scholarly journals Synthesis and characterization of a new magnetic composite MnFe2O4/clay based on a natural clay obtained from Turkestan deposit

2021 ◽  
Vol 104 (4) ◽  
pp. 87-94
Author(s):  
Zh.A. Baimuratova ◽  
◽  
M.S. Kalmakhanova ◽  
B.K. Massalimova ◽  
A.A. Nurlibaeva ◽  
...  

The work is devoted to the development of a new method for the synthesis of magnetic composites based on manganese ferrite on a natural clay, coupling with their physico-chemical characterization. In the study, a natural clay of Kazakhstan obtained from the Turkestan deposit was used for the preparation of magnetic composites. The formation of materials with magnetic properties is an urgent task of our time, due to the needs of various applications of magnetically controlled materials for biomedical systems, electronic devices, catalytic and adsorption processes. The advantage of such materials is the ability to control them using a magnetic field for shaking, recovery, induction heating, among others. In this work, samples were prepared by co-precipitation of manganese and iron salts with 5 mol L-1 NaOH over the Turkestan clay (TC). Materials were characterized by various analyses, such as Fourier-Transform infrared spectroscopy (FTIR), X-ray diffractometric analysis (XRD), and elemental analysis. According to the results of physical and chemical studies of the XRD and thermal analysis, kaolinite is the main mineral in the composition of TC. Magnetic adsorbents MnFe2O4/clay with perfect magnetic separation characteristics were successfully obtained by chemical co-precipitation

2005 ◽  
Vol 19 (12) ◽  
pp. 2053-2059
Author(s):  
JUN WANG ◽  
YUEJIN ZHU ◽  
QIANWANG CHEN

Nearly monodisperse silica spheres with a diameter of ~90 nm containing NiFe 2 O 4 nanoparticles were successfully prepared by hydrolysis of TEOS in the presence of NiFe 2 O 4 nanoparticles, synthesized through a hydrothermal method. The colloid particles were characterized by XRD, TEM and VSM. The results indicate that the particles possess better magnetic properties at room temperature, compared with paramagnetic colloids with magnetic core by co-precipitation method. The colloid particles assembled under additional magnetic fields could have potential application in biomedical systems.


Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1742
Author(s):  
Fatimah Mohammed Alzahrani ◽  
Norah Salem Alsaiari ◽  
Khadijah Mohammedsaleh Katubi ◽  
Abdelfattah Amari ◽  
Faouzi Ben Rebah ◽  
...  

A magnetic polymer-based nanocomposite was fabricated by the modification of an Fe3O4/SiO2 magnetic composite with polypyrrole (PPy) via co-precipitation polymerization to form PPy/Fe3O4/SiO2 for the removal of Congo red dye (CR) and hexavalent chromium Cr(VI) ions from water. The nanocomposite was characterized using various techniques including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), vibration sample magnetometer, and thermogravimetric analysis (TGA). The results confirm the successful fabrication of the nanocomposite in the size of nanometers. The effect of different conditions such as the contact time, adsorbent dosage, solution pH, and initial concentration on the adsorption process was investigated. The adsorption isotherm suggested monolayer adsorption of both contaminants over the PPy/Fe3O4/SiO2 nanocomposite following a Langmuir isotherm, with maximum adsorption of 361 and 298 mg.g−1 for CR dye and Cr(VI), respectively. Furthermore, the effect of water type on the adsorption process was examined, indicating the applicability of the PPy/Fe3O4/SiO2 nanocomposite for real sample treatment. Interestingly, the reusability of the nanocomposite for the removal of the studied contaminants was investigated with good results even after six successive cycles. All results make this nanocomposite a promising material for water treatment.


RSC Advances ◽  
2016 ◽  
Vol 6 (42) ◽  
pp. 35859-35867 ◽  
Author(s):  
Pinghua Chen ◽  
Weibo Zhang ◽  
Menglin Li ◽  
Peng Ai ◽  
Lei Tian ◽  
...  

