scholarly journals Improvement of microwave absorption properties of polyester coatings using NiFe2O4, X-doped g-C3N4 (X = S, P, and O), and MTiO3 (M = Fe, Mg, and Zn) nanofillers

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Somayeh Solgi ◽  
Mir Saeed Seyed Dorraji ◽  
Seyyedeh Fatemeh Hosseini ◽  
Mohammad Hossein Rasoulifard ◽  
Ismael Hajimiri ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Microwave Absorption ◽  
High Efficiency ◽  
Sol Gel ◽  
X Ray ◽  
Transmission Electron ◽  
Effective Performance ◽  
The Matrix ◽  
Co Precipitation ◽  
Electromagnetic Pollution

AbstractIn recent decades, to reduce electromagnetic pollution, scientists focus on finding new microwave absorbers with effective performance, thin thickness, and broad bandwidth. In this work, the nanoparticles of NiFe2O4, X-doped g-C3N4 (M = S, P, and O), and MTiO3 (M = Fe, Mg, and Zn) were successfully synthesized using co-precipitation, specific heat program, and semi-wet sol–gel methods, respectively. The synthesized nanoparticles were utilized as absorption agents and polyester resin as the matrix. Morphology, particle size, crystal structure, and chemical composition of the prepared nanocomposites were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffractometer (XRD), and energy dispersive X-Ray analysis (EDX), respectively. The microwave absorption performance of the coatings was also investigated by a vector network analyzer (VNA). Moreover, the effect of different parameters on the performance of absorbent coatings was studied by the Taguchi method and optimized to achieve an optimal absorbent. The results showed that the optimal nanocomposite has the reflectance loss (RL) less than − 30 dB (equal to absorption > 99%) at a high-frequency range (8–12 GHz) and 1 mm thickness. Furthermore, the addition of such novel nanoparticles to absorbents resulted in high values of attenuation constant (more than 200 dB/m) at the X-band. Therefore, the polyester coating filled with ZnTiO3, O-doped g-C3N4, and NiFe2O4 nanofillers can be considered a high-efficiency and low-density absorber.

The Influence of Cu Dopant Concentration on the Optical Properties of Fe3O4/SiO2/TiO2 Nanocomposite

2019 ◽  
Vol 948 ◽  
pp. 260-266
Author(s):  
Aisyiah Restutiningsih Putri Utami ◽  
M. Sulthon Nurharman Syah Putra ◽  
M. Miqdam Musawwa ◽  
Eko Sri Kunarti
Keyword(s):  
Electron Microscope ◽  
Sol Gel ◽  
Aqueous Media ◽  
Band Gap Energy ◽  
X Ray ◽  
Optimum Result ◽  
Specular Reflectance ◽  
Transmission Electron ◽  
The Fourier Transform ◽  
Co Precipitation

Fe3O4/SiO2/TiO2dopped Cu with magnetic properties had been succesfully syntesized and characterized. The research was began with the synthesis of magnetite and magnetite covered by silica by co-precipitation and sonication method, and the preparation of Cu-doped TiO2using sol-gel method followed by calcination. The concentrations of Cu were 0%, 1%, 3%, 5%, and 7% (FST0, FST1, FST3, FST5, and FST7). The Fourier Transform Infra Red spectrophotometer (FTIR), X-Ray Diffractometer (XRD), Scanning Electron Microscope-Energy Dispersive X-ray spectrophotometer (SEM-EDX), UV-Specular Reflectance Spectrophotometer (SR-UV), and Transmission Electron Microscope (TEM) were used to characterize the nanocomposite and external magnetic bar was used to separate the nanocomposite in an aqueous media. The Cu concentration affected the band gap energy (Eg) and the optimum result was 2.832 eV in FST7. The best magnetic propertieswas material FST0. The time needed for separate this material with aqueous medium was 372 second.

Template Induced Synthesis of Nano-Hydroxyapatite by Co-Precipitation Method

2011 ◽  
Vol 311-313 ◽  
pp. 1713-1716 ◽  
Author(s):  
Yan Rong Sun ◽  
Tao Fan ◽  
Chang An Wang ◽  
Li Guo Ma ◽  
Feng Liu
Keyword(s):  
Electron Microscope ◽  
Chondroitin Sulfate ◽  
Aspartic Acid ◽  
Transmission Electron Microscope ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure And Morphology ◽  
Transmission Electron ◽  
Co Precipitation

Nano-hydroxyapatite with different morphology was synthesized by the co-precipitation method coupled with biomineralization using Ca(NO3)2•4H2O and (NH4)2HPO4 as reagents, adding chondroitin sulfate, agarose and aspartic acid as template. The structure and morphology of the prepared powders were characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM).

scholarly journals Effect of Preheating Temperature on Synthesis of Pure BiFeO3 via Sol–Gel Method

Nanopages ◽  
2019 ◽  
pp. 1-11
Author(s):  
G. M. Taha ◽  
M. N. Rashed ◽  
M. S. El-Sadek ◽  
M. A. Moghazy
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Pure Bifeo3 ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Transmission Electron ◽  
Preheating Temperature

