scholarly journals Synthesis of nano-sized β-tricalcium phosphate via wet precipitation

2011 ◽  
Vol 5 (4) ◽  
pp. 193-198 ◽  
Author(s):  
Bahman Mirhadi ◽  
Behzad Mehdikhani ◽  
Nayereh Askari

Nano-size ?-tricalcium phosphate powders with average grain size of 50 nm were prepared by the wet chemical precipitation method with calcium nitrate and diammonium hydrogen phosphate as calcium and phosphorus precursors, respectively. The pH of the system was maintained at 8 and 10.8 by adding of sodium hydroxide. Filtered cake was dried at 80?C and calcined at 700?C. The dried and calcined powders were characterized using X-ray diffractrometry (XRD), Fourier transform infrared spectroscopy (FTIR), inductively coupled plasma atomic emission spectroscopy (ICPAES) and scanning electron microscopy (SEM).

2014 ◽  
Vol 46 (2) ◽  
pp. 185-193 ◽  
Author(s):  
B. Mirhadi

A nano sized beta tricalcium phosphate (?-TCP) powder was conventional sintered (CS) and microwave sintered (MW), in order to obtain dense ?-TCP ceramics. In this work the effect of microwave sintering conditions on the microstructure, phase composition and mechanical properties of materials based on tricalcium phosphate (TCP) was investigated by SEM (scanning electron microscopy)and XRD(X-ray diffraction) and then compared with conventional sintered samples. Nano-size ?-TCP powders with average grain size of 80 nm were prepared by the wet chemical precipitation method with calcium nitrate and diammonium hydrogen phosphate as calcium and phosphorus precursors, respectively. The precipitation process employed was also found to be suitable for the production of submicrometre ?-TCP powder in situ. The ?-TCP samples microwave (MW) sintered for 15 min at 1100?C, with average grain size of 3?m, showed better densification, higher density and certainly higher hardness than samples conventionally sintered for 2 h at the same temperature. By comparing sintered and MW sintered ?-TCP samples, it was concluded that MW sintered ?-TCP samples have superior mechanical properties.


Author(s):  
Behzad Mehdikhani ◽  
Gholam Hossein Borhani

Nano-size β-tricalcium phosphate powders with average grain size of 80 nm were prepared by the wet chemical precipitation method with calcium nitrate and di-ammonium hydrogen phosphate as calcium and phosphorus precursors, respectively. The precipitation process employed was also found to be suitable for the production of sub-micrometre β-TCP powder in situ. The sinterability of the nano-size powders, and the microstructure, mechanical strength of the prepared β-TCP bioceramics were investigated. Bioceramic sample characterization was achieved by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), and density measurements. Powders compacted and sintered at 800, 900, 1000 and 1100 °C showed an increase in relative density from 70 % to 93 %. The results revealed that the maximum hardness of 240 H was obtained for β-TCP sintered at 1100 °C.


Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 250 ◽  
Author(s):  
Francesco Baldassarre ◽  
Angela Altomare ◽  
Nicola Corriero ◽  
Ernesto Mesto ◽  
Maria Lacalamita ◽  
...  

Europium-doped hydroxyapatite Ca10(PO4)6(OH)2 (3% mol) powders were synthesized by an optimized chemical precipitation method at 25 °C, followed by drying at 120 °C and calcination at 450 °C and 900 °C. The obtained nanosized crystallite samples were investigated by means of a combination of inductively coupled plasma (ICP) spectroscopy, powder X-ray diffraction (PXRD), Fourier Transform Infrared (FTIR), Raman and photoluminescence (PL) spectroscopies. The Rietveld refinement in the hexagonal P63/m space group showed europium ordered at the Ca2 site at high temperature (900 °C), and at the Ca1 site for lower temperatures (120 °C and 450 °C). FTIR and Raman spectra showed slight band shifts and minor modifications of the (PO4) bands with increasing annealing temperature. PL spectra and decay curves revealed significant luminescence emission for the phase obtained at 900 °C and highlighted the migration of Eu from the Ca1 to Ca2 site as a result of increasing calcinating temperature.


