scholarly journals Morphology control of SrBi2Nb2O9 prepared by a modified chemical method

2019 ◽  
Vol 51 (4) ◽  
pp. 353-361
Author(s):  
Mohamed Afqir ◽  
Amina Tachafine ◽  
Didier Fasquelle ◽  
Mohamed Elaatmani ◽  
Jean-Claude Carru ◽  
...  

SrBi2NbO9 compounds were prepared through three methods: oxalate co-precipitation, molten salt synthesis and polymerizable complex. The effect of the molecular precursor route has also been investigated. For oxalate co-precipitation method, a solution obtained from acid oxalate, niobium oxide, bismuth nitrate and strontium nitrate are precipitated by ammoniac solution. Then, the precipitated sample is calcined at 1100?C. A methanol-citric acid solution of solution of NbCl5, ethylene glycol, bismuth and strontium nitrates were used as precursors. A black powder ash was crystallized by heat-treating at 1100?C. Molten salt technique using oxides and carbonate as starting materials and NaCl and KCl to form a reaction medium. The formation temperature was at 1110?C. Multiple characterizations mainly X-ray diffraction, Fourier transformed infrared spectroscopy and scanning electron microscopy (SEM) measurements have provided to validate the structural feature. Careful, X-ray diffraction analysis showed the presence of two-layered Aurivillius structure. The crystallite size is discussed by Scherrer and Williamson-Hall approaches. SEM images of SrBi2NbO9 ceramics showed plate-like, polygonal and structureless morphologies obtained at different synthesis conditions. Whatever the synthesis process, there is no change on the band of infrared spectra.

2008 ◽  
Vol 396-398 ◽  
pp. 497-500 ◽  
Author(s):  
S.L.F. Ramos ◽  
M. Motisuke ◽  
L.R. Rodrigues ◽  
Cecília A.C. Zavaglia

A lot of attention has been given to bone cements due to their lack of mechanical properties. The improvement of this property is essential, once it makes possible the usage of these biomaterials in sites that require a significant mechanical strength resistance. To do so, reinforcement agents, such as fibers, in particular biocompatible fibers, have been synthesized [1]. This study reports the synthesis of stequiometric Hydroxyapatite whisker-like fibers utilizing the Molten Salt Synthesis process of nanometric Hydroxyapatite with a salt flux mixture of KCl/NaCl. According to SEM images, EDS analysis and X-ray diffraction, the fibers obtained presented well defined and elongated (main length of about 70µm) hexagonal morphology with Ca/P ratio of 1.66.


2013 ◽  
Vol 838-841 ◽  
pp. 2306-2309
Author(s):  
Guang Hua Wang ◽  
Kun Chen ◽  
Wen Bing Li ◽  
Dong Wan ◽  
Qin Hu ◽  
...  

Magnetic modified organobentonite (Fe3O4/CTAB–Bent) was synthesized by chemical co-precipitation method in which CTAB–Bent was firstly achieved via ion–exchange.The composite materials have been characterized by powder X–ray diffraction (XRD), Fourier transform infrared spectroscopy (FT–IR) and Scanning electron microscopy (SEM) . The results revealed that basal spacing of bentonite was increased through organic modification and the Fe3O4 particles synthesized which covering the surfaces of bentonite .Compared with natural bentonite, the adsorption capacity of Fe3O4/CTAB–Bent for Orange II was greatly enhanced and can be easily separated from the reaction medium by an external magnetic field after the treatment.


2013 ◽  
Vol 645 ◽  
pp. 129-132 ◽  
Author(s):  
Jantasom Khanidtha ◽  
Suttinart Noothongkaew ◽  
Supakorn Pukird

SnO2-CuO nanocomposites have been synthesized with the simple co-precipitation method for gas sensing properties. Sn and CuO powder were the starting materials. The synthesized products were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that SnO2-CuO nanocomposites have a tetragonal and monoclinic structure, respectively. SEM images verify that the some microballs are up to 10 µm and nanorods have a diameter range from 10-100 nm, while length ranges a few micrometers. The nanocomposite products were highly sensitivity to CO2gas at room temperature.


2017 ◽  
Vol 7 (1) ◽  
pp. 27
Author(s):  
Husnah Rofiko ◽  
Yofentina Iriani ◽  
Risa Suryana

<p>Strontium Titanate (SrTiO<sub>3</sub>) with variation of sintering temperatures were prepared by co-precipitation methods. Sintering temperature were varied at 700<sup>o</sup>C, 800<sup>o</sup>C, and 900<sup>o</sup>C for 4 hours. SrTiO<sub>3</sub> samples were prepared by Strontium Nitrate and Titanium Tetrabutoxide. SrTiO<sub>3</sub> samples were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Resistance Capacitance Inductance (RCL) meter, and Sawyer Tower.  SEM images show that the sintering temperatures could affect the grain size of SrTiO<sub>3</sub>. In addition, crystal size of SrTiO<sub>3</sub> (110) affected by sintering temperature. The highest of dielectric constant is 137 on SrTiO<sub>3</sub> at sintering temperature of 900<sup>o</sup>C. Sawyer Tower curves confirmed that SrTiO3 has paraelectric property.</p><p>Keyword: Strontium Titanate, Co-precipitation, dielectrics constant, paraelectrics</p><p> </p>