A novel magnetic composite of La–Zr was prepared by co-precipitation method, and its fluoride removal ability was investigated in batch studies.


Molekul ◽  
2018 ◽  
Vol 13 (1) ◽  
pp. 63
Author(s):  
I Made Sadiana ◽  
Karelius Karelius ◽  
Retno Agnestisia ◽  
Abdul Hadjranul Fatah

Clay is a natural material from crystalline silicate with layered structures, has high cation exchange capacity, and large surface area. These advantages can be used as an adsorbent for the removal of contaminants in aqueous solutions, such as heavy metals and dyes. In Indonesia, clays from Java, Sulawesi, and Sumatra islands have been used as adsorbent, furniture, and construction materials. Due to limited information about basic characteristics of clay from Kalimantan, this clay has not been utilized well. Therefore, natural clay from Kalimantan, especially in Central Kalimantan, was used as adsorbent of cationic dyes in this present study. However, the clay has difficulty for separating the solid phase from aqueous solution after adsorption process. To solve this problem, combining clay with magnetic material was opted. The objectives of this study are to synthesize the magnetic composite material from natural clay by coprecipitation method and to characterize the synthesized magnetic composite material using an x-ray diffraction method, transmission electron microscopy, and vibrating sample magnetometer. The adsorption properties of the synthesized magnetic composite material were evaluated using rhodamine B and methylene blue dyes in aqueous solution. Before magnetic composite material was synthesized, the clay was previously being activated for removing impurities. The magnetic material formed in the structure of clay had magnetite with particle size of 2.75 nm and the magnetization value of 24.91emu/g. The adsorption capacities of natural clay, activated clay, and magnetic composite of clay in rhodamine B were 34.29, 76.27, and 81.46 mg/g, respectively, while in methylene blue were 30.25, 83.92, and 133.90 mg/g, respectively. These results suggested that magnetic composite of clay can increase the adsorption capacities against dyes and accelerate the separation of the adsorbent solid phase from aqueous solution with largest adsorption capacity on methylene blue dye.


Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3065
Author(s):  
Marek Przybylski ◽  
Barbara Ślusarek ◽  
Paolo Di Barba ◽  
Maria Evelina Mognaschi ◽  
Sławomir Wiak

Soft magnetic composite (SMC) materials made of iron powder are more frequently used in construction of electric actuators and motors because of their advantages with respect to Fe–Si electric steel sheets and because they have almost no powder loss. The study deals with measurements of temperature and torque of a low-power rotary switched reluctance actuator, with reference to a commercial actuator and a prototype actuator characterized by stator and rotor cores made of soft magnetic composite materials. Further power loss analysis was also conducted. To assess the actuators, magnetization characteristics and iron loss vs. magnetic flux density at a given frequency were measured according to IEC standards. Results show that the actuator made of soft magnetic composites exhibits higher efficiency and a lower temperature rise of stator and windings in comparison with the commercial actuator.


2020 ◽  
Vol 10 (22) ◽  
pp. 8155
Author(s):  
Antonio De Nino ◽  
Matteo Antonio Tallarida ◽  
Vincenzo Algieri ◽  
Fabrizio Olivito ◽  
Paola Costanzo ◽  
...  

Commercially available microcrystalline cellulose (MCC) was functionalized using chlorosulfonic acid, while iron oxide nanoparticles (IONPs) were adsorbed on the surface of the cellulose derivative by the Massart’s co-precipitation method. The obtained magnetite-decorated sulfate cellulose nanoparticles (MDSCNs) were characterized via Fourier transform infrared (FTIR) spectroscopy, scanning-electron microscopy (SEM), and elemental analysis, while the acidity of the functionalized cellulose was determined using an acid–base titration with phenolphthalein as an indicator. Furthermore, in order to determine the adsorptive power of the obtained composite, a series of analyses were performed on aqueous amine pollutants using flame ionization detection gas chromatography (GC-FID). The results of this study clearly show how a bio-compatible green polymer as cellulose can be easy functionalized in order to improve its chemical and physical properties, obtaining a magnetic composite useful in water purification. Adsorption percentages up to 90% and a very small amount of composite used (100 mg) proved how our material can be a powerful tool in environmental remediation.


