Energetic and magnetic directional aggregation properties of KPA@Fe3O4 composite particles prepared via a microcrystalline co-precipitation route

2021 ◽  
Author(s):  
Yongpeng Chen ◽  
Jianguo Zhang ◽  
Ying Li ◽  
Jiawei Zhang ◽  
Huichao Zhang ◽  
...  

Abstract The development of new electromagnetic interference materials has attracted much attention in the information warfare. Herein, a novel KPA@Fe3O4 composite particle was synthesized via a microcrystalline co-precipitation method. X-ray diffractions, scanning electron microscopes and vibrating sample magnetometer measurements were used to characterize the products. The results indicated that the surface of the potassium picrate (KPA) crystals was covered by magnetic Fe3O4 nanoparticles, and composite particles exhibited excellent magnetic properties. Furthermore, the thermal behavior of the composite particles was investigated by differential scanning calorimetry, which showed that the composite particles inherited the energetic property of pure KPA crystals when the mass fraction of magnetic component was 50%, or 65%. As for the composite particles with 75% magnetic component, the thermal stability of was poor. In addition, the magnetic directional aggregation performance of composite particles was analyzed by dynamic simulation, which moved toward the magnetic source. For the composite particles with 50% magnetic component, the maximum concentration was about 63 times of the initial concentration, and the peak velocity was 0.63 m/s. With the mass fraction of magnetic component increasing to 65%, the concentration and velocity of the composite particles generally increased at the corresponding moment. As the mass fraction of magnetic component increased to 75%, the change of them was not obvious. Therefore, the composite particles with Fe3O4/KPA mass ratios of 65/35 had the best comprehensive properties. The excellent energetic and magnetic directional aggregation properties can allow the composites to be used in many potential applications in the information warfare.

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4021
Author(s):  
Andrés Esteban Cerón Cerón Cortés ◽  
Anja Dosen ◽  
Victoria L. Blair ◽  
Michel B. Johnson ◽  
Mary Anne White ◽  
...  

Materials from theA2M3O12 family are known for their extensive chemical versatility while preserving the polyhedral-corner-shared orthorhombic crystal system, as well as for their consequent unusual thermal expansion, varying from negative and near-zero to slightly positive. The rarest are near-zero thermal expansion materials, which are of paramount importance in thermal shock resistance applications. Ceramic materials with chemistry Al2−xInxW3O12 (x = 0.2–1.0) were synthesized using a modified reverse-strike co-precipitation method and prepared into solid specimens using traditional ceramic sintering. The resulting materials were characterized by X-ray powder diffraction (ambient and in situ high temperatures), differential scanning calorimetry and dilatometry to delineate thermal expansion, phase transitions and crystal structures. It was found that the x = 0.2 composition had the lowest thermal expansion, 1.88 × 10−6 K−1, which was still higher than the end member Al2W3O12 for the chemical series. Furthermore, the AlInW3O12 was monoclinic phase at room temperature and transformed to the orthorhombic form at ca. 200 °C, in contrast with previous reports. Interestingly, the x = 0.2, x = 0.4 and x = 0.7 materials did not exhibit the expected orthorhombic-to-monoclinic phase transition as observed for the other compositions, and hence did not follow the expected Vegard-like relationship associated with the electronegativity rule. Overall, compositions within the Al2−xInxW3O12 family should not be considered candidates for high thermal shock applications that would require near-zero thermal expansion properties.


