Synthesis of Porous Basic Magnesium Carbonate Crystallographic Materials with Flower-Like Structure

2016 ◽  
Vol 723 ◽  
pp. 444-449 ◽  
Author(s):  
Juan Chen ◽  
Zhi Liang Huang ◽  
Wen Zhao Li

The porous basic magnesium carbonate (Mg5(CO3)4(OH)2.4H2O) crystal crystallographic materials with flower-like structure were prepared successfully by homogeneous precipitation method. Magnesium chloride hexahydrate (MgCl2.6H2O) and urea (CO(NH2)2) wereused as reaction materials. The experimental equipment was held at 100°C for 8 h. Phase and morphology of the product were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The formation mechanism of the product was investigated. It was found that the CO2 bubbles acted as porous templates. The growth and gathering of the CO2 bubbles induced the growth of the MgCO3.3H2O columnar crystals. Then the dissolution of the MgCO3.3H2O and the deposition of Mg5(CO3)4(OH)2.4H2O happened simultaneously. Finally the disappearance of MgCO3.3H2O brought about the formation of the porous structure.

2016 ◽  
Vol 16 (4) ◽  
pp. 3886-3889 ◽  
Author(s):  
Hongquan Yu ◽  
Ye Qi ◽  
Yanbo Wu ◽  
Jinsu Zhang ◽  
Baojiu Chen

Y2O3:Tb3+ nanoballs were synthesized via the urea homogeneous precipitation method (UPM). The resulting Y2O3:Tb3+ phosphors were characterized by X-ray diffraction (XRD), scanning electron microscopy, ultraviolet-visible (UV-vis) absorption spectra, and general photoluminescence spectra. The particle sizes estimated using X-ray diffractometry and scanning electron microcopy were about 50–200 nm. The emission intensity of the Y2O3:Tb3+ was low when the doping concentrations of Tb3+ were higher. The optimum concentration of Tb3+ for synthesis of Y2O3:Tb3+ nanocrystals is 1%.


2011 ◽  
Vol 284-286 ◽  
pp. 684-687
Author(s):  
Chang Yu Li ◽  
Li Li Liu ◽  
Shou Xin Liu

Without using any templates or surfactants, flowerlike α-nickel hydroxide (Ni(OH)2) was successfully synthesized by homogeneous precipitation method. The prepared products were characterized by X-ray powder diffraction (XRD), high-resolution transmission electron microscopy (HRTEM) and N2 adsorption-desorption. The prepared Ni(OH)2 is α-phase with specific surface area of 245.0 m2/g and shows flowerlike structure with 4-6 um in diameter.


2021 ◽  
Author(s):  
Fatma Unal

Abstract Terbium oxide (Tb2O3) particles (NPs) were synthesized by precipitation method using ammonium carbonate as precipitation agent. Effects of precursor molarity (0.1, 0.15 and 0.2 M) on photoluminescence (PL) behaviour of the NPs were investigated. The presence of the Tb2O3 phase was confirmed by X-Ray Diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR) analyses. Morphological investigations of the produced powders were made by Field Emission Gun-Scanning Electron Microscopy (FEG-SEM). It showed that the morphology of Tb2O3 particles transformed from the nanograin chain to bundles morphology of rod-like as the amount of precursor molarity increased. Emission spectrum were investigated by Photoluminescence (PL) Spectroscopy. All the Tb2O3 particles exhibited the strongest peak at 493 nm ascribed to 5D4-7F6 (magnetic dipole (MD), C2) transition. The increase in the number of C2 sites released from the MD transition with the increase of the precursor molarity caused a negative increase in the b* (yellowness/blueness of the emission) value in the CIE diagram, indicating that the colour shifted to the blue region. The Tb2O3 particles produced by the precipitation method exhibited novel strong cyan colour and the PL emission intensity increased with increasing molarity.


2021 ◽  
Vol 234 ◽  
pp. 00106
Author(s):  
Houda Labjar ◽  
Hassan Chaair

The synthesis of apatite silicated Ca10(PO4)6-x(SiO4)x(OH)2-x (SiHA) with 0≤x≤2 was investigated using a wet precipitation method followed by heat treatment using calcium carbonate CaCO3 and phosphoric acid H3PO4 and silicon tetraacetate SiC8H20O4 (TEOS) in medium of water ethanol, with three different silicate concentrations. After drying, the samples are ground and then characterized by different analytical techniques like X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning electron Microscopy (SEM) and chemical analysis.


