scholarly journals Magnetite Nanoparticles Prepared By Spark Erosion

2016 ◽  
Vol 53 (4) ◽  
pp. 30-35 ◽  
Author(s):  
M. Maiorov ◽  
E. Blums ◽  
G. Kronkalns ◽  
A. Krumina ◽  
M. Lubane
Keyword(s):  
Magnetic Nanoparticles ◽  
Electric Discharge ◽  
Magnetite Nanoparticles ◽  
High Frequency ◽  
Distilled Water ◽  
Iron Particles ◽  
Spark Erosion ◽  
Co Precipitation

Abstract In the present research, we study a possibility of using the electric spark erosion method as an alternative to the method of chemical co-precipitation for preparation of magnetic nanoparticles. Initiation of high frequency electric discharge between coarse iron particles under a layer of distilled water allows obtaining pure magnetite nanoparticles.

Blocking Temperature of Magnetite Nanoparticles Fe3O4 Encapsulated Silicon Dioxide SiO2

2020 ◽  
Vol 855 ◽  
pp. 172-176 ◽  
Author(s):  
Togar Saragi ◽  
Hotmas D. Sinaga ◽  
Feni Rahmi ◽  
Gustiani A. Pramesti ◽  
Adi Sugiarto ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Silicon Dioxide ◽  
Temperature Dependence ◽  
Magnetite Nanoparticles ◽  
Quantum Interference ◽  
Blocking Temperature ◽  
Precipitation Method ◽  
Magnetic Characteristics ◽  
Superconducting Quantum Interference Device ◽  
Co Precipitation

One of the important characteristics of magnetic materials is the measurement of magnetic characteristics through Superconducting Quantum Interference Device (SQUID) especially magnetization temperature dependence M(T)ZFC and MTFC measurement. In this work, we reported magnetization temperature dependence measurements of magnetite nanoparticles without SiO2 encapsulation (Fe3O4) and magnetite nanoparticles with SiO2 encapsulation (Fe3O4.SiO2) at the application of magnetic fields of 100 Oe. The nanoparticles magnetite was synthesized by co-precipitation method. It was calculated that the blocking temperature of magnetite nanoparticles Fe3O4 without and with SiO2 encapsulation is 118.38 K and 209.03 K, respectively. The blocking temperatures of magnetic nanoparticles increase by SiO2 encapsulation.

Fe3O4@SiO2@polyionene/Br3− core–shell–shell magnetic nanoparticles: a novel catalyst for the synthesis of imidazole derivatives under solvent-free conditions

2016 ◽  
Vol 40 (5) ◽  
pp. 4575-4587 ◽  
Author(s):  
Elham Dezfoolinezhad ◽  
Keivan Ghodrati ◽  
Rashid Badri
Keyword(s):  
Magnetic Nanoparticles ◽  
Magnetite Nanoparticles ◽  
Solvent Free ◽  
Precipitation Method ◽  
Core Shell ◽  
Imidazole Derivatives ◽  
Solvent Free Conditions ◽  
Co Precipitation ◽  
Novel Catalyst

New Fe3O4@SiO2@polyionene/Br3− core–shell–shell magnetite nanoparticles were prepared using a co-precipitation method and were used in the syntheses of imidazole derivatives under solvent-free conditions.

Facile co-precipitation synthesis of shape-controlled magnetite nanoparticles

2014 ◽  
Vol 40 (1) ◽  
pp. 1519-1524 ◽  
Author(s):  
Lazhen Shen ◽  
Yongsheng Qiao ◽  
Yong Guo ◽  
Shuangming Meng ◽  
Guochen Yang ◽  
...  
Keyword(s):  
Magnetite Nanoparticles ◽  
Shape Controlled ◽  
Precipitation Synthesis ◽  
Co Precipitation

The High-frequency Electric Discharge at Low Pressures

1928 ◽  
Vol 24 (2) ◽  
pp. 259-267
Author(s):  
James Taylor ◽  
Wilfrid Taylor
Keyword(s):  
Electric Discharge ◽  
High Frequency ◽  
Electrical Discharges ◽  
X Ray ◽  
High Frequency Oscillations ◽  
Low Pressures

