scholarly journals Investigation of EDTA concentration on the size of carbonated flowerlike hydroxyapatite microspheres

2021 ◽  
Vol 8 (3) ◽  
Author(s):  
Shengkun Yao ◽  
Mei-li Qi ◽  
Liang Qi ◽  
Yongling Ding ◽  
Min Chen ◽  
...  

Ethylenediamine tetraacetic acid (EDTA) is considered an effective crystal growth modifier for template-assisted hydrothermal synthesis of hydroxyapatite (HA) materials. In this work, flowerlike-carbonated HA (CHA) microspheres were synthesized using EDTA via a one-step hydrothermal route. The phase, functional groups, morphology and particle size distribution of the products were examined by X-ray diffraction, Fourier transform infrared spectrometer, field emission scanning electron microscopy as well as laser diffraction particle size analysis. Results show that the morphology of the products can be well controlled by adjusting the EDTA concentration. With an increase of the EDTA concentration, the particle size of flowerlike microspheres decreased from tens of microns down to a few microns. The underlying mechanism for the morphological transition of CHA microspheres with different concentrations of EDTA under hydrothermal conditions is proposed. This work provides a simple way to controllably fabricate CHA microspheres with various sizes using the same synthesis system for biomedical applications, such as cell carriers and drug delivery.

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 232
Author(s):  
Pedro J. Sánchez-Soto ◽  
Eduardo Garzón ◽  
Luis Pérez-Villarejo ◽  
George N. Angelopoulos ◽  
Dolores Eliche-Quesada

In this work, an examination of mining wastes of an albite deposit in south Spain was carried out using X-ray Fluorescence (XRF), X-ray diffraction (XRD), particle size analysis, thermo-dilatometry and Differential Thermal Analysis (DTA) and Thermogravimetric (TG) analysis, followed by the determination of the main ceramic properties. The albite content in two selected samples was high (65–40 wt. %), accompanied by quartz (25–40 wt. %) and other minor minerals identified by XRD, mainly kaolinite, in agreement with the high content of silica and alumina determined by XRF. The content of Na2O was in the range 5.44–3.09 wt. %, being associated with albite. The iron content was very low (<0.75 wt. %). The kaolinite content in the waste was estimated from ~8 to 32 wt. %. The particle size analysis indicated values of 11–31 wt. % of particles <63 µm. The ceramic properties of fired samples (1000–1350 °C) showed progressive shrinkage by the thermal effect, with water absorption and open porosity almost at zero at 1200–1250 °C. At 1200 °C, the bulk density reached a maximum value of 2.38 g/cm3. An abrupt change in the phase evolution by XRD was found from 1150 to 1200 °C, with the disappearance of albite by melting in accordance with the predictions of the phase diagram SiO2-Al2O3-Na2O and the system albite-quartz. These fired materials contained as main crystalline phases quartz and mullite. Quartz was present in the raw samples and mullite was formed by decomposition of kaolinite. The observation of mullite forming needle-shape crystals was revealed by Scanning Electron Microscopy (SEM). The formation of fully densified and vitrified mullite materials by firing treatments was demonstrated.


Author(s):  
Fredy Kurniawan ◽  
Rahmi Rahmi

SnO2 nanoparticles have been synthesized by high voltage electrolysis. Tin bare was used for anode and cathode. The effect of potentials and electrolyte were studied. The particles obtained after electrolysis was characterized using X-ray Diffraction (XRD). The diffractogram is in agreement with the standard diffraction pattern of SnO2 which is identified as tetragonal structure. The Fourier Transform Infrared (FTIR) spectrum indicates that there is a vibration of Sn–O asymmetric at 580 cm-1. The optimum potential for SnO2 nanoparticles synthesis is 60 V at 0.06 M HCl which shows the highest UV-Vis spectrum. The absorption peak of SnO2 nanoparticles by UV-Vis spectrophotometer appears at about 207 nm. The particle size analysis shows that the SnO2 nanoparticles obtained have the size distribution in a range of 25-150 nm with the highest volume at 83.11 nm. Copyright © 2017 BCREC Group. All rights reservedReceived: 15th November 2016; Revised: 26th February 2017; Accepted: 27th February 2017How to Cite: Rahmi, R., Kurniawan, F. (2017). Synthesis of SnO2 Nanoparticles by High Potential Electrolysis. Bulletin of Chemical Reaction Engineering & Catalysis, 12 (2): 281-286 (doi:10.9767/bcrec.12.2.773.281-286)Permalink/DOI: http://dx.doi.org/10.9767/bcrec.12.2.773.281-286 