2015 ◽  
Vol 1112 ◽  
pp. 489-492
Author(s):  
Ali Mufid ◽  
M. Zainuri

This research aims to form particles of hematite (α-Fe2O3) with a basis of mineral iron ore Fe3O4 from Tanah Laut. Magnetite Fe3O4 was synthesized using co-precipitation method. Further characterization using X-ray fluorescence (XRF) to obtain the percentage of the elements, obtained an iron content of 98.51%. Then characterized using thermo-gravimetric analysis and differential scanning calorimetry (TGA-DSC) to determine the calcination temperature, that at a temperature of 445 °C mass decreased by 0.369% due to increase in temperature. Further Characterization of X-ray diffraction (XRD) to determine the phases formed at the calcination temperature variation of 400 °C, 445 °C, 500 °C and 600 °C with a holding time of 5 hours to form a single phase α-Fe2O3 hematite. Testing with a particle size analyzer (PSA) to determine the particle size distribution, where test results indicate that the α-Fe2O3 phase of each having a particle size of 269.7 nm, 332.2 nm, 357.9 nm, 412.2 nm. The best quantity is shown at a temperature of 500 °C to form the hematite phase. This result is used as the calcination procedure to obtain a source of Fe ions in the manufacture of Lithium Ferro Phosphate.


2016 ◽  
Vol 875 ◽  
pp. 24-44
Author(s):  
Ming Guo Ma ◽  
Shan Liu ◽  
Lian Hua Fu

CaCO3 has six polymorphs such as vaterite, aragonite, calcite, amorphous, crystalline monohydrate, and hexahydrate CaCO3. CaCO3 is a typical biomineral that is abundant in both organisms and nature and has important industrial applications. Cellulose could be used as feedstocks for producing biofuels, bio-based chemicals, and high value-added bio-based materials. In the past, more attentions have been paid to the synthesis and applications of CaCO3 and cellulose/CaCO3 nanocomposites due to its relating properties such as mechanical strength, biocompatibility, and biodegradation, and bioactivity, and potential applications including biomedical, antibacterial, and water pretreatment fields as functional materials. A variety of synthesis methods such as the hydrothermal/solvothermal method, biomimetic mineralization method, microwave-assisted method, (co-) precipitation method, and sonochemistry method, were employed to the preparation of CaCO3 and cellulose/CaCO3 nanocomposites. In this chapter, the recent development of CaCO3 and cellulose/CaCO3 nanocomposites has been reviewed. The synthesis, characterization, and biomedical applications of CaCO3 and cellulose/CaCO3 nanocomposites are summarized. The future developments of CaCO3 and cellulose/CaCO3 nanocomposites are also suggested.


2019 ◽  
Vol 967 ◽  
pp. 259-266 ◽  
Author(s):  
Muhammad Rizal Fahlepy ◽  
Yuyu Wahyuni ◽  
Muhamma Andhika ◽  
Arini Tiwow Vistarani ◽  
Subaer

This research is about nanoparticles hematite (NPH) synthesized and characterized from natural iron sands using co-precipitation method and its potential applications as extrinsic semiconductor materials type-N. The aims of this study is to determine the process parameters to obtain hematite of high purity degree and to observe its physical characteristics as an extrinsic semiconductor materials type-N. The iron sand was first separated by magnetic technique and then dissolved into HCl solution before conducting the precipitation process. Precipitation was done by dripping ammonium hydroxide (NH4OH). Precipitated powder was dried at 80°C for 2 hours, and then calcined at 500°C, 600°C 700°C for 2 hours respectively. The composition of iron sands, purity degree, hematite mineral grain size, and space group were analyzed by XRF, XRD, FTIR and SEM. The XRF analysis result of raw material, showed that dominant element and composition in the sample is Fe with purity degree is 90.51%. The XRD result before and after precipitation showed Fe3O4 and α-Fe2O3. Fe3O4 purity degree was obtained 85%, and α-Fe2O3 in NPH500, NPH600, NPH700 were 63%, 83%, and 76%, respectively. FTIR spectral showed crystalline hematite characteristics stong band of 472.07 to 559.62 cm-1. SEM image showed the morphology of agglomeration particulates, when the calcinaton temperature increases, the agglomeration will be seperated due to thermal energy. Based on the charaterization results it was found that the natural iron sand synthesized has the potential to be applied as an N-type extrinsic semiconductor material.