2021 ◽  
pp. 65-71
Author(s):  
A. Stashevskyi

The relevance of the topic and problem statement. In the process of formation and development of the original style of button accordion music one of the most important roles is played by the factor of texture, which fully embodies the instrumental specificity of the button accordion, and reflects the originality of forms and varieties of musical fabric in button accordion works. The study of the peculiarities of texture organization, as well as highlighting the main trends in texture formation in modern button accordion music, in particular in the works of Ukrainian composers, is seen as an urgent task to understand the essence of the phenomenon of modern button accordion, and in general — to develop domestic musicology in instrumental art. In previous works of the author of this article, an attempt was made to systematize the textured formations of modern button accordion music, which are determined by the specifics of the design of button accordion keyboards (Stashevskyі, 2021). Continuing further study of the textured organization of modern music for button accordion, there is a need to identify and systematize other typical for this work samples of texture and its components, the structure of which is not due to the structural configuration of sound keys on button accordion keyboards. That is, those that are more universal, but, at the same time, are characterized as typical of modern button accordion art. The purpose of the study is to study the most typical textural elements and combinations of modern button accordion music, as well as their systematization based on the analysis of their internal structural organization. The methodology used in this article is based on the use of methods of theoretical musicology (primarily, analysis of elements of musical language and means of expression), as well as methods of structural and system analysis, generalization and classification. The results. The systematization of typical original texture formulas of modern button accordion creativity carried out in this work provides their division into certain groups and kinds (subgroups) in the middle of these groups, in particular: reverberation (chordal and mixed); stereophony (pulsation, transmission, unison); pedalling arpeggio (rhythmic, non­rhythmic); pedal scale (cluster crescendo); monophonic structural­modular constructions (chromatic by broken intervals; gamma­shaped­arpeggio based on a 5­element fingering group); chord transpositions (interval­algorithmic (chromatics; m3; m2­B2; etc.), thematic­melodic); simplified accompaniment (alternation of tessitura­polar sounds); multi­octave duplications (unison, decomposed­arpeggio). The topicality of the work lies in the fact that for the first time in modern musicology the textured elements of modern button accordion music have received analytical discourse and systematization. The practical significance of the work lies in the possibility of its use in theoretical courses on the study of button accordion art, as well as in the practical work of button accordionists. Conclusions. To sum up, we can state that the considered original textural elements and formulas are typical for modern button accordion music, as they occur in works in many cases. The typical button accordion texture formulas considered in this article, which are often found in the artistic plane of musical works, play an important role in the formation of a kind of stylistic handwriting of modern button accordion speech. At the same time, they, in contrast to the group of determinant texture formulas, reflect a certain universalism of their presentation, as they can be transferred to other instrumental texture (keyboard instruments) conditions and implemented in them.


Author(s):  
Yana Yu. Chernykh ◽  
Tatiana A. Vereshchagina ◽  
Elena V. Mazurova ◽  
Vladimir A. Parfenov ◽  
Leonid A. Solovyev ◽  
...  

Magnetic sorbents were prepared by addition of ferrospheres to zirconia-silica gel followed by thermal treatment at 500 °C. The ferrosphere narrow fraction E -0.063+0.050 mm from fly ash resulted from combustion of Ekibastuz coal was used as a magnetic component. The surface of magnetic composites was additionally functionalized by grafting of – POONa and – NH2 groups. Under equilibrium conditions sorption capacities of the sorbents with respect to Се3+ used as a U4+/Th4+ simulator and Pb2+ were measured by means of determination of sorption isotherms which were fitted by the Langmuir model. It was established that extraction of Се3+ and Pb2+ from aqueous solutions is characterized by distribution coefficients of 104–106 ml/g. Temperature conditions for solid-phase crystallization of the sorbents resulting in polyphase systems with the content of zircon phase of 50 wt. % were found


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