Journal articles: 'Magnetite Heat treatment'

1

Singh, Rajendra Kumar, A. Perumal, Govind P. Kothiyal, and A. Srinivasan. "Evolution of Magnetism in CaO-SiO₂-P₂O₅-Na₂O-Fe₂O₃ Bioglass Ceramics." Materials Science Forum 587-588 (June 2008): 171–74. http://dx.doi.org/10.4028/www.scientific.net/msf.587-588.171.

Full text

Abstract:

We report the evolution of magnetism in bioglass ceramics 41CaO.(52-x)SiO2.4P2O5. xFe2O3.3Na2O (2 ≤ x ≤ 10 mole % Fe2O3) prepared by melt quenching technique followed by heat treatment at 1050 oC. The structural investigation revealed the presence of magnetite phase in the heat treated samples with x ≥ 2 mole % Fe2O3. Room temperature magnetic measurements showed a very weak ferrimagnetic behaviour for the sample with x = 2 mole % of Fe2O3. Samples with x > 2 mole % of Fe2O3 exhibited magnetic behavior similar to soft magnetic materials with low coercivity. The evolution of magnetic properties in these samples as a function of Fe2O3 molar concentration is correlated with the amount of magnetite phase present in them.

APA, Harvard, Vancouver, ISO, and other styles

2

Kalska-Szostko, Beata, Urszula Wykowska, Dariusz Satula, and Per Nordblad. "Thermal treatment of magnetite nanoparticles." Beilstein Journal of Nanotechnology 6 (June 23, 2015): 1385–96. http://dx.doi.org/10.3762/bjnano.6.143.

Full text

Abstract:

This paper presents the results of a thermal treatment process for magnetite nanoparticles in the temperature range of 50–500 °C. The tested magnetite nanoparticles were synthesized using three different methods that resulted in nanoparticles with different surface characteristics and crystallinity, which in turn, was reflected in their thermal durability. The particles were obtained by coprecipitation from Fe chlorides and decomposition of an Fe(acac)3 complex with and without a core–shell structure. Three types of ferrite nanoparticles were produced and their thermal stability properties were compared. In this study, two sets of unmodified magnetite nanoparticles were used where crystallinity was as determinant of the series. For the third type of particles, a Ag shell was added. By comparing the coated and uncoated particles, the influence of the metallic layer on the thermal stability of the nanoparticles was tested. Before and after heat treatment, the nanoparticles were examined using transmission electron microscopy, IR spectroscopy, differential scanning calorimetry, X-ray diffraction and Mössbauer spectroscopy. Based on the obtained results, it was observed that the fabrication methods determine, to some extent, the sensitivity of the nanoparticles to external factors.

APA, Harvard, Vancouver, ISO, and other styles

3

Wang, Yao Yao, Bin Li, and Yong Ya Wang. "Characterization of Fe₂O₃-CaO-SiO₂ Glass Ceramics Prepared by Sol-Gel." Applied Mechanics and Materials 624 (August 2014): 114–18. http://dx.doi.org/10.4028/www.scientific.net/amm.624.114.

Full text

Abstract:

Ferromagnetic glass ceramics with magnetism and biological activity could be used for magnetic induction hyperthermia. In this study Fe2O3-CaO-SiO2glass-ceramics were prepared by sol-gel method. The sample was characterized by X-ray diffraction (XRD) and differential thermal analysis (DTA). The results showed that the major phases of the sample are wollastonite and magnetite and the crystallization activation energy of sample is 189.3KJ/mol, which would provide a theoretical basis for the establishment of the optimum process conditions of heat treatment technology.

APA, Harvard, Vancouver, ISO, and other styles

4

Seo, Gyu Tae, Jin Tae Kim, Sung Su Kim, and Jutamas Kaewsuk. "Synthesis of Magnetite Nano-Particles and Powder Activated Carbon as a Novel Material for Water Treatment." Materials Science Forum 620-622 (April 2009): 145–48. http://dx.doi.org/10.4028/www.scientific.net/msf.620-622.145.

Full text

Abstract:

The objective of this study is to develop a novel powder activated carbon (PAC) by surface modification with magnetite nano-particles for enhanced removal of NOM in water. The PAC used for experiment was two types, SAC (wood-based) and MAC (coal-based). First the PAC was treated by heat at 650 or 900 °C for 1hr under N2. And then the PAC surface was synthesized with magnetite nano-particles at the same condition. Adsorption tests of NOM were carried out to identify functional characteristics of the surface modified. Despite reduced surface area, adsorption capacity of the surface modified PAC was comparable to the virgin one. However much increased adsorption capacity was obtained by heat treatment of the PACs. SEC and SUVA254 results showed no specific selectivity in removal of NOM by the modification of PAC surface characteristics. Enhanced oxidation of the NOM was also observed by the magnetite nano-particle synthetic PACs in contact with ozone. Conclusively the surface modification of the PAC has high potential as a novel adsorption material for advanced water treatment.

APA, Harvard, Vancouver, ISO, and other styles

5

Ruskin, Ethel Ibinabo, Paritosh Perry Coomar, Prabaha Sikder, and Sarit B. Bhaduri. "Magnetic Calcium Phosphate Cement for Hyperthermia Treatment of Bone Tumors." Materials 13, no. 16 (August 8, 2020): 3501. http://dx.doi.org/10.3390/ma13163501.

Full text

Abstract:

This article reports, for the first time, the ‘proof-of-concept’ results on magnetic monetite (CaHPO4)-based calcium phosphate cements (CPCs) compositions developed for the hyperthermia treatment of bone tumors. Hyperthermia involves the heating of a tumor within a temperature range of 40–45 °C, inducing apoptosis in the tumor cells. This process holds promising potential in the field of cancer treatment and has been proven to be more effective than conventional therapeutics. Hence, we aimed to develop cement compositions that are capable of the hyperthermia treatment of bone tumors. To achieve that central goal, we incorporated iron oxide (Fe3O4), a ferromagnetic material, into monetite and hypothesized that, upon the application of a magnetic field, magnetite will generate heat and ablate the tumor cells near the implantation site. The results confirmed that an optimized content of magnetite incorporation in monetite can generate heat in the range of 40–45 °C upon the application of a magnetic field. Furthermore, the compositions were bioactive and cytocompatible with an osteoblastic cell line.

APA, Harvard, Vancouver, ISO, and other styles

6

Włodarczyk, Agnieszka, Szymon Gorgoń, Adrian Radoń, and Karolina Bajdak-Rusinek. "Magnetite Nanoparticles in Magnetic Hyperthermia and Cancer Therapies: Challenges and Perspectives." Nanomaterials 12, no. 11 (May 25, 2022): 1807. http://dx.doi.org/10.3390/nano12111807.

Full text

Abstract:

Until now, strategies used to treat cancer are imperfect, and this generates the need to search for better and safer solutions. The biggest issue is the lack of selective interaction with neoplastic cells, which is associated with occurrence of side effects and significantly reduces the effectiveness of therapies. The use of nanoparticles in cancer can counteract these problems. One of the most promising nanoparticles is magnetite. Implementation of this nanoparticle can improve various treatment methods such as hyperthermia, targeted drug delivery, cancer genotherapy, and protein therapy. In the first case, its feature makes magnetite useful in magnetic hyperthermia. Interaction of magnetite with the altered magnetic field generates heat. This process results in raised temperature only in a desired part of a patient body. In other therapies, magnetite-based nanoparticles could serve as a carrier for various types of therapeutic load. The magnetic field would direct the drug-related magnetite nanoparticles to the pathological site. Therefore, this material can be used in protein and gene therapy or drug delivery. Since the magnetite nanoparticle can be used in various types of cancer treatment, they are extensively studied. Herein, we summarize the latest finding on the applicability of the magnetite nanoparticles, also addressing the most critical problems faced by smart nanomedicine in oncological therapies.

APA, Harvard, Vancouver, ISO, and other styles

7

Liu, Boyang, Dechang Jia, Haibo Feng, Qingchang Meng, and Yingfeng Shao. "Synthesis and formation mechanism of hollow carbon spheres encapsulating magnetite nanocrystals." Journal of Materials Research 23, no. 7 (July 2008): 1980–86. http://dx.doi.org/10.1557/jmr.2008.0244.

Full text

Abstract:

Hollow carbon spheres encapsulating magnetite nanocrystals were obtained in high-pressure argon at 600 °C followed by hydrolysis of Fe(NH3)2Cl2 in the hollow interiors at room temperature and heat treatment in argon at 450 °C for 2 h. The structure, morphology, and properties of the products were characterized by x-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, and vibrating sample magnetometry. The hollow carbon spheres have diameters of 1–10 μm and wall thicknesses of hundreds of nanometers; the wt% of magnetite nanocrystals in them is ∼13.2%. Equiaxed magnetite nanocrystals range in size from 15 to 90 nm, while acicular magnetite nanocrystals have diameters of ∼20 nm and lengths of 120–450 nm. The saturation magnetization value of the hollow carbon spheres encapsulating magnetite nanocrystals is 4.29 emu/g.

