 20210045
Author(s):  
Brajalal Sinha ◽  
Rubayet Tanveer ◽  
Palash Kumar Sarker ◽  
Md Nazrul Islam
Keyword(s):  
Magnetic Properties ◽  
Cobalt Nanoparticles ◽  
Iron Cobalt

scholarly journals Wet-spinning of magneto-responsive helical chitosan microfibers

2020 ◽  
Vol 11 ◽  
pp. 991-999
Author(s):  
Dorothea Brüggemann ◽  
Johanna Michel ◽  
Naiana Suter ◽  
Matheus Grande de Aguiar ◽  
Michael Maas
Keyword(s):  
Tissue Engineering ◽  
Magnetic Properties ◽  
Magnetic Nanoparticles ◽  
Mechanical Energy ◽  
Accessible Surface Area ◽  
Wet Spinning ◽  
Helical Structures ◽  
Structural Reinforcement ◽  
Electron Microscopy Analysis ◽  
Accessible Surface

Helical structures can be found in nature at various length scales ranging from the molecular level to the macroscale. Due to their ability to store mechanical energy and to optimize the accessible surface area, helical shapes contribute particularly to motion-driven processes and structural reinforcement. Due to these special features, helical fibers have become highly attractive for biotechnological and tissue engineering applications. However, there are only a few methods available for the production of biocompatible helical microfibers. Given that, we present here a simple technique for the fabrication of helical chitosan microfibers with embedded magnetic nanoparticles. Composite fibers were prepared by wet-spinning and coagulation in an ethanol bath. Thereby, no toxic components were introduced into the wet-spun chitosan fibers. After drying, the helical fibers had a diameter of approximately 130 µm. Scanning electron microscopy analysis of wet-spun helices revealed that the magnetic nanoparticles agglomerated into clusters inside the fiber matrix. The helical constructs exhibited a diameter of approximately 500 µm with one to two windings per millimeter. Due to their ferromagnetic properties they are easily attracted to a permanent magnet. The results from the tensile testing show that the helical chitosan microfibers exhibited an average Young’s modulus of 14 MPa. By taking advantage of the magnetic properties of the feedstock solution, the production of the helical fibers could be automated. The fabrication of the helical fibers was achieved by utilizing the magnetic properties of the feedstock solution and winding the emerging fiber around a rotating magnetic collector needle upon coagulation. In summary, our helical chitosan microfibers are very attractive for future use in magnetic tissue engineering or for the development of biocompatible actuator systems.

Studies of metal halides. Magnetic properties of some molybdenum(III) binuclear complex halides

1969 ◽  
Vol 22 (1) ◽  
pp. 121 ◽  
Author(s):  
IE Grey ◽  
PW Smith
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Binuclear Complex ◽  
Magnetic Behaviour ◽  
Metal Halides ◽  
Metal Interaction ◽  
Metal Metal ◽  
Halide Complexes

The variation of magnetic susceptibility with temperature for a number of binuclear halide complexes of molybdenum of formula A3IMo2X9 (A = Cs, Et4N, Et3NH; X = Cl, Br) has been studied over the range 90-400�K. The magnetic behaviour is consistent with that expected for magnetically isolated exchange-coupled pairs of molybdenum atoms. The coupling is interpreted as occurring mainly by direct metal-metal interaction rather than superexchange.

Effect of aluminum doped iron oxide nanoparticles on magnetic properties of the polyacrylonitrile nanofibers

2017 ◽  
Vol 37 (2) ◽  
pp. 135-141
Author(s):  
Armin Ourang ◽  
Soheil Pilehvar ◽  
Mehrzad Mortezaei ◽  
Roya Damircheli
Keyword(s):  
Magnetic Properties ◽  
Iron Oxide ◽  
Magnetic Nanoparticles ◽  
Iron Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Negative Interaction ◽  
Magnetic Nanofibers

Abstract In this work, polyacrylonitrile (PAN) was electrospun with and without magnetic nanoparticles (aluminum doped iron oxide) and was turned into magnetic nanofibers. The results showed that nanofibers diameter decreased from 700 nm to 300 nm by adding nanoparticles. Furthermore, pure PAN nanofibers were indicated to have low magnetic ability due to polar bonds that exist in their acrylonitrile groups. Obviously by adding only 4 wt% of the nanoparticles to PAN nanofibers, magnetic ability soared by more than 10 times, but at a higher percentage, it was shown to change just a little due to negative interaction among nanoparticles. This event relates to antiferromagnetically coupling of nanoparticles due to incomplete dispersion at higher percentage.

Preparation and magnetic properties of cobalt nanoparticles with dendrimers as templates

2010 ◽  
Vol 121 (1-2) ◽  
pp. 342-348 ◽  
Author(s):  
Hui-Xia Wu ◽  
Cui-Xia Zhang ◽  
Lei Jin ◽  
Hong Yang ◽  
Shi-Ping Yang
Keyword(s):  
Magnetic Properties ◽  
Cobalt Nanoparticles

scholarly journals The magnetic mechanical analysis of manganese steel

1921 ◽  
Vol 98 (692) ◽  
pp. 297-302 ◽  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Magnetic Properties ◽  
Chemical Analysis ◽  
Cold Water ◽  
Mechanical Analysis ◽  
Magnetic Behaviour ◽  
Manganese Steel

One of the most interesting alloys for the study of its magnetic properties is manganese steel. The following paper is an attempt to correlate some of the magnetic and mechanical properties of manganese steel, in the hope that as such data are circulated it will eventually be possible to interpret from the magnetic behaviour of steel what the mechanical properties will be. Six manganese steel rods supplied by one of the authors were drawn from the same source, 76 cm. long and 0·95 cm. in diameter, and used “as drawn.” These rods were marked 1, 2, 3, 4, 5, and 6 respectively. The chemical analysis was made on rod No. 4 and showed:— C................................1.25 per cent. Si................................ 0.43 „ Mn...............................12.20 „ The record for the heat treatment was as follows:—“ All six bars were treated at 1000° C. (five minutes), and then water-quenched in ordinary cold water. Nos. 1, 5 and 6 were then enclosed in an iron pipe welded over at the ends, and annealed. The time for cooling from 550° C. to 450° C. was about eight hours. As this treatment did not make the bars sufficiently magnetic they were again annealed at 500° C. (530° C.—475° C.) for sixty hours."

Chemical synthesis of Nd2Fe14B hard phase magnetic nanoparticles with an enhanced coercivity value: effect of CaH2 amount on the magnetic properties

2016 ◽  
Vol 40 (12) ◽  
pp. 10181-10186 ◽  
Author(s):  
Ji Hun Jeong ◽  
Hao Xuan Ma ◽  
Doyun Kim ◽  
Chang Woo Kim ◽  
In Ho Kim ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Nanoparticles ◽  
Chemical Synthesis ◽  
Diffusion Process ◽  
Hard Phase ◽  
Synthesis Route ◽  
Value Effect ◽  
Chemical Synthesis Route ◽  
And Diffusion

Nd2Fe14B hard phase magnetic nanoparticles were successfully synthesized using a chemical synthesis route followed by a reduction and diffusion process without consuming a large amount of energy.

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