2007 ◽  
Vol 14 (06) ◽  
pp. 1135-1141 ◽  
Author(s):  
JIE-GUANG SONG ◽  
LIAN-MENG ZHANG ◽  
JUN-GUO LI ◽  
JIAN-RONG SONG

Although Zirconium diboride ( ZrB 2) is a desirable combination with some good properties, it is easily oxidized in the high-temperature air to impact high-temperature properties, which dwindles the applied range. In order to decrease oxidization and improve the high-temperature properties of ZrB 2, the surface of ZrB 2 is coated with Al ( OH )3– Y ( OH )3 to synthesize Al ( OH )3– Y ( OH )3/ ZrB 2 composite particles. In this paper, the conditions of synthesizing Al ( OH )3– Y ( OH )3/ ZrB 2 composite particles by the co-precipitation method are investigated. Al ( OH )3– Y ( OH )3/ ZrB 2 composite particles are synthesized under different conditions, but the conditions of synthesizing Al ( OH )3– Y ( OH )3/ ZrB 2 composite particles with the better coating quality require pH = 9, the appropriate concentration ( Al 3+ = 0.017 mol/L , Y 3+ = 0.01 mol/L ) of composite solution, reaction time of 60 min, titration speed of 0.05 ml/s, using the dispersant in the ZrB 2 suspension and the ultrasonic dispersion, respectively.


2016 ◽  
Vol 855 ◽  
pp. 47-53
Author(s):  
Ampa Jimtaisong ◽  
Nisakorn Saewan

Inclusion complex of β-cyclodextrin (β-CD) and Plai (Zingiber cassumunar) oil was prepared using a simple co-precipitation method at β-CD to Plai oil in different ratios. The inclusion complexes were characterized using Fourier transform-infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC). The FT-IR absorption bands of inclusion complex at 3600-3200 cm-1 were broader and shifted toward lower frequencies compared with that of pure β-CD (3359 cm-1). DSC of the inclusion complexes showed two endothermic peaks shifted to lower temperatures (90-100°C and 295-300°C) compared to that of β-CD. The different physicochemical characteristic could be an indication of an embedded guest molecule in the β-CD cavities in the inclusion complex preparation.


2007 ◽  
Vol 14 (01) ◽  
pp. 117-122 ◽  
Author(s):  
JIEGUANG SONG ◽  
LIANMENG ZHANG ◽  
JUNGUO LI ◽  
JIANRONG SONG

ZrB 2 has some excellent performances, but it is easily oxidized at high temperatures to impact the high-temperature strength, which restricts its applied range. To protect from the oxidization and improve the strength of ZrB 2 at high temperature, the surface of ZrB 2 particles is coated with the Al ( OH )3– Y ( OH )3 shell to synthesize ZrB 2@ Al ( OH )3– Y ( OH )3 core–shell composite particles. Through the thermodynamic and kinetic analyses of the heterogeneous nucleation and homogeneous nucleation, the concentration product of precursor ion ( Y 3+ or Al 3+) and OH - (Qi) must be greater than the solubility product (K sp ), respectively; the conditions of Y 3+ and Al 3+ are reached to produce Al ( OH )3– Y ( OH )3 shell on the ZrB 2 surface between the Y 3+ line and the AlO 2- line. Through TEM and XRD analyses, ZrB 2@ Al ( OH )3– Y ( OH )3 core–shell composite particles are successfully synthesized by the co-precipitation method, the shell layer quality is better at pH = 9, which established the foundation for preparing high-performance YAG / ZrB 2 and Al 2 O 3– YAG / ZrB 2 multiphase ceramic materials.