APA, Harvard, Vancouver, ISO, and other styles

8

Nazlan, Rodziah, Nurul Hidayah Ghazali, Nur Asyikin Ahmad Nazri, Azaima Razali, Ros Azlinawati Ramli, and Mei Lian Yuen. "Structural and Magnetic Characteristics Evaluation of Iron Oxide Extracted from Printer Toner Wastes." Materials Science Forum 1056 (March 14, 2022): 99–104. http://dx.doi.org/10.4028/p-i4liyl.

Full text

Abstract:

The need to recycle and develop valuable materials from waste, and use them in various applications have become increasingly important in recent decades. Printer toner waste is one of the most polluting electronic waste due to the toxic nature of the material content in it. Despite the toxicity of the material in the toner powder, it contains iron oxide that can be extracted and recycled to make a beneficial material. Therefore, this study aims to investigate a facile and effective method to extract iron oxide from printer toner waste powder. Magnetic separation and oxidation processes were used as a method for extraction and phase conversion. The structural transformation was investigated using X-ray diffraction, microstructural observation using scanning electron microscope whereas static magnetic characteristics were investigates using vibrating sample magnetometer. The results from XRD spectra show that printer toner wastes that have been subjected to magnetic separation process and chemical treatment, even without any heat treatment process, have produced a single phase magnetite. Through the process of heat treatment on the sample, phase transformation from magnetite to hematite occurs, in which a single phase of hematite is obtained at a temperature of 1400 °C. The saturation magnetization of the sample also showed a reduction where the sample before undergoing the heat treatment process had a saturated magnetization value of 18.81 emu/g. Meanwhile, after heat treatment, the saturation magnetization value decreased to 0.42 emu/g. These results are in line with the phase transformation shown where magnetite has high ferrimagnetic characteristics, whereas hematite is basically antiferromagnetic at room temperature. However, the saturation magnetization that has been obtained in hematite shows a little difference to that of commercially sold hematite. This proves that iron oxide extracted from printer toner waste has a high potential as an alternative to existing commercial iron oxide in producing high performance magnetic materials.

APA, Harvard, Vancouver, ISO, and other styles

9

Cabrera, Flávio C., Antonio F. A. A. Melo, João C. P. de Souza, Aldo E. Job, and Frank N. Crespilho. "A flexible lab-on-a-chip for the synthesis and magnetic separation of magnetite decorated with gold nanoparticles." Lab on a Chip 15, no. 8 (2015): 1835–41. http://dx.doi.org/10.1039/c4lc01483a.

Full text

Abstract:

The preparation of controlled amounts of magnetite nanoparticles decorated with gold nanoparticles without organic solvents, surfactants, or heat treatment is presented. For this, natural-rubber-based microfluidic device (NRMD) was used as a flexible lab-on-a-chip.

APA, Harvard, Vancouver, ISO, and other styles

10

Wence, Xu, Chen Weili, Jia Xiaolin, and Zhang Xuefeng. "Effect of magnetic-field heat treatment on directional growth of magnetite in glass ceramics." Materials Research Express 6, no. 7 (April 3, 2019): 075204. http://dx.doi.org/10.1088/2053-1591/ab11ac.

Full text

APA, Harvard, Vancouver, ISO, and other styles

11

Veres, Tamás, Constantinos Voniatis, Kristóf Molnár, Dániel Nesztor, Daniella Fehér, Andrea Ferencz, Iván Gresits, et al. "An Implantable Magneto-Responsive Poly(aspartamide) Based Electrospun Scaffold for Hyperthermia Treatment." Nanomaterials 12, no. 9 (April 26, 2022): 1476. http://dx.doi.org/10.3390/nano12091476.

Full text

Abstract:

When exposed to an alternating magnetic field, superparamagnetic nanoparticles can elicit the required hyperthermic effect while also being excellent magnetic resonance imaging (MRI) contrast agents. Their main drawback is that they diffuse out of the area of interest in one or two days, thus preventing a continuous application during the typical several-cycle multi-week treatment. To solve this issue, our aim was to synthesise an implantable, biodegradable membrane infused with magnetite that enabled long-term treatment while having adequate MRI contrast and hyperthermic capabilities. To immobilise the nanoparticles inside the scaffold, they were synthesised inside hydrogel fibres. First, polysuccinimide (PSI) fibres were produced by electrospinning and crosslinked, and then, magnetitc iron oxide nanoparticles (MIONs) were synthesised inside and in-between the fibres of the hydrogel membranes with the well-known co-precipitation method. The attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR) investigation proved the success of the chemical synthesis and the presence of iron oxide, and the superconducting quantum interference device (SQUID) study revealed their superparamagnetic property. The magnetic hyperthermia efficiency of the samples was significant. The given alternating current (AC) magnetic field could induce a temperature rise of 5 °C (from 37 °C to 42 °C) in less than 2 min even for five quick heat-cool cycles or for five consecutive days without considerable heat generation loss in the samples. Short-term (1 day and 7 day) biocompatibility, biodegradability and MRI contrast capability were investigated in vivo on Wistar rats. The results showed excellent MRI contrast and minimal acute inflammation.

APA, Harvard, Vancouver, ISO, and other styles

12

Bayat, Masoumeh, Heejae Yang, and Frank Ko. "Effect of iron oxide nanoparticle size on electromagnetic properties of composite nanofibers." Journal of Composite Materials 52, no. 13 (September 20, 2017): 1723–36. http://dx.doi.org/10.1177/0021998317732139.

Full text

Abstract:

Electrically conductive and magnetically permeable carbon nanofiber-based composites were developed using the electrospinning with subsequent heat treatment. The composite nanofiber contains a variable composition of magnetite nanoparticles with two different size regimes, ranging from superparamagnetic (10–20 nm) to ferromagnetic (20–30 nm). The composite nanofibers are then characterized using Scanning/Transmission Electron Microscopy, X-Ray Diffractometry, Raman Spectroscopy, four-point probe, and a Superconducting Quantum Interference Device. Electromagnetic Interference Shielding Effectiveness of pristine carbon nanofibers as well as electromagnetic composite nanofibers are examined in the X-band frequency region. Higher degree of graphitization, electrical conductivity, and magnetic strength are obtained for nanocomposites containing larger magnetite nanoparticles (20–30 nm). A transition from superpartamagnetic to ferromagnetic characteristics is observed during nanocomposite processing. Electromagnetic Interference Shielding Effectiveness of as high as 68 dB (in the working frequency of 10.4 GHz) is observed for composite nanofibers fabricated with larger magnetite nanoparticles carbonized at 900℃.

APA, Harvard, Vancouver, ISO, and other styles

13

Pérez Pérez, Leticia Mariana Carmen, Julian Hernández Torres, Luis Zamora Peredo, Leandro García González, Manuel García Hipólito, Ciro Falcony Guajardo, Pablo Eduardo Cardoso Avila, Oscar Velázquez Camilo, and Adriana Báez Rodríguez. "Obtaining Hematite Nanoflakes Substrates By Electrochemical Anodization of Iron Foil and Heat Treatment." ECS Transactions 106, no. 1 (January 31, 2022): 203–10. http://dx.doi.org/10.1149/10601.0203ecst.

Full text

Abstract:

Synthesizing nanostructure’s importance is due to the applications that these materials can offer. Electrochemical anodization is considered an easily accessible technique; variables control allows to obtain diverse morphologies (from nanopores to nanotubes). The main reaction is oxide – reduction, it produces a protective oxide layer to metals and promotes different morphologies. Anodized iron sheets were carried out, with a concentration of 1.2 M of NH4F in a solution of ethylene glycol and water. The anodization time (5, 10, 15, and 20 minutes) was varied to a constant potential of 30 Volts. The substrates were subjected to annealing of 450 °C for 2 hours to obtain the hematite phase, it was observed that the morphology changed to nanoflakes. With Raman spectroscopy and X-ray diffraction, phase mixing (hematite and magnetite) was determined. The bandgap of 2.15 eV was determined with diffuse reflectance

APA, Harvard, Vancouver, ISO, and other styles

14

Kobori, H., T. Asahi, Y. Yamasaki, A. Sugimura, T. Taniguchi, A. Ando, H. Kawanaka, Y. Naitoh, and T. Shimizu. "Spin‐dependent‐magnetoresistance control by regulation of heat treatment temperature for magnetite nano‐particle sinter." Annalen der Physik 521, no. 12 (December 23, 2009): 935–38. http://dx.doi.org/10.1002/andp.20095211225.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

Hou, Yong-shen. "Effect of Heat Treatment on Preparation of Ferrite Magnetite Hollow Beads by Self-Propagating Method." Journal of Physics: Conference Series 2174, no. 1 (January 1, 2022): 012022. http://dx.doi.org/10.1088/1742-6596/2174/1/012022.