1989 ◽  
Vol 169 ◽  
Author(s):  
Rollin E. Lakis ◽  
Sidney R. Butler

AbstractY1Ba2Cu3O7 has been prepared by the evaporative decomposition of solutions method. Nitrate and mixed anion solutions were atomized and decomposed at temperatures ranging from 300°C to 950°C. The resulting materials have been characterized using x-ray powder diffraction, Thermal Gravimetric Analysis (TGA), particle size analysis, Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM). The powder consists of 0.3 micron agglomerated hollow spheres with a primary particle size of 0.06 micron. TGA and x-ray diffraction indicate the presence of barium nitrate and barium carbonate due to incomplete decomposition and/or product contamination by the process environment.


2015 ◽  
Vol 1087 ◽  
pp. 142-146 ◽  
Author(s):  
Rosli Asmawi ◽  
Mohd Halim Irwan Ibrahim ◽  
Azriszul Mohd Amin ◽  
Najwa Mustapha ◽  
Iis Sopyan

Nanocrystalline hydroxyapatite (HA) powder was synthesized by a simple heating process involving simple chemical reaction. The characterization of the produced powder showed that the powder is nanosize with particle in the range of 30-70 mm in diameter and almost evenly spherical in shape. The powder also has a high surface area of 43.16 m2/g. Field Emission Scanning Electron Microscopy (FESEM) observation showed the crystallite and particle size become bigger with an increment of calcination temperature, indicating increasing of crystallinity.. FESEM observation showed the particle size become bigger with an increment of calcinations temperature. It is in agreement with the crystallite size analysis, obtained by Scherer’s formula and particle size analysis, measured by nanoSizer. X-ray Diffraction (XRD) and Fourier Transform Infra Red Spectroscopy (FTIR) analyses exhibited the same result, where HA phase was clearly observed at at various temperatures up to 600 ̊C. However, at temperature more than 600 ̊C, Tri calcium phosphate (TCP) phase appeared suppressing the HA phase, producing biphasic calcium phosphate.


2015 ◽  
Vol 1109 ◽  
pp. 314-318
Author(s):  
Nor Diyana Abdul Aziz ◽  
Kelimah Elong ◽  
Norlida Kamarulzaman

Tin Oxide (SnO2) is a metal oxide which has many applications in industry. In this study, SnO2 powders were synthesized by a self-propagating combustion (SPC) method. The product was annealed at 800 °C for 12 and 24 h before characterizing with X-Ray Diffraction (XRD) for phase studies. X-Ray Diffraction results showed that both samples are pure of tetragonal structure with space group P42/mnm. The sample annealed at a longer period, that is, 24 h, shows a higher degree of crystallinity compared to the 12 h annealed sample. It also shows a smaller full width at half maximum (FWHM), indicating larger crystallite size for the 24 h annealed sample. The particle size analysis reveals that there are two groups of particle size distributions for both samples. SEM results give values that are different from the particle sizer results due to the different nature of the measurement methods.