Abstract BiFeO3 (BFO) nanopowder was synthesized in a pure form via a sol- gel method based on glycol gel reaction. Effect of drying and preheating temperature on preventing other phases was studied. Many parameters were studied as calcination temperature and time & stirring temperature as well. The prepared powder was characterized by X-Ray Diffraction of powder (XRD) and Transmission Electron Microscope (TEM). High pure BiFeO3 was obtained by preheated process at 400 °C for 0.5 h and calcination at 600 °C for 0.5 h without any impurities compared to dry at110 °C.

scholarly journals Fenton Degradation of Ofloxacin Using a Montmorillonite-Fe3O4 Composite

2020 ◽  
Vol 2 (1) ◽  
pp. 32
Author(s):  
Alamri Rahmah Dhahawi Ahmad ◽  
Saifullahi Shehu Imam ◽  
Wen Da Oh ◽  
Rohana Adnan
Keyword(s):  
Electron Microscope ◽  
Photoelectron Spectroscopy ◽  
High Efficiency ◽  
Solar Irradiation ◽  
Precipitation Process ◽  
Wastewater Remediation ◽  
Solution Ph ◽  
X Ray ◽  
Subsequent Degradation ◽  
Co Precipitation

In this work, FeM composites consisting of montmorillonite and variable amounts of Fe3O4 were successfully synthesized via a facile co-precipitation process. They were characterized using X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscope (FESEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscope (TEM), N2 adsorption-desorption, and Fourier transform infrared spectroscopy (FT-IR) techniques to explain the effect of Fe3O4 content on the physicochemical properties of the Fe3O4-montmorillonite (FeM) composites. The FeM composites were subsequently used as heterogeneous Fenton catalysts to activate green oxidant (H2O2) for the subsequent degradation of ofloxacin (OFL) antibiotic. The efficiency of the FeM composites was studied by varying various parameters of Fe3O4 loading on montmorillonite, catalyst dosage, initial solution pH, initial OFL concentration, different oxidants, H2O2 dosage, reaction temperature, inorganic salts, and solar irradiation. Under the conditions of 0.75 g/L FeM-10, 5 mL/L H2O2, and natural pH, almost 81% of 50 mg/L of OFL was removed within 120 min in the dark, while total organic carbon (TOC) reduction was about 56%. Moreover, the FeM-10 composite maintained high efficiency and was stable even after four continuous cycles, making it a promising candidate in real wastewater remediation.

MICROWAVE ABSORPTION BEHAVIOR OF MESOPOROUS TRANSITION METAL OXIDE TEMPLATED FROM SBA-15 AND KIT-6

2014 ◽  
Vol 28 (10) ◽  
pp. 1450037 ◽  
Author(s):  
HONGJING WU ◽  
LIUDING WANG ◽  
YIMING WANG
Keyword(s):  
Electron Microscope ◽  
Microwave Absorption ◽  
Absorption Characteristic ◽  
Chemical Compositions ◽  
X Ray Diffraction ◽  
Hard Template ◽  
Absorption Properties ◽  
Microwave Absorption Properties ◽  
X Ray ◽  
Transmission Electron

In this paper, we have synthesized meso-oxides (i.e., Co 3 O 4 and NiO ) by using mesoporous silica as hard template. The microstructures and chemical compositions of the corresponding meso-oxides were characterized by the Transmission electron microscope-selected area electron diffusion (TEM-SAED), X-ray diffraction (XRD), scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDS), respectively. And, their electromagnetic and microwave absorption properties were investigated in the frequency range of 2–18 GHz. The results indicate that meso-oxide templated from KIT-6 (i.e., meso-K– Co / Ni ) exhibit a dual absorption characteristic compared with those using SBA-15 as hard template. This phenomenon suggests that meso-oxides templated from SBA-15 and KIT-6 can exhibit different microwave absorption behaviors due to their respective microstructures.

Fabrication, Structural Characterization and Formation Mechanism of Multiferroic BiFeO3 Nanotubes

2008 ◽  
Vol 8 (1) ◽  
pp. 335-339 ◽  
Author(s):  
Satyendra Singh ◽  
S. B. Krupanidhi
Keyword(s):  
Electron Microscope ◽  
Formation Mechanism ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Multiferroic Bifeo ◽  
High Resolution Tem ◽  
Perovskite Crystal

Multiferroic BiFeO3 (BFO) nanotubes have been successfully fabricated by the modified sol–gel method within the nanochannels of porous anodic aluminum oxide (AAO) templates. The morphology, structure and composition of the nanotubes were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), selected-area electron diffraction (SAED), high resolution TEM, (HRTEM) and energy-dispersive X-ray spectroscopy (EDX). Postannealed (650 °C for 1 h), BFO nanotubes were polycrystalline and X-ray diffraction study revealed that they are of the rhomohedrally distorted perovskite crystal structure. The results of SEM and TEM revealed that BFO nanotubes possessed a uniform length (up to 60 μm) and diameter (about 200 nm), which were controlled by the thickness and the pore diameter of the applied AAO template, respectively and the thickness of the wall of the BFO nanotube was about 15 nm. Y-junctions in the BFO nanotubes were observed. EDX analysis demonstrated that stoichiometric BiFeO3 was formed. HRTEM analysis confirmed that the obtained BFO nanotubes made up of nanoparticles (3–6 nm). The possible formation mechanism of BFO nanotubes was discussed.