Full text

Abstract:

Abstract The characterization results of hollow ceramic beads show that oxidant KClO3 had a great influence on the preparation of hollow ceramic beads. The morphology picture and XRD analysis showed that the surface of hollow beads without KClO3 was smooth, and the particle size analysis results show that the particle size was 10 ~ 50μm. Without KClO3, the average particle size is 28.08 μm; After adding KClO3, dense dendritic crystal structure was distributed on the surface of hollow beads, and the phase is mainly BaFe2O4, and the distribution range of hollow beads is 5 ~ 40 μm, and the average particle size is 16.02 μm° It could be inferred from the analysis that the quenching reaction is fully carried out after the addition of KClO3, resulting in a large amount of gas, reducing the volume of ceramic droplets and reducing the particle size of hollow beads.

APA, Harvard, Vancouver, ISO, and other styles

16

Kobori, H., T. Asahi, A. Yamasaki, A. Sugimura, T. Taniguchi, A. Ando, H. Kawanaka, Y. Naitoh, and T. Shimizu. "Electrical- and magneto-resistance control for magnetite nanoparticle sinter by regulation of heat treatment temperature." Journal of Magnetism and Magnetic Materials 323, no. 6 (March 2011): 686–90. http://dx.doi.org/10.1016/j.jmmm.2010.10.016.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Kobori, H., T. Asahi, Y. Yamasaki, A. Sugimura, T. Taniguchi, A. Ando, H. Kawanaka, Y. Naitoh, and T. Shimizu. "Spin-dependent-magnetoresistance control by regulation of heat treatment temperature for magnetite nano-particle sinter." Annalen der Physik 18, no. 12 (December 23, 2009): 935–38. http://dx.doi.org/10.1002/andp.200910385.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

Jimbow, Kowichi, Yasue Ishii-Osai, Shosuke Ito, Yasuaki Tamura, Akira Ito, Akihiro Yoneta, Takafumi Kamiya, et al. "Melanoma-Targeted Chemothermotherapy andIn SituPeptide Immunotherapy through HSP Production by Using Melanogenesis Substrate, NPrCAP, and Magnetite Nanoparticles." Journal of Skin Cancer 2013 (2013): 1–12. http://dx.doi.org/10.1155/2013/742925.

Full text

Abstract:

Exploitation of biological properties unique to cancer cells may provide a novel approach to overcome difficult challenges to the treatment of advanced melanoma. In order to develop melanoma-targeted chemothermoimmunotherapy, a melanogenesis substrate, N-propionyl-4-S-cysteaminylphenol (NPrCAP), sulfur-amine analogue of tyrosine, was conjugated with magnetite nanoparticles. NPrCAP was exploited from melanogenesis substrates, which are expected to be selectively incorporated into melanoma cells and produce highly reactive free radicals through reacting with tyrosinase, resulting in chemotherapeutic and immunotherapeutic effects by oxidative stress and apoptotic cell death. Magnetite nanoparticles were conjugated with NPrCAP to introduce thermotherapeutic and immunotherapeutic effects through nonapoptotic cell death and generation of heat shock protein (HSP) upon exposure to alternating magnetic field (AMF). During these therapeutic processes, NPrCAP was also expected to provide melanoma-targeted drug delivery system.

APA, Harvard, Vancouver, ISO, and other styles

19

Kis, A. C., Th Leventouri, and J. R. Thompson. "Magnetic and Structural Properties of Ferrimagnetic Bioceramics." Materials Science Forum 473-474 (January 2005): 117–22. http://dx.doi.org/10.4028/www.scientific.net/msf.473-474.117.

Full text

Abstract:

Structure and magnetic properties of ferrimagnetic bioceramics in the system {0.45(CaO, P2O5) ySiO2 xFe2O3 0.03Na2O}, x=0.05, 0.10, 0.15, 0.20, were studied by x-ray powder diffraction and magnetic measurements. Magnetite and calcium phosphate, crystallizing in the hexagonal and monoclinic crystal systems, are the major phases in the compounds. Phase development, crystal structure, and magnetic properties of the composites are determined by the specific starting composition of oxides and the heat-treatment temperature.

APA, Harvard, Vancouver, ISO, and other styles

20

Miyazaki, Toshiki, Jun Akaike, Masakazu Kawashita, and Hong Ngee Lim. "In vitro apatite mineralization and heat generation of magnetite-reduced graphene oxide nanocomposites for hyperthermia treatment." Materials Science and Engineering: C 99 (June 2019): 68–72. http://dx.doi.org/10.1016/j.msec.2019.01.091.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Yushchuk, S. I., V. V. Moklyak, and S. O. Yuryev. "Magnetic Hyperfine Structure of Epitaxial Films of Nickel Ferrite." Фізика і хімія твердого тіла 17, no. 3 (September 15, 2016): 381–85. http://dx.doi.org/10.15330/pcss.17.3.381-385.

Full text

Abstract:

Comparative NGR study of the parameters of the magnetic hyperfine structure of epitaxial films grown on single-crystal substrates of orientations of (100) and (111) by liquid phase epitaxy (LPE) and chemical transport reactions (CTR) is conducted. It is established that in the films obtained by the method of CTR, there is a significant number of ions of bivalent iron, which is in phase magnetite . After heat treatment of these films in air at T = 1273 K, the magnetite becomes the oxide. In the films of , grown by the LPE method the divalent iron was not detected. As shown by calculations, the vector direction of the magnetization of films obtained by the method of LPE, lies in the film plane regardless of the orientation (100) or (111) substrates. In films obtained by the CTR method, it forms with the substrate 41 - 450.

APA, Harvard, Vancouver, ISO, and other styles

22

Ahmed, Naveed, Asifa Tassaddiq, Rana Alabdan, Adnan, Umar Khan, Saima Noor, Syed Tauseef Mohyud-Din, and Ilyas Khan. "Applications of Nanofluids for the Thermal Enhancement in Radiative and Dissipative Flow over a Wedge." Applied Sciences 9, no. 10 (May 14, 2019): 1976. http://dx.doi.org/10.3390/app9101976.

Full text

Abstract:

The colloidal analysis for H2O and EG (Ethylene Glycol) by considering the influence of radiative heat flux and viscous dissipation is not performed so far. This study is performed to fill up this gap. Therefore, the flow of water and ethylene glycol functionalized magnetite nanoparticles over a moving wedge is examined. For thermal enhancement, two different magnetite nanoparticles, namely CoFe 2 O 4 (Cobalt ferrite) and Mn − ZnFe 2 O 4 ( Mn − Zn ferrite), diluted in the base fluids. Self-similar flow model of a nonlinear nature, containing the volume fraction of nanoparticles is obtained by using compatible similarity variables. For mathematical treatment of the model, the Runge-Kutta scheme is utilized, coupled with shooting techniques. The results for flow characteristics and significant physical parameters are graphically examined. A comprehensive comparative analysis has been made, which proved the reliability of the study.

APA, Harvard, Vancouver, ISO, and other styles

23

Simeonidis, Konstantinos, Efthimia Kaprara, Pilar Rivera-Gil, Ruixue Xu, Francisco J. Teran, Evgenios Kokkinos, Athanassios Mitropoulos, Nikolaos Maniotis, and Lluis Balcells. "Hydrotalcite-Embedded Magnetite Nanoparticles for Hyperthermia-Triggered Chemotherapy." Nanomaterials 11, no. 7 (July 9, 2021): 1796. http://dx.doi.org/10.3390/nano11071796.

Full text

Abstract:

A magnetic nanocomposite, consisting of Fe3O4 nanoparticles embedded into a Mg/Al layered double hydroxide (LDH) matrix, was developed for cancer multimodal therapy, based on the combination of local magnetic hyperthermia and thermally induced drug delivery. The synthesis procedure involves the sequential hydrolysis of iron salts (Fe2+, Fe3+) and Mg2+/Al3+ nitrates in a carbonate-rich mild alkaline environment followed by the loading of 5-fluorouracil, an anionic anticancer drug, in the interlayer LDH space. Magnetite nanoparticles with a diameter around 30 nm, dispersed in water, constitute the hyperthermia-active phase able to generate a specific loss of power of around 500 W/g-Fe in an alternating current (AC) magnetic field of 24 kA/m and 300 kHz as determined by AC magnetometry and calorimetric measurements. Heat transfer was found to trigger a very rapid release of drug which reached 80% of the loaded mass within 10 min exposure to the applied field. The potential of the Fe3O4/LDH nanocomposites as cancer treatment agents with minimum side-effects, owing to the exclusive presence of inorganic phases, was validated by cell internalization and toxicity assays.