Cerâmica ◽  
2016 ◽  
Vol 62 (363) ◽  
pp. 278-280 ◽  
Author(s):  
T. H. A. Corrêa ◽  
J. N. F. Holanda

Abstract Calcium pyrophosphate (CPP) was prepared by a simple precipitation method using avian eggshell waste as a low-cost alternative calcium precursor source. The synthesized CPP powder was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM/EDS), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR). The results indicate that pure β-CPP nanocrystallites (Ca/P = 1.067) were successfully synthesized from avian eggshell waste. The correlation among XRD, SEM/EDS, TGA, and FTIR data is well established. The β-CPP particle exhibited spherical morphology with average crystallite size of 62.3 nm, and can be an important bioceramic for medical applications.


2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Rodholfo da Silva Barbosa Ferreira ◽  
Caio Henrique do Ó Pereira ◽  
Rene Anisio da Paz ◽  
Amanda Melissa Damião Leite ◽  
Edcleide Maria Araújo ◽  
...  

The nanocomposites have an extensive use in the current process of membrane preparation, taking into account their unique features as membranes. Thus, the study of nanocomposite processing to obtain membranes is highly important. In this work, Brazilian clay was used (Brasgel PA) for the preparation of polyamide/clay nanocomposite. The nanocomposites were produced in a high rotation homogenizer and in a twin screw extruder. From the nanocomposites and pure polymers processed in the two equipments, membranes were prepared by the immersion-precipitation method, using formic acid as solvent. By X-ray diffraction (XRD), the formation of exfoliated and/or partially exfoliated structures with changes in the crystalline phases of the polyamide was observed. From scanning electron microscopy images, it was observed that the processing clearly influenced the membrane morphology.


2010 ◽  
Vol 148-149 ◽  
pp. 1551-1555
Author(s):  
Yan Hong Zhao ◽  
Qing Yue Jia ◽  
You Gao ◽  
Xiao Jing Wang

Strontium carbonate particles with different morphologies and sizes were synthesized successfully by a precipitation method in the presence of ethylenediaminetetra-acetic acid disodium (abbreviate as EDTA) at 25 . The phase structure and morphology of these SrCO3 particles were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The XRD results showed that orthorhombic crystalline SrCO3 particles were prepared in the absence of and presence of EDTA. It was found that this additive played an important role in controlling the morphology and size of the particles, which changed from dendritic to spherical shape as EDTA was added.


2013 ◽  
Vol 32 (1) ◽  
pp. 47-50
Author(s):  
Guo Chen ◽  
Jin Chen ◽  
Lijun Liu ◽  
C. Srinivasakannan ◽  
Jinhui Peng

AbstractBaCO3 nanoparticles with different morphologies including needle-like, rod-like, bird's nest-like and flower-like have been successfully synthesized by the microwave homogeneous precipitation method using BaCl2·2H2O, NaOH and (NH2)2CO as raw materials with the help of different guide reagents, such as citric acid (CA), sodium triphosphate (STPP) and ethylene diamine tetraacetic acid (EDTA). Their phases and morphologies were characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM), respectively. The characterization results show that different guide reagents have little effect on the phase structure and composition of products while they play significant roles in determining the morphology of products. All the synthesized BaCO3 nanoparticles have typical orthorhombic structures that are well-crystallized.


2013 ◽  
Vol 454 ◽  
pp. 288-291 ◽  
Author(s):  
Jian An Liu ◽  
Mei Mei Zhang ◽  
Xue Na Yang

A novel porous ferromagnetic glass-ceramic has been synthesized with glassceramic and hydroxyapatite for hyperthermia application. The glassceramic was obtained from a melt derived glass, and the hydroxyapatite was prepared via precipitation method with biological template (YEAST). Both components of such a mixture were sintered at 1000 °C for 1 hour in graphite. The sample was characterized by x-ray diffraction, scanning electron microscopy and magnetic measurements. This material exhibited magnetic behavior and porosity. The results show that porous ferromagnetic glass-ceramic, which saturation magnetization (Ms) of about 25 A·m2/kg and diameter of porous 30-50μm, was obtained.


2008 ◽  
Vol 135 ◽  
pp. 23-26 ◽  
Author(s):  
So Jin Kim ◽  
Won Kyu Han ◽  
Sung Goon Kang ◽  
Min Su Han ◽  
Young Hun Cheong

Lanthanum hydroxide and oxide were prepared by the precipitation method in an aqueous medium at room temperature. The precipitate was examined using thermal analysis, X-ray diffraction and Scanning Electron Microscopy to investigate the phase evaluation and the thermal transformation by decomposition. The as-precipitated powder from the precipitation method was hexagonal La(OH)3. The lanthanum hydroxide was decomposed to oxide in two-steps as La(OH)3 → LaOOH + H2O and 2LaOOH → La2O3 + H2O.


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