Nickel oxide–silica and nickel–silica aerogel and xerogel nanocomposite materials

2000 ◽  
Vol 15 (10) ◽  
pp. 2187-2194 ◽  
Author(s):  
M. F. Casula ◽  
A. Corrias ◽  
G. Paschina
Keyword(s):  
Nickel Oxide ◽  
Sol Gel ◽  
Supercritical Drying ◽  
Nanocomposite Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
The Matrix ◽  
Drying Conditions ◽  
Microscopy Techniques

The sol-gel method was used to prepare nickel oxide–silica and nickel–silica nanocomposite materials and the corresponding silica matrices. Different drying conditions were used to obtain aerogel and xerogel materials. The samples were characterized by thermal analysis, x-ray diffraction, N2–physisorption, transmission electron microscopy techniques, and infrared spectroscopy. Aerogel samples had a much higher surface area than the xerogel samples; moreover, different supercritical drying conditions gave rise to a different porous structure, which influenced the size and distribution of the nanoparticles in the matrix.

Loading of siRNA on Magnetic PLL-Fe2O3@SiO2 Nanocomposites and their Transfection In Vitro

2014 ◽  
Vol 1053 ◽  
pp. 444-449
Author(s):  
Xue Wen Cui ◽  
Gang Cheng ◽  
Rui Jiang Liu ◽  
Li Wei Wang ◽  
Yan Shuai Wang
Keyword(s):  
Electron Microscope ◽  
Precipitation Method ◽  
Blue Staining ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sd Rat ◽  
Gene Carriers ◽  
Transmission Electron ◽  
Co Precipitation

The magnetic Fe2O3 nanoparticles were prepared by co-precipitation method with FeCl3 and NaOH as starting reagents. The surface of Fe2O3 nanoparticles was modified with tetraethyl orthosilicate. Fe2O3@SiO2 nanocomposites were calcined at 600 °C. The nanocomposites were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX). The PLL-Fe2O3@SiO2 (SMNP) was prepared by modifying with poly-L-lysine on the surface. The SMNP combined with plasmid siRNA by static electrical charges as one of gene carriers was transfected into SD rat neurons. The results of fluorescence microscope and Prussian blue staining show that SMNP can effectively enter cells. Therefore, SMNP are one kind of novel and effective gene carriers, it can transfect the plasmid which carries the siRNA into SD rats neurons in vitro.

Investigation on Nano-Sized ZnO Powder Doped with Al3+ Prepared by Sol-Gel Method

2012 ◽  
Vol 621 ◽  
pp. 3-7
Author(s):  
Yu Xiong ◽  
Ji Zheng ◽  
Song Lin Li ◽  
Xue Jia Liu ◽  
Lu Liang
Keyword(s):  
Electron Microscope ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nano Powder ◽  
Transmission Electron ◽  
Sol Gel Process ◽  
Doped Zno ◽  
Zno Powder ◽  
Tin Tetrachloride

Al3+-doped ZnO nano-powder was prepared by sol-gel process, using tin tetrachloride and titanium tetrachloride as starting materials. The crystallinity and purity of the powder were analyzed by X-ray diffraction spectrometer (XRD). And the size and distribution of Al3+-doped ZnO grains were studied using transmission electron microscope (TEM) and scanning electron microscope (SEM). The results showed that the Al3+ was successfully doped into the crystal lattice of tin oxide and that the electric conductivity of Al3+-doped ZnO sample was improved significantly.

Microwave NIMs: Using a Uniform AC Electric Field for Manipulating Ag Nanorods Embedded in Co0.05Ti0.95O2 Matrix

NANO ◽  
2016 ◽  
Vol 11 (08) ◽  
pp. 1650084
Author(s):  
Zahra Khorshidi ◽  
Ali Bahari
Keyword(s):  
Electron Microscopy ◽  
Electric Field ◽  
Sol Gel ◽  
Negative Permittivity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ac Electric Field ◽  
Transmission Electron ◽  
Permittivity And Permeability ◽  
The Matrix

In the present work, we synthesized a composite medium consisting of Ag nanorods embedded in Co[Formula: see text]Ti[Formula: see text]O2 matrix (Ag/CTO) using the sol-gel method. We applied a uniform AC electric field at the beginning of gelation and during drying for manipulating Ag nanorods in the matrix. The structure and morphology characterizations of Ag/CTO nanocomposites were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques. The permittivity and permeability behaviors of samples were investigated. Results showed that for the sample dried in the existence of the electric field, simultaneous negative permittivity and permeability were realized. These results imply the realization of double negative properties in this sample. Therefore, this work suggests that Ag/Co[Formula: see text]Ti[Formula: see text]O2 nanocomposites can be introduced as a negative index metamaterials (NIMs).

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