APA, Harvard, Vancouver, ISO, and other styles

24

Morfin-Gutiérrez, A., H. Iván Meléndez-Ortiz, B. A. Puente-Urbina, and L. A. García-Cerda. "Synthesis of Poly(N-vinylcaprolactam)-Grafted Magnetite Nanocomposites for Magnetic Hyperthermia." Journal of Nanomaterials 2018 (October 17, 2018): 1–6. http://dx.doi.org/10.1155/2018/9562020.

Full text

Abstract:

In this study, the synthesis, characterization, and application of poly(N-vinylcaprolactam)-grafted magnetite nanocomposites for magnetic hyperthermia are reported. Superparamagnetic magnetite nanoparticles (MagNPs) with sizes in the range of 10–16 nm were synthesized by the coprecipitation method and then functionalized with vinyltrimethoxysilane (VTMS). MagNPs-VTMS coated with poly(N-vinylcaprolactam) (PNVCL) were prepared by free radical polymerization. The obtained materials were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), vibration sample magnetometry (VSM), and Fourier transform infrared spectroscopy (FT-IR). The heating ability was evaluated under a magnetic field using a solid state induction heating equipment at 10.2 kA/m and 362 kHz. The MagNPs-PNVCL nanocomposites showed a behavior close to superparamagnetic materials, which is appropriated for magnetic hyperthermia treatment; in concentrations of 8 mg/mL, they were able to heat up, increasing the temperature up to 42°C in a period of time lower than 10 minutes.

APA, Harvard, Vancouver, ISO, and other styles

25

Etemadifar, Reza, Abbas Kianvash, Nasser Arsalani, Ebrahim Abouzari-Lotf, and Abdollah Hajalilou. "Green synthesis of superparamagnetic magnetite nanoparticles: effect of natural surfactant and heat treatment on the magnetic properties." Journal of Materials Science: Materials in Electronics 29, no. 20 (August 13, 2018): 17144–53. http://dx.doi.org/10.1007/s10854-018-9805-6.

Full text

APA, Harvard, Vancouver, ISO, and other styles

26

Illés, Erzsébet, Etelka Tombácz, Zsófia Hegedűs, and Tamás Szabó. "Tunable Magnetic Hyperthermia Properties of Pristine and Mildly Reduced Graphene Oxide/Magnetite Nanocomposite Dispersions." Nanomaterials 10, no. 12 (December 4, 2020): 2426. http://dx.doi.org/10.3390/nano10122426.

Full text

Abstract:

We present a study on the magnetic hyperthermia properties of graphene oxide/magnetite (GO/MNP) nanocomposites to investigate their heat production behavior upon the modification of the oxidation degree of the carbonaceous host. Avoiding the harsh chemical conditions of the regular in situ co-precipitation-based routes, the oppositely charged MNPs and GO nanosheets were combined by the heterocoagulation process at pH ~ 5.5, which is a mild way to synthesize composite nanostructures at room temperature. Nanocomposites prepared at 1/5 and 1/10 GO/MNP mass ratios were reduced by NaBH4 and L-ascorbic acid (LAA) under acidic (pH ~ 3.5) and alkaline conditions (pH ~ 9.3). We demonstrate that the pH has a crucial effect on the LAA-assisted conversion of graphene oxide to reduced GO (rGO): alkaline reduction at higher GO loadings leads to doubled heat production of the composite. Spectrophotometry proved that neither the moderately acidic nor alkaline conditions promote the iron dissolution of the magnetic core. Although the treatment with NaBH4 also increased the hyperthermic efficiency of aqueous GO/MNP nanocomposite suspensions, it caused a drastic decline in their colloidal stability. However, considering the enhanced heat production and the slightly improved stability of the rGO/MNP samples, the reduction with LAA under alkaline condition is a more feasible way to improve the hyperthermic efficiency of magnetically modified graphene oxides.

APA, Harvard, Vancouver, ISO, and other styles

27

Ganapathe, Lokesh Srinath, Jamal Kazmi, Mohd Ambri Mohamed, and Dilla Duryha Berhanuddin. "Molarity Effects of Fe and NaOH on Synthesis and Characterisation of Magnetite (Fe3O4) Nanoparticles for Potential Application in Magnetic Hyperthermia Therapy." Magnetochemistry 8, no. 11 (November 21, 2022): 161. http://dx.doi.org/10.3390/magnetochemistry8110161.

Full text

Abstract:

In this study, the effect of molarity on the structural, magnetic, and heat dissipation properties of magnetite nanoparticles (MNPs) was investigated to optimise the parameters for potential application in magnetic hyperthermia therapy (MHT). MHT works based on the principle of local temperature rise at the tumour site by magnetic iron oxide nanoparticles (MIONPs) with the application of an alternating magnetic field. MHT is a safe method for cancer treatment and has minimal or no side effects. Magnetite (Fe3O4) is the best material among MIONPs to be applied in local MHT due to its biocompatibility and high saturation magnetisation value. MNPs were prepared by co-precipitation at varying molarity. Structural characterisation was performed via X-ray powder diffraction (XRD) for crystalline structure analysis and field-emission scanning electron microscopy (FESEM) for morphology and particle size analysis. Measurement of the magnetic properties of the as-synthesised MNPs was carried out using a vibrating sample magnetometer (VSM). Power loss (P) was determined theoretically. The increase in molarity resulted in significant effects on the structural, magnetic, and heat dissipation properties of MNPs. The particle size and saturation magnetisation (Ms) decreased with the gradual addition of base but increased, together with crystallinity, with the gradual addition of iron source. M3 recorded the smallest crystalline size at 3.559 nm. The sample with the highest molarity (M4) displayed the highest heat generation capacity with a p value of up to 0.4056 W/g. High p values at the nano-scale are crucial, especially in local MHT, for effective heat generation, thus proving the importance of molarity as a vital parameter during MNP synthesis.

APA, Harvard, Vancouver, ISO, and other styles

28

Santana, Geovana L., Murilo C. Crovace, Ernesto E. Mazón, Adilson J. A. de Oliveira, Theo Z. Pavan, and Edgar D. Zanotto. "Smart Bone Graft Composite for Cancer Therapy Using Magnetic Hyperthermia." Materials 15, no. 9 (April 28, 2022): 3187. http://dx.doi.org/10.3390/ma15093187.

Full text

Abstract:

Magnetic hyperthermia (MHT) is a therapy that uses the heat generated by a magnetic material for cancer treatment. Magnetite nanoparticles are the most used materials in MHT. However, magnetite has a high Curie temperature (Tc~580 °C), and its use may generate local superheating. To overcome this problem, strontium-doped lanthanum manganite could replace magnetite because it shows a Tc near the ideal range (42–45 °C). In this study, we developed a smart composite formed by an F18 bioactive glass matrix with different amounts of Lanthanum-Strontium Manganite (LSM) powder (5, 10, 20, and 30 wt.% LSM). The effect of LSM addition was analyzed in terms of sinterability, magnetic properties, heating ability under a magnetic field, and in vitro bioactivity. The saturation magnetization (Ms) and remanent magnetization (Mr) increased by the LSM content, the confinement of LSM particles within the bioactive glass matrix also caused an increase in Tc. Calorimetry evaluation revealed a temperature increase from 5 °C (composition LSM5) to 15 °C (LSM30). The specific absorption rates were also calculated. Bioactivity measurements demonstrated HCA formation on the surface of all the composites in up to 15 days. The best material reached 40 °C, demonstrating the proof of concept sought in this research. Therefore, these composites have great potential for bone cancer therapy and should be further explored.

APA, Harvard, Vancouver, ISO, and other styles

29

Lee, Chung-Hyo. "Nanocrystalline Formation and Magnetic Properties in Fe2O3–C System by Mechanical Alloying." Journal of Nanoscience and Nanotechnology 21, no. 7 (July 1, 2021): 3791–94. http://dx.doi.org/10.1166/jnn.2021.19228.

Full text

Abstract:

The effect of mechanical alloying (MA) on the solid state reaction of hematite and graphite system with a positive reaction heat was investigated using a mixture of elemental Fe2O3–C powders. The solid state reduction of hematite to Fe3O4 has been obviously observed after 3 hours of MA by a vibrating ball mill. A two-phase mixture of Fe3O4 and remaining Fe2O3 is obtained after 5 hours of MA. Saturation magnetization gradually increases with MA time due to the formation of Fe3O4 and then reaches 23 emu/g after 5 hours of MA. In addition, a Fe3O4 single phase is obtained by MA after 3 hours and subsequently heat treated up to 700°C. X-ray diffraction result shows that the average grain size of Fe3O4 prepared by MA for 5 hours and heat treatment to be in the range of 92 nm. The saturation magnetization of Fe3O4 prepared by MA and heat treatment reaches a maximum value of 56 emu/g for 5 hours MA sample. It is also observed that the coercivity of 5 hours MA sample annealed at 700 °C is still high value of 113 Oe, suggesting that the grain growth of magnetite phase during annealing process tends to be suppressed.