Experiments have been conducted by Gutton, and later by Kirchner, and by Gill and Donaldson upon electrical discharges through gases under the influence of high-frequency oscillations of the order of 107 cycles per second. It was found that the peak voltages required to maintain bright luminous discharges were of the order of 100 volts even when the pressure was as low as that in a soft X-ray tube. The present paper deals with some further studies of these phenomena.

scholarly journals Empirical Expression for AC Magnetization Harmonics of Magnetic Nanoparticles under High-Frequency Excitation Field for Thermometry

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2506
Author(s):  
Zhongzhou Du ◽  
Dandan Wang ◽  
Yi Sun ◽  
Yuki Noguchi ◽  
Shi Bai ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
High Frequency ◽  
Planck Equation ◽  
Magnetization Dynamics ◽  
Excitation Field ◽  
Fokker Planck Equation ◽  
High Frequency Excitation ◽  
Frequency Excitation ◽  
Ac Magnetization ◽  
Fokker Planck

The Fokker–Planck equation accurately describes AC magnetization dynamics of magnetic nanoparticles (MNPs). However, the model for describing AC magnetization dynamics of MNPs based on Fokker-Planck equation is very complicated and the numerical calculation of Fokker-Planck function is time consuming. In the stable stage of AC magnetization response, there are differences in the harmonic phase and amplitude between the stable magnetization response of MNPs described by Langevin and Fokker–Planck equation. Therefore, we proposed an empirical model for AC magnetization harmonics to compensate the attenuation of harmonics amplitude induced by a high frequency excitation field. Simulation and experimental results show that the proposed model accurately describes the AC M–H curve. Moreover, we propose a harmonic amplitude–temperature model of a magnetic nanoparticle thermometer (MNPT) in a high-frequency excitation field. The simulation results show that the temperature error is less than 0.008 K in the temperature range 310–320 K. The proposed empirical model is expected to help improve MNPT performance.

scholarly journals Magnetite-Silica Core/Shell Nanostructures: From Surface Functionalization towards Biomedical Applications—A Review

2021 ◽  
Vol 11 (22) ◽  
pp. 11075
Author(s):  
Angela Spoială ◽  
Cornelia-Ioana Ilie ◽  
Luminița Narcisa Crăciun ◽  
Denisa Ficai ◽  
Anton Ficai ◽  
...  
Keyword(s):  
Magnetite Nanoparticles ◽  
Biomedical Applications ◽  
Sol Gel ◽  
Magnetic Nanomaterials ◽  
Core Shell ◽  
Synthesis Methods ◽  
Shell Nanostructures ◽  
Silica Core ◽  
Magnetic Resonance Imaging Mri ◽  
Co Precipitation

The interconnection of nanotechnology and medicine could lead to improved materials, offering a better quality of life and new opportunities for biomedical applications, moving from research to clinical applications. Magnetite nanoparticles are interesting magnetic nanomaterials because of the property-depending methods chosen for their synthesis. Magnetite nanoparticles can be coated with various materials, resulting in “core/shell” magnetic structures with tunable properties. To synthesize promising materials with promising implications for biomedical applications, the researchers functionalized magnetite nanoparticles with silica and, thanks to the presence of silanol groups, the functionality, biocompatibility, and hydrophilicity were improved. This review highlights the most important synthesis methods for silica-coated with magnetite nanoparticles. From the presented methods, the most used was the Stöber method; there are also other syntheses presented in the review, such as co-precipitation, sol-gel, thermal decomposition, and the hydrothermal method. The second part of the review presents the main applications of magnetite-silica core/shell nanostructures. Magnetite-silica core/shell nanostructures have promising biomedical applications in magnetic resonance imaging (MRI) as a contrast agent, hyperthermia, drug delivery systems, and selective cancer therapy but also in developing magnetic micro devices.

scholarly journals Removal of Chromium (VI) cation metal using Poly (N-vinyl-2-pyrrolidone)/Magnetite nanocomposite from aqueous media

2017 ◽  
Vol 13 (10) ◽  
pp. 5886-5891
Author(s):  
Padmalaya G ◽  
Sreeja BS ◽  
Radha S ◽  
Raamdheep G ◽  
Saranya J
Keyword(s):  
Magnetite Nanoparticles ◽  
Infrared Absorption Spectrum ◽  
Aqueous Media ◽  
Polyvinyl Pyrrolidone ◽  
Human Society ◽  
Promising Alternative ◽  
Chromium Vi ◽  
Ir Studies ◽  
Vis Spectroscopy ◽  
Co Precipitation

Groundwater contamination with heavy metals is considered as serious environmental hazard that affect the human society. Nano adsorbents incorporating magnetite nanoparticles provides promising alternative to facilitate removal of heavy metal ions from wastewater. The present work focuses on removal of chromium (VI) cationic metals from aqueous media using Polyvinyl Pyrrolidone (PVP)/Magnetite (Fe3O4) Nanocomposite (MNC). Magnetite nanoparticles are synthesized using chemical co-precipitation and grafted using polyvinyl pyrrolidone to form a magnetite nanocomposite. MNC were characterized with X-ray diffraction (XRD) and Infrared absorption spectrum (FT-IR) studies to affirm the formation and presence of polymeric functional groups of PVP/Magnetite nanocomposite. Batch experiments are carried out at exclusive concentration intervals to study about the adsorption efficiency of MNC on chromium (VI) cationic metal using U-Vis spectroscopy. The results obtained through adsorption studies shows the synthesized PVP/Magnetite nanocomposites has a removal efficiency of 94%.

scholarly journals Role of mexidol (2-ethyl-6-methyl-3-hydroxypyridine succinate) in the obtaining of stabilized magnetite nanoparticles for biomedical application

2015 ◽  
Vol 61 (3) ◽  
pp. 384-388 ◽  
Author(s):  
Ye.M. Vazhnichaya ◽  
Ye.V. Mokliak ◽  
Yu.A. Kurapov ◽  
A.A. Zabozlaev
Keyword(s):  
Liquid Phase ◽  
Magnetite Nanoparticles ◽  
Malignant Tumors ◽  
Biomedical Application ◽  
Iron Concentration ◽  
Atomic Emission ◽  
Electron Beam Evaporation ◽  
Correlation Spectroscopy ◽  
Emission Spectrometry ◽  
Distilled Water

Magnetite nanoparticles (NPs) are studied as agents for magnetic resonance imaging, hyperthermia of malignant tumors, targeted drug delivery as well as anti-anemic action. One of the main problems of such NPs is their aggregation that requires creation of methods for magnetite NPs stabilization during preparation of liquid medicinal forms on their basis. The present work is devoted to the possibility of mexidol (2-ethyl-6-methyl-3-hydroxypyridine succinate) use for solubilization of magnetite NPs in hydrophilic medium. For this purpose, the condensate produced by electron-beam evaporation and condensation, with magnetite particles of size 5-8 nm deposited into the crystals of sodium chloride were used in conjunction with substance of mexidol (2-ethyl-6-methyl-3-hydroxypyridine succinate), and low molecular weight polyvinylpyrrolidone (PVP). The NP condensate was dispersed in distilled water or PVP or mexidol solutions. NPs size distribution in the liquid phase of the systems was determined by photon correlation spectroscopy, iron (Fe) concentration was evaluated by atomic emission spectrometry. It is shown that in the dispersion prepared in distilled water, the major amount of NPs was of 13-120 nm in size, in mexidol solution - 270-1700 nm, in PVP solution - 30-900 nm. In the fluid containing magnetite NPs together with mexidol and PVP, the main fraction (99.9%) was characterized by the NPs size of 14-75 nm with maximum of 25 nm. This system had the highest iron concentration: it was similar to that in the sample with mexidol solution and 6.6-7.3 times higher than the concentration in the samples with distilled water or PVP. Thus, in the preparation of aqueous dispersions based on magnetite NPs condensate, mexidol provides a transition of Fe to the liquid phase in amount necessary to achieve its biological activity, and PVP stabilizes such modified NPs.

Sign in / Sign up

Export Citation Format

Share Document