2015 ◽  
Vol 2 (2) ◽  
pp. 13-15
Author(s):  
Sugapriya S ◽  
Lakshmi S ◽  
Senthil kumaran C.K ◽  
Chandarshekar B ◽  
Ranjithkumar R

We report in this paper, the structural and I-V properties of ZnO nano needle-like structure synthesized by Co-precipitation method. X-ray diffraction (XRD) result shows that the ZnO nano needle-like structure with hexagonal phase and no secondary phase was observed. The crystallite size has been calculated by Scherrer’s equation which was found to be in the range 40-60 nm. SEM images reveal that ZnO nano needle-like structure has the length of ~5.5 µm and base of ~5 µm are consistent with the results from SEM investigations. I-V characteristics have been carried out to study the conducting behaviour of the prepared ZnO nano needle-like structures.


Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 832
Author(s):  
Edna X. Figueroa-Rosales ◽  
Javier Martínez-Juárez ◽  
Esmeralda García-Díaz ◽  
Daniel Hernández-Cruz ◽  
Sergio A. Sabinas-Hernández ◽  
...  

Hydroxyapatite (HAp) and hydroxyapatite/multi-walled carbon nanotube (MWCNT) composites were obtained by the co-precipitation method, followed by ultrasound-assisted and microwave radiation and thermal treatment at 250 °C. X-ray diffraction (XRD) confirmed the presence of a hexagonal phase in all the samples, while Fourier-transform infrared (FTIR) spectroscopy elucidated the interaction between HAp and MWCNTs. The photoluminescent technique revealed that HAp and the composite with non-functionalized MWCNTs present a blue luminescence, while the composite with functionalized MWCNTs, under UV-vis radiation shows an intense white emission. These findings allowed presentation of a proposal for the use of HAp and HAp with functionalized MWCNTs as potential materials for optoelectronic and medical applications.


2015 ◽  
Vol 827 ◽  
pp. 19-24 ◽  
Author(s):  
Nur Afifah ◽  
Nadia Febiana Djaja ◽  
Rosari Saleh

In this study, the photocatalytic activity of pure Fe- doped ZnO and Fe- doped ZnO/Montmorillonite nanocomposite has been investigated for the degradation of malachite green under UV light irradiation. Both photocatalysts were synthesized using co-precipitation method and characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, Fourier-transform infrared absorption, and electron spin resonance. The results showed that the photocatalytic efficiency is better in the presence of montmorillonite compared to pure Fe- doped ZnO. To detect the possible reactive species involved in degradation of organic dyes control experiments with introducing scavengers into the solution of organic dyes were carried out. It is found that electron plays an important role in the degradation of malachite green.


2011 ◽  
Vol 311-313 ◽  
pp. 1713-1716 ◽  
Author(s):  
Yan Rong Sun ◽  
Tao Fan ◽  
Chang An Wang ◽  
Li Guo Ma ◽  
Feng Liu

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).


2015 ◽  
Vol 645-646 ◽  
pp. 1339-1344 ◽  
Author(s):  
Yan Ting Yin ◽  
Qing Hua Chen ◽  
Ting Ting Yan ◽  
Qing Hua Chen

The objective of this study was to develop a novel silica modified large-sized hydroxyapatite whiskers with improved properties for use in bone repair applications. Large-sized whiskers with a mean length of 250μm were obtained by a hydrothermal co-precipitation method at 150°C, 7.5Mpa in high-pressure reactor. Silica modified hydroxyapatite whiskers were prepared by dissolving TEOS in ethanol solution, then sintering with hydroxyapatite. The compositional and morphological properties of prepared whiskers were studied by means of x-ray diffraction (XRD), Fouier transform infrared (FT-IR), scanning electron microscopy (SEM). The results indicated the evidence of nanosilicon dioxide particles on the surface of HAP whiskers. The size of nanosilicon dioxide particles depends on dropping and stirring rate. Hence, this new type of silica modified large-sized hydroxyapatite whiskers is a valuable candidate for biomedical applications.Key words: hydroxyapatite, hydrothermal co-precipitation, surface modified, whiskers


2020 ◽  
Vol 1 (4) ◽  
pp. 187-193
Author(s):  
Elaheh Gharibshahian

KTiOPO4 nanoparticles are known as the best candidate to utilize for second-harmonic generation in multiphoton microscopes and bio labels. Size and shape are important and effective parameters to control the properties of nanoparticles. In this paper, we will investigate the role of capping agent concentration on the size and shape control of KTP nanoparticles. We synthesized KTP nanoparticles by the co-precipitation method. Polyvinyl alcohol with different mole ratios to titanium ion (1:3, 1:2, 1:1) was used as a capping agent. Products were examined by X-ray diffraction patterns and scanning electron microscopy analyses. X-ray diffraction patterns confirmed the formation of the KTP structure. The biggest (56.36nm) and smallest (39.42nm) grain size were obtained by 1:3 and 1:1 mole ratios of capping agent, respectively. Dumbly, spherical and polyhedral forms of KTP nanoparticles were observed by the change in capping agent mole ratio. The narrowest size distribution of KTiOPO4 nanoparticles was obtained at 1:1 mole ratio of capping agent. Doi: 10.28991/HIJ-2020-01-04-06 Full Text: PDF


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