APA, Harvard, Vancouver, ISO, and other styles

30

Miryuk, Olga. "Environmental Aspects of Resource-Saving Cement Technology." Environmental and Climate Technologies 25, no. 1 (January 1, 2021): 803–15. http://dx.doi.org/10.2478/rtuect-2021-0060.

Full text

Abstract:

Abstract The article outlines the main problems that the cement industry causes to the environment. Authors propose technological solutions aimed at resource-saving in cement production and environmental protection. The research is devoted to low-energy cement obtained on the basis of waste from processing skarn-magnetite ores. The characteristics of the composition and properties of the technogenic material are given. The authors have justified the feasibility of using skarn-magnetite ore enrichment waste as a part of a cement raw material mixture. The possibility of changing the composition of cement by reducing the energy-intensive alite phase is demonstrated. Technological and heat engineering calculations confirming the reduction of natural mineral raw materials and fuel costs in the production of cement were carried out. The processes of hydration of the developed cements have been investigated. A method for accelerating the hardening of low-base cements due to mechanical activation, the introduction of mineral additives and a modifier is proposed. The research revealed construction and technological advantages of the developed cements, which exhibit increased resistance during operation in an aggressive environment. Physical and mechanical tests of concretes made of low-base cement were carried out. The possibility of reducing the temperature during the heat treatment of concrete is proved. Physical and mechanical tests of concretes made of low-base cement were carried out. The paper presents environmental benefits of the developed cement technology.

APA, Harvard, Vancouver, ISO, and other styles

31

Hayashi, Koichiro, Atsuto Tokuda, Jin Nakamura, Ayae Sugawara-Narutaki, and Chikara Ohtsuki. "Tearable and Fillable Composite Sponges Capable of Heat Generation and Drug Release in Response to Alternating Magnetic Field." Materials 13, no. 16 (August 17, 2020): 3637. http://dx.doi.org/10.3390/ma13163637.

Full text

Abstract:

Tearable and fillable implants are used to facilitate surgery. The use of implants that can generate heat and release a drug in response to an exogenous trigger, such as an alternating magnetic field (AMF), can facilitate on-demand combined thermal treatment and chemotherapy via remote operation. In this study, we fabricated tearable sponges composed of collagen, magnetite nanoparticles, and anticancer drugs. Crosslinking of the sponges by heating for 6 h completely suppressed undesirable drug release in saline at 37 °C but allowed drug release at 45 °C. The sponges generated heat immediately after AMF application and raised the cell culture medium temperature from 37 to 45 °C within 15 min. Heat generation was controlled by switching the AMF on and off. Furthermore, in response to heat generation, drug release from the sponges could be induced and moderated. Thus, remote-controlled heat generation and drug release were achieved by switching the AMF on and off. The sponges destroyed tumor cells when AMF was applied for 15 min but not when AMF was absent. The tearing and filling properties of the sponges may be useful for the surgical repair of bone and tissue defects. Moreover, these sponges, along with AMF application, can facilitate combined thermal therapy and chemotherapy.

APA, Harvard, Vancouver, ISO, and other styles

32

Cerra Florez, Mauro Andres, Gemma Fargas Ribas, Jorge Luiz Cardoso, Antonio Manuel Mateo García, Joan Josep Roa Rovira, Moises Bastos-Neto, Hamilton Ferreira Gomes de Abreu, and Marcelo José Gomes da Silva. "Oxidation Behavior of Maraging 300 Alloy Exposed to Nitrogen/Water Vapor Atmosphere at 500 °C." Metals 11, no. 7 (June 24, 2021): 1021. http://dx.doi.org/10.3390/met11071021.

Full text

Abstract:

Aging heat treatments in maraging steels are fundamental to achieve the excellent mechanical properties required in several industries, i.e., nuclear, automotive, etc. In this research, samples of maraging 300 alloy were aged using a novel procedure that combines different steps with two atmospheres (nitrogen and water vapor) for several hours. The oxidized surface layer was chemical, microstructural and micromechanically characterized. Due to the thermodynamic and kinetic conditions, these gases reacted and change the surface chemistry of this steel producing a thin iron-based oxide layer of a homogeneous thickness of around 500 nm. Within the aforementioned information, porosity and other microstructural defects showed a non-homogeneous oxide, mainly constituted by magnetite, nickel ferrite, cobalt ferrite, and a small amount of hematite in the more external parts of the oxide layer. In this sense, from a chemical point of view, the heat treatment under specific atmosphere allows to induce a thin magnetic layer in a mixture of iron, nickel, and cobalt spinel ferrites. On the other hand, the oxide layer presents an adhesive force 99 mN value that shows the capability for being used for tribological applications under sliding contact tests.

APA, Harvard, Vancouver, ISO, and other styles

33

Semko, L. S., L. P. Storozhuk, S. V. Khutornyi, and P. P. Gorbyk. "Transformations of Titanium(IV) Butoxide on Magnetite Surface in the Presence of Pluronic P-123." Фізика і хімія твердого тіла 16, no. 1 (March 15, 2015): 128–35. http://dx.doi.org/10.15330/pcss.16.1.128-135.

Full text

Abstract:

The technique of producing magnetically operated nanocomposites Fe3O4/TiO2 with high specific surface area (to 320 m2/g) was developed. A copolymer poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (Pluronic-123) was used as a template. The processes of converting n-butylortotytanatu (BOT) in TiO2 on the surface of magnetite in the presence of PL when heated, and the structure, magnetic and adsorption properties of nanocomposites Fe3O4/TiO2 were investigated. It is shown that the maximum temperature of the heat treatment of nanocomposites is 500 ºC. It was established that the specific saturation magnetization (σs) of nanocomposites Fe3O4/TiO2 by varying the content of PL ranges from 3.75 to 3.96 μT·m3/kg, while coercive force Hc – 1.47-1.61 kA/m. Adsorption complexes such as Fe3O4/TiO2/DNA were obtained.

APA, Harvard, Vancouver, ISO, and other styles

34

Chang, Chiung-Fen, and I. Peng Tseng. "Degradation of phenol by using magnetic photocatalysts of titania." Water Science and Technology 67, no. 7 (April 1, 2013): 1434–41. http://dx.doi.org/10.2166/wst.2013.669.

Full text

Abstract:

Magnetic TiO2 (MT) composites were prepared and applied to degrading phenol, which is one of the listed priority pollutants. The effects of heat treatment under preparation on the photocatalytic activity of MT composites have been investigated by varying the soaking time under a constant final temperature of 823 K. The total organic carbon and ring-remaining intermediates of o-DHB, p-DHB and 1,4-BQ in solution were detected during the photodegradation of phenol. All the resulting MT composites were the single-phase anatase and magnetite judged by X-ray diffraction patterns. The calcination of the as-prepared particles was proven to be extremely crucial to the photocatalytic activity. The best condition of heat treatment was found to be soaking time of 2 h at T = 823 K due to the good performance of photocatalytic activity, stable magnetic property, and reusability over three times. The results lead to the conclusion that recyclable MT composites prepared in this study, which belonged to the category of recyclable green materials, exhibit good photocatalytic activity to degrade phenol so as to possess applicable potential for the degradation of refractory organics in the aqueous solution. Furthermore, the environmental and health impacts were reduced as MT composites were applied in the treatment of water pollution.

APA, Harvard, Vancouver, ISO, and other styles

35

Yang, He, Ming Long Ma, Ming Lei Gao, Xiang Xin Xue, and You Quan Tang. "Research on Heat Treatment Process of Foam Glass Prepared by Titania-Bearing Blast Furnace Slag." Advanced Materials Research 79-82 (August 2009): 1587–90. http://dx.doi.org/10.4028/www.scientific.net/amr.79-82.1587.