2020 ◽  
Vol 860 ◽  
pp. 128-134
Author(s):  
Cahyaning Fajar Kresna Murti ◽  
Malik Anjelh Baqiya ◽  
Endarko ◽  
Triwikantoro

Particle size analysis of synthesized Al2O3 by dissolution and alkali fusion-coprecipitation methods has been conducted. The formation of nano- or microparticles can be synthesized by the top-down (physically) and bottom-up (chemically) methods. In this study, the commercial alumina (Merck) with the particle size of 63 µm was synthesized through the bottom-up method. The dissolution method was done by reacting to alumina with ammonium hydroxide (NH4OH). The alkali fusion method was carried out by reacting alumina with sodium hydroxide (NaOH) and it obtained by coprecipitation of the alkali fusion product with HCl and NH4OH. The result from both methods were calcined at 600°C. The phase of synthesized Al2O3 was identified by using X-ray diffraction (XRD), whereas the morphology observed using a transmission electron microscope (TEM), and the particle sizes measured by particle sizes analyzer (PSA). The XRD pattern shows the γ-Al2O3 phases with particle sizes of ~33 nm and ~25 nm from TEM observations, while the PSA results revealed agglomerated particles with particle sizes of 1263 nm and 477 nm for the dissolution and alkali fusion-coprecipitation method, respectively. Therefore, both methods can be used to reduce the particle size of γ-Al2O3.


Clay Minerals ◽  
2009 ◽  
Vol 44 (3) ◽  
pp. 311-317 ◽  
Author(s):  
J. Bonifacio-Martínez ◽  
J. Serrano-Gómez ◽  
Ma. Del Carmen López-Reyes ◽  
F. Granados-Correa

AbstractThe effects of mechano-chemical treatment on the surface characteristics and sorption properties of hydrotalcite were studied. Non-milled (crushed) and milled samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), particle size analysis and specific area. A milling time of 2 h decreased the particle size of the hydrotalcite samples from 21 to 8.0 nm, the specific area from 97 to 5.7 m2 g–1 and the total pore volume from 0.41 to 0.01 cm3. After the crushed and milled samples had been separately calcined at 500ºC, they were agitated with 10–2 M Na2MoO4 aqueous solutions for 48 h. The molybdate ion content in the regenerated non-milled hydrotalcite samples (HTc-MoO4) was found to be 6.0 meq g–1 while in the milled hydrotalcite (HTm-MoO4) samples this content was 2.5 meq g–1. The lower molybdate content was thought to be a result of compaction and, hence, reduced reactivity of the milled HT samples.


2011 ◽  
Vol 412 ◽  
pp. 25-31
Author(s):  
Wen Yuan Gao ◽  
Xing Xin Jia ◽  
Mei Hong Niu ◽  
Nai Ling Tang ◽  
Zhi Qiang Hu

The nanosized TiO2 is prepared by micro-emulsion process in the system of cyclohexane / [Span80 combined with OP-10] / water with TiCl4 as raw material. The selection method of the surface-active agents was investigated and the influence of amount of surfactant, water / oil ratio and concentration of reactants on the particle size were discussed in this work. The temperature schedule, crystal structure, particle size distribution and appearance of the nanocrystalline TiO2 were analyzed by differential thermal analysis (DTA) combined with X-ray diffraction (XRD), laser particle size analysis (LPSA) and scanning electron microscope (SEM). The results showed that: under these conditions of mixture of 8g Span80 and 2g OP-10 as the emulsifier, water / oil mass ratio of 1/4, TiCl4 concentration of 0.6mol / L and calcinations temperature of 510°C, nanoTiO2 powder with smaller particle size and better dispersion was prepared . And the average size of the product was 27.3nm.


2013 ◽  
Vol 1 (1) ◽  
pp. 11-14
Author(s):  
N. Sahu ◽  
◽  
R. K. Duchaniya ◽  

The ZnO-CdO nanocomposite was prepared by sol-gel method by using their respective nitrates. It is a simple and low cost method to prepare nanocomposites. The drying temperature and drying period of prepared gel was varied during the synthesis process. The prepared samples were characterized by using scanning electron microscope (SEM), particle size analysis (PSA), X-ray diffraction (XRD) and photoluminescence spectroscopy (PL) to get surface morphology, idea of getting particle of nanosized range so that further characterizations can be done, to study the optical property of synthesized nanocomposite and measure the band gap . The grain size determined by Scherrer’s formula was found to be between 30-50 nm.


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