2013 ◽  
Vol 777 ◽  
pp. 15-18 ◽  
Author(s):  
Jiu Xu Liu ◽  
Feng Wang ◽  
Jian Xing Shen ◽  
Qi Hui Lai ◽  
Ying Gai

nanohydroxyapatite (nanoHA) powders were prepared by liquid phase precipitation method, using diammonium hydrogen phosphate and calcium nitrate tetrahydrate as raw materials. It was studied that the prepared nanoHA powders not sintered and sintered at 800°C to adsorption of Cu2+ and Pb2+ in aqueous solutions, respectively. The structure and size of nanoHA powders was investigated by X-ray diffraction (XRD) and the concentrations of Cu2+and Pb2+ in aqueous solutions were tested by inductively coupled plasma emission spectrometer. The results revealed that the nanoHA powders have obvious absorption function for Cu2+ and Pb2+ in aqueous solutions. In addition, the absorption ratio was affected by the size of nanoHA.


2020 ◽  
Vol 10 (6) ◽  
pp. 6837-6845

β-tricalcium phosphate (β-TCP) is a bioceramic with unique osteoinductive and osteoconductive properties. It can be obtained by calcining calcium-deficient apatites (CDHA) at 750°C and above. The reduction of calcining temperature or the stabilization of the β phase, by doping, is therefore of particular interest. This paper investigates the preparation of CDHA with a theoretical 0.05 Mg/(Ca + Mg) ratio and (Ca+Mg)/P = 1.55 via precipitation method, and the resultant powder is calcined at a different temperature ranging from 80 to 715°C. The as-synthesized undoped powder was used as the reference in this study. The effect of calcination temperature and composition were investigated by the aid of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), inductively coupled plasma optical emission spectroscopy (ICP-OES) and scanning electron microscopy (SEM). The study indicated that the powder was pure Mg-doped beta-tricalcium phosphate. The incorporation of Mg within the calcium phosphate lattice promoted the formation and stabilization of the β -TCP phase at a lower temperature.


Author(s):  
Behzad Mehdikhani ◽  
Bahman Mirhadi

In this study, dense, fine-grained biphasic calcium phosphate bioceramics were designed via sintering method. nanosize hydroxyapatite / β-tricalcium (HA/β-TCP) phosphate powders with average grain size of 80 nm were prepared by the wet chemical precipitation method with calcium nitrate and di-ammonium hydrogen phosphate as calcium and phosphorus precursors, respectively. The precipitation process employed was also found to be suitable for the production of sub-micrometre HA/β-TCP powder in situ. The sinterability of the nanosize powders, and the microstructure, mechanical strength of the prepared HA/β-TCP bioceramics were investigated. Bioceramic sample characterization was achieved by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), and density measurements. Powders compacted and sintered at 800, 900, 1000 and 1100°C showed an increase in relative density from 57% to 93%. The results revealed that the maximum hardness of 229 HVwas obtained for HA/β-TCP sintered at 1100°C.


2021 ◽  
Vol 947 (1) ◽  
pp. 012026
Author(s):  
Trung Dang-Bao ◽  
Hoa-Hung Lam ◽  
Thi-Hoai-Linh Dang

Abstract In the present work, Ce-Ti and Ce-Ti/Fe3O4 hybrid oxides were prepared by co-precipitation method and then characterized by X-ray diffraction (XRD), inductively coupled plasma atomic emission spectroscopy (ICP-AES) and scanning electron microscope (SEM) techniques. The nano-adsorbents were applied to remove fluoride (with the concentration range of 10–30 mg L−1) from aqueous solution, reaching the adsorption equilibrium within 30–60 minutes. Practically, the fluoride removal onto both nanomaterials was efficient at the neutral pH (pH 5–7) and obeyed the Langmuir adsorption isotherm with the maximum adsorption capacities of 22.78 mg g–1 (Ce-Ti) and 20.28 mg g–1 (Ce-Ti/Fe3O4) at room temperature.


2011 ◽  
Vol 239-242 ◽  
pp. 2488-2491
Author(s):  
Hui Juan Ren ◽  
De Hui Sun ◽  
Zhen Feng Cui ◽  
Guang Yan Hong

The europium(III)-benzoic acid(HL)-1,10-phenanthroline(phen) complex was synthesized in the ethanol-H2O system by a precipitation method. The morphology of the minicrystal complex with diameters of ca. 1.0 µm is characterized by scanning electron microscopy (SEM). Elemental analysis and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) are used to determine the chemical composition of the complex. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction analysis (XRD) are used to examine the structure of the complex. The results show that the complex is a new kind of crystalline complex and the composition of the complex is speculated to be EuL3(phen). The thermogravimetric curve (TGA) analysis indicates that the complex is stable below 232 °C in air. The photoluminescence analyses (PLA) exhibit that the complex emits the characteristic red fluorescence of Eu (III) ions at 613nm under ultraviolet light excitation.


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