Full text

Abstract:

Foam glass insulation materials were made by using titania-bearing blast furnace slag. Heat treatment process including foaming temperature, foaming time and heating rate were studied and their parameters were determined. First of all, heat treatment process parameter was determined by single factor experiment. Second, optimum process parameters of heat treatment process were obtained by the optimization of orthogonalization procedure. The results showed that foaming temperature has a remarkable effect on sample pore structure ；Foaming time has a less effect on pore distribution but its effect on the diameter of the pore is obvious; Heating rate has a less effect on the diameter of the pore. The magtitude of impact of heat treatment on glass properties arrange in an order of foaming temperature, foaming time and heating rate. The Optimal parameters of heat treatment are that heating rate ,foaming temperature and foaming time are 12°C/min，900°C, 15min respectively ; After preheating, sintering, foaming and foam stability and annealing heat treatment process, an amorphous foam glass with uniform pore size was obtained. Its thermal conductivity coefficient, the bulk density, compressive strength and average diameter are 0.131w / m ∙ k, 445.8 kg/m3, 2.8MPa, 4.78mm respectively. This kind of material can be widely used in building, chemical and shipbuilding industry as thermal insulation, sound absorption, corrosion-resistant and floating materials. Titania-bearing blast furnace slag is solid waste generated from vanadium-titanium magnetite by the blast furnace smelting, which is accumulated without being utilized. At present, Titania-bearing blast furnace slag is mainly used for cement concrete admixture, preparation of photocatalytic materials, extraction of titanium dioxide etc [1-2].Foam glass has been playing a more important role in low-temperature thermal insulation and moisture-proof anticorrosive projects field, and getting more economic benefits in energy saving and technology field. At present, the stuff for preparing foam glass is solid waste including waste glass, fly ash, slag, or natural minerals such as ash, mica, perlite etc. Foaming agent is usually selected from Carbon and carbonate [3-6]. In this paper, foam glass insulation materials were made by using titania-bearing blast furnace slag-based stuff. The effect of heat treatment process on foam glass performance was studied in a bid to find a new way to utilize titania-bearing blast furnace.

APA, Harvard, Vancouver, ISO, and other styles

36

Kozenkova, Elena, Kateryna Levada, Maria V. Efremova, Alexander Omelyanchik, Yulia A. Nalench, Anastasiia S. Garanina, Stanislav Pshenichnikov, et al. "Multifunctional Fe3O4-Au Nanoparticles for the MRI Diagnosis and Potential Treatment of Liver Cancer." Nanomaterials 10, no. 9 (August 21, 2020): 1646. http://dx.doi.org/10.3390/nano10091646.

Full text

Abstract:

Heterodimeric nanoparticles comprising materials with different functionalities are of great interest for fundamental research and biomedical/industrial applications. In this work, Fe3O4-Au nano-heterostructures were synthesized by a one-step thermal decomposition method. The hybrid nanoparticles comprise a highly crystalline 12 nm magnetite octahedron decorated with a single noble metal sphere of 6 nm diameter. Detailed analysis of the nanoparticles was performed by UV-visible spectroscopy, magnetometry, calorimetry and relaxometry studies. The cytotoxic effect of the nanoparticles in the human hepatic cell line Huh7 and PLC/PRF/5-Alexander was also assessed. These Fe3O4-Au bifunctional nanoparticles showed no significant cytotoxicity in these two cell lines. The nanoparticles showed a good theranostic potential for liver cancer treatment, since the r2 relaxivity (166.5 mM−1·s−1 and 99.5 mM−1·s−1 in water and HepG2 cells, respectively) is higher than the corresponding values for commercial T2 contrast agents and the Specific Absorption Rate (SAR) value obtained (227 W/gFe) is enough to make them suitable as heat mediators for Magnetic Fluid Hyperthermia. The gold counterpart can further allow the conjugation with different biomolecules and the optical sensing.

APA, Harvard, Vancouver, ISO, and other styles

37

Gorbyk, P. P., A. L. Petranovska, N. V. Kusyak, N. M. Korniichuk, A. P. Kusyak, O. I. Oranska, T. V. Kulyk, B. B. Palianytsia, and O. A. Dudarko. "Adsorption of cisplatin by the surface of the magnetic sensitive nanocomposite Fe3O4/Al2O3/С." Himia, Fizika ta Tehnologia Poverhni 12, no. 4 (December 30, 2021): 291–300. http://dx.doi.org/10.15407/hftp12.04.291.

Full text

Abstract:

One of the most widely used antitumor chemotherapeutic drugs is “Cisplatin” (active substance - cis-diaminodichloroplatinum), the side effects of which are the cumulative ototoxic, nephrotoxic and neurotoxic effects. The use of drug carrier systems for targeted delivery and adsorbents for extraction, in particular magnetite-carbon nanocomposites, will minimize unwanted toxic effects without reducing the therapeutic effect of cisplatin. For this purpose, a nanocomposite (NCs) of Fe3O4/Al2O3/С with a carbon surface was synthesized, where a layer of alumina protects magnetite during the pyrolysis of carbohydrates. The synthesized samples were characterized by TEM, XRD, mass spectrometry methods, magnetic properties and specific surface area were studied. It has been found that the used heat treatment mode (T = 500 °С, argon medium) is sufficient for complete carbonization of sucrose and preserves the phase of magnetite which does not lead to deterioration of magnetic characteristics. The results of TEM studies and magnetic measurements indicate the formation of the Fe3O4/Al2O3/С nanocomposite of the core-shell type. The adsorption of Cisplatin on the surface of NCs Fe3O4/Al2O3/С was performed and the adsorption process dependent on the contact time, pH of the solution and cisplatin concentration was studied. The experimental results of kinetic studies were analyzed for compliance with the theoretical models of Boyd and Morris-Weber, models of pseudo-first and pseudo-second orders. Langmuir and Freundlich isotherm models were used to model adsorption processes. The limiting factor of adsorption is the external diffusion mass transfer processes, which correlates with the calculated parameters of the pseudo-first-order model (r2 = 0.985). The correlation of theoretical and practically obtained values of adsorption capacity indicates the possibility of using the Freundlich model to describe the adsorption of Cisplatin on the surface of Fe3O4/Al2O3/C.

APA, Harvard, Vancouver, ISO, and other styles

38

Fatima, Maryam, Ayesha Sohail, Khush Bakhat Akram, Lubna Sherin, Saad Ihsan Butt, M. Abid, and O. Anwar Bég. "BIOMECHANICS OF SUPERPARAMAGNETIC NANOPARTICLES FOR LASER HYPERTHERMIA." Biomedical Engineering: Applications, Basis and Communications 32, no. 01 (February 2020): 2050007. http://dx.doi.org/10.4015/s1016237220500076.

Full text

Abstract:

Nanoparticle hyperthermia treatment is progressing with the passage of time, and with the development in the field of hybrid nanoparticles synthesis. The transient heat transfer in magnetite–graphene nanocomposite in three dimension under conduction is studied during this research. The proposed model is simulated in finite element solver framework. Novel hybrid nanoparticles were synthesized. Their chemical properties and their heat transfer properties were examined. By mathematical modeling results, the effective hybrid nanoparticle is chosen that can be used as a drug in hyperthermia process. Current developments in nanotechnology have improved the ability to precisely modify the features and properties of MNPs for these biomedical applications. The accurate control on the magnetic properties of the particle is the key in hyperthermia applications. By these magnetic particles, wished temperature can be achieved for laser hyperthermia. In this paper, study is done for understanding the properties and novelty of the new nanoparticles. The merits and demerits of synthesized hybrid nanoparticles are also discussed either the composites can used as a drug or not.

APA, Harvard, Vancouver, ISO, and other styles

39

Saranya, Shekar, Qasem M. Al-Mdallal, and Shumaila Javed. "Shifted Legendre Collocation Method for the Solution of Unsteady Viscous-Ohmic Dissipative Hybrid Ferrofluid Flow over a Cylinder." Nanomaterials 11, no. 6 (June 8, 2021): 1512. http://dx.doi.org/10.3390/nano11061512.

Full text

Abstract:

A numerical treatment for the unsteady viscous-Ohmic dissipative flow of hybrid ferrofluid over a contracting cylinder is provided in this study. The hybrid ferrofluid was prepared by mixing a 50% water (H2O) + 50% ethylene glycol (EG) base fluid with a hybrid combination of magnetite (Fe3O4) and cobalt ferrite (CoFe2O4) ferroparticles. Suitable parameters were considered for the conversion of partial differential equations (PDEs) into ordinary differential equations (ODEs). The numerical solutions were established by expanding the unknowns and employing the truncated series of shifted Legendre polynomials. We begin by collocating the transformed ODEs by setting the collocation points. These collocated equations yield a system of algebraic equations containing shifted Legendre coefficients, which can be obtained by solving this system of equations. The effect of the various influencing parameters on the velocity and temperature flow profiles were plotted graphically and discussed in detail. The effects of the parameters on the skin friction coefficient and heat transfer rates were further presented. From the discussion, we come to the understanding that Eckert number considerably decreases both the skin friction coefficient and the heat transfer rate.