2018 ◽  
Vol 55 (1B) ◽  
pp. 7 ◽  
Author(s):  
Dai Hai Nguyen

The objective of this study is to prepare biodegradable iron oxide nanoparticles with gelatin (GEL) for paclitaxel (PTX) delivery. In detail, Fe3O4 nanoparticles were prepared and then coated them with GEL (Fe3O4@GEL) conjugate by co–precipitation method. Furthermore, the formation of Fe3O4@GEL was demonstrated by Fourier transform infrared (FT–IR) and powder X–ray diffraction (XRD). The superparamagnetic property of Fe3O4@GEL was also showed by hysteresis loop analysis, the saturation magnetization reached 20.36 emu.g–1. In addition, size and morphology of Fe3O4@GEL nanoparticles were determined by transmission electron microscopy (TEM). The results indicated that Fe3O4@GEL nanoparticles were spherical shape with average diameter of 10 nm. Especially, PTX was effectively loaded into the coated magnetic nanoparticles, 86.7 ± 3.2 % for drug loading efficiency and slowly released up to 5 days. These results suggest that the potential applications of Fe3O4@GEL nanoparticles in the development of stable drug delivery systems for cancer therapy.


2016 ◽  
Vol 16 (4) ◽  
pp. 3547-3556 ◽  
Author(s):  
Errui Yang ◽  
Guangshe Li ◽  
Yunlong Zheng ◽  
Liping Li

Selective synthesis of specific phased nanomaterials via a green route is a promising yet challenging task. In the present work, the hexagonal and monoclinic phases of BiPO4:Ln3+ (Ln = Sm, Eu, Tb, Dy) were prepared via room temperature co-precipitation method. For adjusting the phase of the products, the prepared mediums selected were the most common solvents, i.e., water and ethanol. It was very important that the prepared mediums could be easily recycled and reused by evaporating the filtrate. The formation mechanisms of hexagonal in water and monoclinic in ethanol were investigated. Interestingly, the growth behaviors of these phases were quite distinct and thus gave rise to distinct morphology and particle size. The hexagonal phase possesses a rod-like morphology with diameters of 50–160 nm and lengths of 65–400 nm while the monoclinic phase consists of almost entirely irregular nanoparticles. Also, it was found that the bending and stretching vibrations of O–H and PO4 tetrahedra were quite different for the products prepared in water and ethanol. Moreover, it was found that the luminescence properties, including emission intensity, lifetime, quantum efficiency, and color, could be readily tailored through controlling the phase structures and microstructures. The results showed that the monoclinic phase exhibited superior luminescent performance to the hexagonal phase. The methodologies reported in this work were fundamentally important, which could be easily extended to large-scale synthesis of other phased nanomaterials for potential applications as electroluminescent devices, optical integrated circuits, or biomarkers.


2014 ◽  
Vol 07 (04) ◽  
pp. 1450038 ◽  
Author(s):  
Yanwei Dong ◽  
Ming Kang ◽  
Ping Zhang ◽  
Qijun Cheng ◽  
Jie Wang

Phosphors based on calcium carbonate, co-doped with various Eu 3+ and Dy 3+ concentrations were prepared by microwave co-precipitation method. The prepared phosphors were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), thermogravimetry and differential scanning calorimetry (TG-DSC) and photoluminescence and photoluminescence excitation (PL-PLE) spectroscopy. Results showed that Dy 3+ and Eu 3+ ions were uniformly introduced into the host lattice of CaCO 3 taking the place of Ca 2+ ions. Under the excitation at 382 nm, the emission peak wavelengths were at 487 nm (4 F 9/2 → 6 H 15/2 of Dy 3+), 576 nm (4 F 9/2 → 6 H 13/2 of Dy 3+), and 614 nm (5 D 0 → 7 F 2 of Eu 3+). The luminescent intensities and emitting colors of Eu 3+- Dy 3+ co-doped CaCO 3 phosphors could be controlled by UV–violet excitations wavelengths or the rare-earth ions concentrations of Eu 3+ and Dy 3+ in phosphors. The chromaticity coordinates and photographs of samples under UV light showed the changes of the luminescence color intuitively through the varing UV–violet excitations wavelengths or the rare-earth ions concentrations of Eu 3+ and Dy 3+.


Sign in / Sign up

Export Citation Format

Share Document