scholarly journals Effect of Starting Solution on the Formation of Calcium Phosphate Nano Particles by Hydrothermal Process

2004 ◽  
Vol 112 (1312) ◽  
pp. 650-654 ◽  
Author(s):  
Hidemitsu KASAHARA ◽  
Nobuo OGATA ◽  
Takashi OGIHARA
Keyword(s):  
Calcium Phosphate ◽  
Hydrothermal Process ◽  
Nano Particles ◽  
Starting Solution

Fabrication and Characterization of Various Calcium Phosphate Powders by Ultrasonic Spray Pyrolysis Technique

2006 ◽  
Vol 317-318 ◽  
pp. 57-60
Author(s):  
H.J. Wang ◽  
Young Keun Jeong ◽  
Kyung Sik Oh ◽  
B.H. Kim ◽  
Seong Hee Lee ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Calcium Phosphate ◽  
Spray Pyrolysis ◽  
Single Phase ◽  
Spray Pyrolysis Technique ◽  
Calcium Phosphates ◽  
Ultrasonic Spray Pyrolysis ◽  
Ultrasonic Spray Pyrolysis Technique ◽  
Starting Solution ◽  
Ultrasonic Spray

To overcome the difficulty of preparing the stoichiometric single phase calcium phosphate materials, ultrasonic spray pyrolysis was used to fabricate various calcium phosphates. Effect of the initial Ca/P ratios and pyrolysis temperature were investigated in preparation of single phase materials. Also thermal stability of the obtained powders was estimated with the heat treatment in the air. Crystallinity of the powders was analyzed using XRD and FT-IR. The HAp and β-TCP powders with single phase could be obtained from their stoichiometric Ca/P ratios of 1.50 and 1.67, respectively. These single phase powders with good crystallinity and stoichiometry were stable with respect to heat treatment up to 1000oC. The particle size of these powders would be controlled by the concentration of starting solution.

Synthesis and Characterization of Barium Titanate Nano-Powders by the Hydrothermal Process

2006 ◽  
Vol 301 ◽  
pp. 219-222 ◽  
Author(s):  
Kouji Tokita ◽  
Shigeki Sato
Keyword(s):  
Particle Size ◽  
Barium Titanate ◽  
Hydrothermal Process ◽  
Tio2 Particle ◽  
Nano Particles ◽  
Axis Length ◽  
Average Size ◽  
Source Materials ◽  
Perovskite Lattice

Barium titanate (BaTiO3) nano-particles with high crystalinity were synthesized by hydrothermal process using Ba(OH)2·8H2O and TiO2 as source materials. The average size of the synthesized BaTiO3 particles decreased as the TiO2 particle size decreased. The amount of hydroxide ions incorporated into the perovskite lattice decreased as the BaTiO3 particle size increased and then became constant above 50 nm. Moreover, the ratio of the c- to a-axis length increased when the BaTiO3 particle size was above 50 nm. Sintered ceramics with a grain size smaller than 100 nm were obtained by using highly crystallized hydrothermal BaTiO3 particles.

Synthesis and Magnetic Properties of CoFe2O4 Nano-Particles

2010 ◽  
Vol 148-149 ◽  
pp. 998-1002 ◽  
Author(s):  
Xiao Yun Chen ◽  
Hua Li ◽  
Yue Zeng Su ◽  
Zi Shan Huang ◽  
He Zhou Liu
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Magnetic Properties ◽  
Hydrothermal Process ◽  
Nano Particles ◽  
Vibrating Sample Magnetometer ◽  
X Ray ◽  
Transmission Electron ◽  
Structure Morphology ◽  
Water Ratio

Spinel CoFe2O4 nano-particles were synthesized by hydrothermal traditionally and Ethylene Glycol (EG) assisted hydrothermal process originally. The effects of reaction temperatures from 140°C to 200°C, different OH- provider and EG/water ratio on the nano-particles’ structure, morphology and magnetic properties of composition were studied by X-ray diffractometer (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). The possible mechanism for the effects on the properties was also discussed in details. The results showed that NaAC as OH- provider and higher EG/water ratio in solvent were benefit for getting smaller CoFe2O4 nano-particles. And existence of EG is also important to remove the α-Fe2O3 phase.

Dimensionally and morphologically controlled growth of calcium phosphate crystals by an organic-free hydrothermal process

2016 ◽  
Vol 42 (15) ◽  
pp. 17387-17397 ◽  
Author(s):  
Ruijing Li ◽  
Yurong Cai ◽  
Ying Yang ◽  
Shunbin Fang ◽  
Xiuping Su ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Hydrothermal Process ◽  
Controlled Growth

scholarly journals Preparation and Characterization of Zno Nano particles Prepared by Hydrothermal Method

2019 ◽  
Vol 24 (3) ◽  
pp. 91
Author(s):  
Mohammed Ajmi Abd1 ◽  
Khalid Hamdi Razeg1 ◽  
Raad M.S Al-haddad2
Keyword(s):  
Quantum Confinement Effect ◽  
Hydrothermal Process ◽  
Blue Shift ◽  
Band Gap Energy ◽  
Zinc Nitrate ◽  
Nano Particles ◽  
Surface Topology ◽  
Nitrate Hexahydrate ◽  
X Ray Diffraction ◽  
Afm Analysis

In this study,the nanoparticles of zinc oxide were readily prepared  through Hydrothermal process by using zinc nitrate hexahydrate, and Sodium hydroxide as aprecursors. The surface topology, and crystalline structure of prepared ZnO nanoparticles were studied. X-ray diffraction (XRD) revealed that the prepared ZnO nano particles is highly crystalline, having (wurtzite) crystal structure.  The optical analysis by UV–vis showed that these ZnO nano particles have considerable blue shift in the optical band gap energy (Eg = 4.9eV), and this may be to the  quantum confinement effect of nano particles. The FT-IR results shows the  existence of OH, COO, H2O groups the characteristic vibrational modes of Zn–O were identified. and AFM analysis showed that the diameters of the ZnO particles is in ananometer range of (70-74)nm.   http://dx.doi.org/10.25130/tjps.24.2019.052 

scholarly journals Calcium Phosphate Powder Synthesized from Calcium Acetate and Ammonium Hydrophosphate for Bioceramics Application

Ceramics ◽  
2018 ◽  
Vol 1 (2) ◽  
pp. 375-392 ◽  
Author(s):  
Tatiana Safronova ◽  
Valery Putlayev ◽  
Yaroslav Filippov ◽  
Tatiana Shatalova ◽  
Evgeny Karpushkin ◽  
...  
Keyword(s):  
Phase Composition ◽  
Calcium Phosphate ◽  
Room Temperature ◽  
Calcium Acetate ◽  
Molar Ratio ◽  
Composite Ceramics ◽  
Phosphate Powder ◽  
Starting Solution ◽  
By Products ◽  
Ammonium Hydrophosphate

Calcium phosphate powder was synthesized at room temperature from aqueous solutions of ammonium hydrophosphate and calcium acetate without pH adjusting at constant Ca/P molar ratio 1.5. Phase composition of the as-synthesized powder depended on the precursors concentration: At 2.0 M of calcium acetate in the starting solution, poorly crystallized hydroxyapatite was formed, 0.125 M solution of calcium acetate afforded brushite, and the powders synthesized from 0.25–1.0 M calcium acetate solutions were mixtures of the mentioned phases. Firing at 1100 °C led to complete elimination of the reaction by-products, yet the phase composition of the annealed compacted samples was the following: When 2.0 M solution of calcium acetate was used, the obtained ceramics consisted of β-Ca3(PO4)2, whereas at 0.125 to 1.0 M of calcium acetate, the ceramics was a mixture of β-Ca3(PO4)2 and β-Ca2P2O7. Synthesized calcium phosphate powders can be used as the powdered precursors for biocompatible bioresorbable composite ceramics production.

Hydrothermal Synthesis of Hydroxyapatite and Pollucite from Calcium Phosphate

1994 ◽  
Vol 353 ◽  
Author(s):  
Masaaki Kaneko ◽  
Yuichi Shoji ◽  
Hiroyuki Matsuura ◽  
Nakamichi Yamasaki
Keyword(s):  
Hydrothermal Synthesis ◽  
Calcium Phosphate ◽  
Hydrothermal Process ◽  
Stable Form ◽  
Mixing Ratios

AbstractHydroxyapatite (HAP : Ca10(PO4 ) 6 (OH) 2 ) and aluminosili-cate were easily synthesized using a hydrothermal process with mixing ratios of Ca/P=1.67 (Ca(PO3)2 and Ca(OH)2) and Si/Al=4 (SiO2 and Al(OH)3). The temperature was kept constant at 573 K for 60 minutes. .Cesium (Cs) and Cerium (Ce) contained in Ca(PO3)2 , were found to take on a stable form in the pollucite (CsAlSi2O6) structure and the monazite (CePO4) structure.

Hydrothermal Synthesis and Magnetic Properties of α-Fe2O3 Polyhedrons

2011 ◽  
Vol 233-235 ◽  
pp. 3014-3017
Author(s):  
Li Tian ◽  
Ke Long Huang
Keyword(s):  
Magnetic Properties ◽  
Hydrothermal Process ◽  
Average Diameter ◽  
Ferromagnetic Behavior ◽  
X Ray Diffraction ◽  
One Pot ◽  
X Ray ◽  
Starting Solution ◽  
Experimental Parameters ◽  
Topotactic Transformation

α-Fe2O3polyhedrons have been successfully synthesized via a one-pot hydrothermal process. The average diameter of the synthesized α-Fe2O3polyhedrons is about 0.8 μm. The structure and morphology of α-Fe2O3polyhedrons were characterized by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. And the possible formation mechanism is proposed that the α-Fe2O3polyhedrons are grown epitaxially from the FeOOH precursors by topotactic transformation. The experimental parameters play a crucial role in the growth of the α-Fe2O3polyhedrons. The results indicate that the phase and morphology of the products are greatly affected by the concentrations of disodium ethyleediamine tetracetate and NaOH in the starting solution. The magnetic properties of α-Fe2O3polyhedrons show weak ferromagnetic behavior with the saturation magnetization of 0.498 emu/g, remanent magnetization of 0.051 emu/g and coercivity of 372.81 Oe.

Effect of Zinc, Copper and Calcium Phosphate Nano Particles on Growth of Spirulina platensis

2014 ◽  
Vol 37 (3) ◽  
pp. 207-212 ◽  
Author(s):  
Tapan Adhikari ◽  
S. Kundu ◽  
Ajay A. K. Biswas ◽  
J. C. Tarafdar ◽  
A. Subba Rao
Keyword(s):  
Calcium Phosphate ◽  
Spirulina Platensis ◽  
Nano Particles
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