APA, Harvard, Vancouver, ISO, and other styles

40

Du, Yong Sheng, Bao Wei Li, and Xue Feng Zhang. "Effects of Glass Components Ratio on Structure and Properties of Baiyunebo Tailing Glass-Ceramics." Materials Science Forum 743-744 (January 2013): 720–24. http://dx.doi.org/10.4028/www.scientific.net/msf.743-744.720.

Full text

Abstract:

Glass-ceramic in the CaO-MgO-Al2O3-SiO2 quaternary system was prepared using Baiyunebo tailing and fly ash as main raw materials by the method of melting. The processes of producing glass-ceramic included mixture, melting, molding, annealing, heat treatment, etc. The processing schedule for glass melting temperature, nucleation and crystallization temperature were chosen as 1450°C, 720°C and 850°C. The influences of glass components ratio on the structure were investigated by X-ray diffraction (XRD). It can be found that the main crystalline phase of augite, anorthite, magnesioferrite or magnetite mainly depended on glass components ratio. The results of mechanical measurements indicated that the bending strengths, density and chemical durability of glass-ceramics were concerned with the main crystal phase. The glass ceramics with augite phase had higher performance compared with others.

APA, Harvard, Vancouver, ISO, and other styles

41

Zhang, Xiaoping, Jun Wang, and Miao Gao. "Finite-size scaling law in single-crystalline Fe3O4 hollow nanostructures." Modern Physics Letters B 30, no. 21 (August 10, 2016): 1650241. http://dx.doi.org/10.1142/s0217984916502419.

Full text

Abstract:

Single-crystalline Fe3O4 hollow nanostructures (nanoring and nanotube) have been successfully synthesized by a hydrothermal method along with a heat treatment process. The temperature dependences of the magnetization of the hollow nanostructures were measured under a high vacuum ([Formula: see text] Torr) from 300[Formula: see text]K to 900[Formula: see text]K. The Curie temperatures of the nanoring and nanotube samples were found to decrease with decreasing the mean wall thickness. The Curie temperatures of the hollow magnetite nanostructures follow a finite-size scaling relation with the scaling exponent [Formula: see text]. By comparison with those of the zero-dimensional Fe3O4 particles and two-dimensional Fe3O4 films, we show that the scaling relation for our hollow nanostructures is in better agreement with the quasi-two-dimensional finite-size scaling law.

APA, Harvard, Vancouver, ISO, and other styles

42

Dvorikov, R. A., V. A. Vasnev, А. А. Korlukov, and М. I. Buzin. "MAGNETIC AND THERMAL PROPERTIES OF NANOMATERIALS BASED ON HIGHLY BRANCHED FERROCENE-CONTAINING POLYMERS." Fine Chemical Technologies 13, no. 5 (October 28, 2018): 49–57. http://dx.doi.org/10.32362/2410-6593-2018-13-5-49-57.

Full text

Abstract:

New magnetic nanomaterials with magnetization up to 32 Gs·cm3/g were synthesized from highly branched ferrocene-containing polymers by thermal structural transformations in a field of 2.5 kOe. The structure and properties of the prepared polymers were studied by IR spectroscopy, transmission electron microscopy (TEM) and thermogravimetric analyses. According to IR spectroscopy the content of 1,3,5-substituted benzene rings in the ferrocene-containing polymer increases at 500°C. X-ray diffraction study showed that iron in such a sample is present exclusively in the form of Fe3O4 magnetite. As the heating temperature increased to 600°C, the composition of the samples became more complex: along with magnetite they contain cementite Fe3C and wustite FeO.97O. The magnetization of the ferrocene-containing polymer depends on the synthesis and heat treatment temperature. For a sample synthesized at 140°C the formation of a magnetically ordered phase begins at 500°C, and at 800°C the magnetization reaches a maximum value of 32 Gs·cm3/g. The average size of magnetic particles according to TEM analysis was 8-26 nm. The principal possibility of controlling the size and composition of the nanoparticles, as well as their magnetization depending on the conditions of production and the temperature of polymer structuring is shown. The obtained results provide a good basis for the directed synthesis of magnetic ferrocene-containing polymers with preset characteristics.

APA, Harvard, Vancouver, ISO, and other styles

43

Zhang, Rui, Benjamin Fellows, Nikorn Pothayee, Nan Hu, Nipon Pothayee, Ami Jo, Ana C. Bohórquez, et al. "Ammonium Bisphosphonate Polymeric Magnetic Nanocomplexes for Platinum Anticancer Drug Delivery and Imaging with Potential Hyperthermia and Temperature-Dependent Drug Release." Journal of Nanomaterials 2018 (August 5, 2018): 1–14. http://dx.doi.org/10.1155/2018/4341580.

Full text

Abstract:

Novel magnetite-ammonium bisphosphonate graft ionic copolymer nanocomplexes (MGICs) have been developed for potential drug delivery, magnetic resonance imaging, and hyperthermia applications. The complexes displayed relatively uniform sizes with narrow size distributions upon self-assembly in aqueous media, and their sizes were stable under simulated physiological conditions for at least 7 days. The anticancer drugs, cisplatin and carboplatin, were loaded into the complexes, and sustained release of both drugs was observed. The transverse NMR relaxivities (r2s) of the complexes were 244 s−1 (mM Fe)−1 which is fast compared to either the commercial T2-weighted MRI agent Feridex IV® or our previously reported magnetite-block ionomer complexes. Phantom MRI images of the complexes demonstrated excellent negative contrast effects of such complexes. Thus, the bisphosphonate-bearing MGICs could be promising candidates for dual drug delivery and magnetic resonance imaging. Moreover, the bisphosphonate MGICs generate heat under an alternating magnetic field of 30 kA·m−1 at 206 kHz. The temperature of the MGIC dispersion in deionized water increased from 37 to 41°C after exposure to the magnetic field for 10 minutes, corresponding to a specific absorption rate of 77.0 W·g−1. This suggests their potential as hyperthermia treatment agents as well as the possibility of temperature-dependent drug release, making MGICs more versatile in potential drug delivery applications.

APA, Harvard, Vancouver, ISO, and other styles

44

Zhao, Dong Lin, Xian Wei Zeng, Qi Sheng Xia, and Jin Tian Tang. "Fe₃O₄/Polyaniline Nanoparticles with Core-Shell Structure and their Inductive Heating Property in AC Magnetic Field." Key Engineering Materials 334-335 (March 2007): 1189–92. http://dx.doi.org/10.4028/www.scientific.net/kem.334-335.1189.

Full text

Abstract:

The magnetite (Fe3O4) nanoparticles were prepared by coprecipitation of Fe3+ and Fe2+ with aqueous NaOH solution. The Fe3O4/polyaniline (PANI) magnetic composite nanoparticles with core-shell structure with diameter of 30-50 nm were prepared via an in-situ polymerization of aniline in aqueous solution containing Fe3O4 magnetic fluid. The inductive heat property of Fe3O4/polyaniline composite nanoparticles in an alternating current (AC) magnetic field was investigated. The potential of Fe3O4/polyaniline nanoparticles was evaluated for localized hyperthermia treatment of cancers. The saturation magnetization Ms and coercivity Hc of Fe3O4 nanoparticles are 50.05 emu/g and 137 Oe respectively, the Fe3O4/polyaniline composite nanoparticles, 26.34 emu/g and 0 Oe. Exposed in the alternating current (AC) magnetic field for 29 min, the temperatures of physiological saline suspension containing Fe3O4 nanoparticles or Fe3O4/polyaniline composite nanoparticles are 63.6 °C and 52.4 °C respectively. The Fe3O4/polyaniline composite nanoparticles would be useful as good thermoseeds for localized hyperthermia treatment of cancers.

APA, Harvard, Vancouver, ISO, and other styles

45

Li, Ong Huey, Liew Yun-Ming, Heah Cheng-Yong, Ridho Bayuaji, Mohd Mustafa Al Bakri Abdullah, Foo Kai Loong, Tan Soo Jin, et al. "Evaluation of the Effect of Silica Fume on Amorphous Fly Ash Geopolymers Exposed to Elevated Temperature." Magnetochemistry 7, no. 1 (January 6, 2021): 9. http://dx.doi.org/10.3390/magnetochemistry7010009.

Full text

Abstract:

The properties of amorphous geopolymer with silica fume addition after heat treatment was rarely reported in the geopolymer field. Geopolymer was prepared by mixing fly ash and alkali activator. The silica fume was added in 2% and 4% by weight. The geopolymer samples were cured at room temperature for 28 days before exposed to an elevated temperature up to 1000 °C. The incorporation of 2% silica fume did not cause significant improvement in the compressive strength of unexposed geopolymer. Higher silica fume content of 4% reduced the compressive strength of the unexposed geopolymer. When subjected to elevated temperature, geopolymer with 2% silica fume retained higher compressive strength at 1000 °C. The addition of silica fume in fly ash geopolymer caused a lower degree of shrinkage and expansion, as compared to geopolymer without the addition of silica fume. Crystalline phases of albite and magnetite were formed in the geopolymer at 1000 °C.

APA, Harvard, Vancouver, ISO, and other styles

46

Chen, Zhiyuan, Jie Dang, Xiaojun Hu, and Hongyan Yan. "Reduction Kinetics of Hematite Powder in Hydrogen Atmosphere at Moderate Temperatures." Metals 8, no. 10 (September 23, 2018): 751. http://dx.doi.org/10.3390/met8100751.

Full text

Abstract:

Hydrogen has received much attention in the development of direct reduction of iron ores because hydrogen metallurgy is one of the effective methods to reduce CO2 emission in the iron and steel industry. In this study, the kinetic mechanism of reduction of hematite particles was studied in a hydrogen atmosphere. The phases and morphological transformation of hematite during the reduction were characterized using X-ray diffraction and scanning electron microscopy with energy dispersive spectroscopy. It was found that porous magnetite was formed, and the particles were degraded during the reduction. Finally, sintering of the reduced iron and wüstite retarded the reductive progress. The average activation energy was extracted to be 86.1 kJ/mol and 79.1 kJ/mol according to Flynn-Wall-Ozawa (FWO) and Starink methods, respectively. The reaction fraction dependent values of activation energy were suggested to be the result of multi-stage reactions during the reduction process. Furthermore, the variation of activation energy value was smoothed after heat treatment of hematite particles.

APA, Harvard, Vancouver, ISO, and other styles

47

Baek, Inseok, and Seoksoon Lee. "A Study of Films Incorporating Magnetite Nanoparticles as Susceptors for Induction Welding of Carbon Fiber Reinforced Thermoplastic." Materials 13, no. 2 (January 10, 2020): 318. http://dx.doi.org/10.3390/ma13020318.

Full text

Abstract:

Induction welding is a fast, clean, noncontact process that often uses a metal-mesh susceptor to facilitate localized controlled heating; however, the metal mesh presents various problems. In this study, the induction heating behavior of a 450 μ m thick thin-film susceptor, fabricated by mixing magnetite (Fe 3 O 4 ) nanoparticles (NPs) and PA6/carbon fiber (CF) (30%) thermoplastic resin, was examined with respect to the weight ratio of Fe 3 O 4 (50, 67, 75, and 80 wt%). The useful induction heating behavior of the 75 wt% Fe 3 O 4 susceptor suggested its suitability for additional heat treatment experiments, carried out at 3.4 kW at a frequency of 100 kHz. This susceptor attained the same maximum temperature during 10 cycles of repeated induction heating and cooling. It was then used to weld two thermoplastic composites, with 60 s of induction heating followed by 120 s of simultaneous cooling and pressing. The resulting welded joints had lap shear strength values of 36.8, 34.0, and 36.4 MPa under tensile test loads of 884, 817, and 874 N, respectively. Scanning electron microscopy images confirmed a uniform weld quality. Thus, the proposed manufacturing method, involving the incorporation of Fe 3 O 4 NPs into thermoplastic resin, should help expand the range of applications for thermoplastic composites.

APA, Harvard, Vancouver, ISO, and other styles

48

Pavlyukevich, Yu G., L. F. Papko, M. M. Hundzilovich, P. S. Larionov, and A. A. Uvarov. "Phase separation and properties of glasses of the system MgO–CaO–Fe 2O3–Al2O3–В2O3–SiO2." Proceedings of the National Academy of Sciences of Belarus, Chemical Series 58, no. 3 (September 7, 2022): 317–24. http://dx.doi.org/10.29235/1561-8331-2022-58-3-317-324.

Full text

Abstract:

The synthesis and study of model glasses of the MgO–CaO–Fe2O3–Al2O3–SiO2 system, which is the base for obtaining continuous basalt fiber, has been carried out. Systematized data on the effect of components on the glasses structure and the sequence of phase separation processes occurring during their heat treatment have been obtained. It is shown that during phase separation, crystalline phases are separated in the following sequence: magnetite–pyroxene–plagioclase with a predominance of the anorthite component. Glasses of the MgO–CaO–Fe2O3–Al2O3–SiO2 system were modified by adding B2O3, and the active role of this component in the processes of glass formation and crystallization was shown. The ratio of glass-forming and modifying components of model glasses is established, at which an increase in the strength of glasses from 110 to 180 MPa is achieved. Based on the study of the technological properties of model glasses and strength characteristics, components were determined for modifying basalt glasses in order to increase the strength of the fiber.

APA, Harvard, Vancouver, ISO, and other styles

49

Balaško, Tilen, Barbara Šetina Batič, Jožef Medved, and Jaka Burja. "High-Temperature Oxidation Behaviour of Duplex Fe-Mn-Al-Ni-C Lightweight Steel." Crystals 12, no. 7 (July 8, 2022): 957. http://dx.doi.org/10.3390/cryst12070957.

Full text

Abstract:

Lightweight Fe-Mn-Al-Ni-C steels are an attractive material, due to the combination of low density, high elongation, and yield strength. However, the high Al content is also interesting from the point of view of high-temperature resistance. High-temperature resistance is important for high-temperature applications and oxidation during heat treatment. Oxidation tests at 700, 800 and 900 °C were carried out to investigate the oxidation rates. Oxidation at 700 °C resulted in slight decarburisation, which was reflected in a slight weight loss in the thermogravimetric analysis. In contrast, the weight in the thermogravimetric analysis increased at 800 and 900 °C and the kinetics followed a parabolic law. The higher the temperature, the more weight is gained and the thicker the oxide layer becomes. The oxidation layer at 800 and 900 °C consisted mainly of hematite and magnetite, with minor amounts of wüstite, alumina and hercynite. Preferential oxidation of austenite was also observed, as it has an increased Mn content. In addition, ferrite had an increased content of Al and Ni, which provide additional oxidation resistance.

APA, Harvard, Vancouver, ISO, and other styles

50

Bensalah, Nasr, Emna Neily, Ahmed Bedoui, and Mohammad I. Ahmad. "Mineralization of Riluzole by Heterogeneous Fenton Oxidation Using Natural Iron Catalysts." Catalysts 13, no. 1 (December 30, 2022): 68. http://dx.doi.org/10.3390/catal13010068.

Full text

Abstract:

Fenton (H2O2/Fe2+) system is a simple and efficient advanced oxidation technology (AOT) for the treatment of organic micropollutants in water and soil. However, it suffers from some drawbacks including high amount of the catalyst, acid pH requirement, sludge formation and slow regeneration of Fe2+ ions. If these drawbacks are surmounted, Fenton system can be the best choice AOT for the removal of persistent organics from water and soil. In this work, it was attempted to replace the homogeneous catalyst with a heterogeneous natural iron-based catalyst for the decomposition of H2O2 into oxidative radical species, mainly hydroxyl (HO•) and hydroperoxyl radicals (HO2•). The natural iron-based catalyst is hematite-rich (α-Fe2O3) and contains a nonnegligible amount of magnetite (Fe3O4) indicating the coexistence of Fe (III) and Fe(II) species. A pseudo-first order kinetics was determined for the decomposition of H2O2 by the iron-based solid catalyst with a rate constant increasing with the catalyst dose. The catalytic decomposition of H2O2 into hydroxyl radicals in the presence of the natural Fe-based catalyst was confirmed by the hydroxylation of benzoic acid into salicylic acid. The natural Fe-based catalyst/H2O2 system was applied for the degradation of riluzole in water. It was demonstrated that the smaller the particle size of the catalyst, the larger its surface area and the greater its catalytic activity towards H2O2 decomposition into hydroxyl radicals. The degradation of riluzole can occur at all pH levels in the range 3.0–12.0 with a rate and efficiency greater than H2O2 oxidation alone, indicating that the natural Fe-based catalyst can function at any pH without the need to control the pH by the addition of chemicals. An improvement in the efficiency and kinetics of the degradation of riluzole was observed under UV irradiation for both homogeneous and heterogeneous Fenton systems. The results chromatography analysis demonstrate that the degradation of riluzole starts by the opening of the triazole ring by releasing nitrate, sulfate, and fluoride ions. The reuse of the catalyst after heat treatment at 500 °C demonstrated that the heat-treated catalyst retained an efficiency >90% after five cycles. The results confirmed that the natural sources of iron, as a heterogeneous catalyst in a Fenton-like system, is an appropriate replacement of a Fe2+ homogeneous catalyst. The reuse of the heterogeneous catalyst after a heat-treatment represents an additional advantage of using a natural iron-based catalyst in Fenton-like systems.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Magnetite Heat treatment'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles