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.

Preparation of Silver-Containing Hydroxyapatite Powder by Ultrasonic Spray-Pyrolysis Technique and its Antibacterial Property

2011 ◽  
Vol 493-494 ◽  
pp. 678-683 ◽  
Author(s):  
Yusuke Kawanobe ◽  
Michiyo Honda ◽  
Toshiisa Konishi ◽  
Minori Mizumoto ◽  
Yuri Habuto ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Spray Pyrolysis ◽  
Single Phase ◽  
Spray Pyrolysis Technique ◽  
Ultrasonic Spray Pyrolysis ◽  
Spherical Particles ◽  
Nominal Composition ◽  
Ultrasonic Spray Pyrolysis Technique ◽  
Ultrasonic Spray ◽  
Starting Solutions

We prepared silver-containing hydroxyapatite (Ag-HAp) powders by an ultrasonic spray-pyrolysis (USSP) technique and evaluated their antibacterial activity.　　Ag-HAp powders with Ag contents of 0, 1, 2, 5, and 20 mol% as nominal composition were prepared by the above USSP technique. The droplets of starting solutions were dried at 300 °C and then pyrolyzed at 850 °C to prepare the Ag-HAp powders. Ag-HAp powders showed a HAp single phase and were composed of spherical particles with a diameter of 0.5 - 3.0 μm. To evaluate the antibacterial activity of resulting powders, colony count method was performed using Staphylococcus aureus. Ag-HAp powders with the contents of Ag more than 5 mol% showed good antibacterial activity.

Effect of the Concentrations of the Starting Solution on the Syntheses and Powder Properties of Hollow Tricalcium-Phosphate Microspheres by Ultrasonic Spray-Pyrolysis Technique

2006 ◽  
Vol 309-311 ◽  
pp. 235-238 ◽  
Author(s):  
Toshiki Ohno ◽  
Mamoru Aizawa
Keyword(s):  
Spray Pyrolysis ◽  
Tricalcium Phosphate ◽  
Spray Pyrolysis Technique ◽  
Ultrasonic Spray Pyrolysis ◽  
Sintered Compact ◽  
Molar Ratios ◽  
Ultrasonic Spray Pyrolysis Technique ◽  
Starting Solution ◽  
Ultrasonic Spray ◽  
Powder Properties

We synthesized tricalcium phosphate (TCP) microspheres using an ultrasonic spray-pyrolysis technique, and investigated the effect of the concentrations of the starting solution on the powder properties. The XRD pattern showed that the crystalline phases of the resulting powders were β-TCP/HAp biphase in the case of pyrolysis temperature at 850 °C and TCP single phase at 1000 °C. The Ca/P molar ratios were determined by XRF to be at 1.50±0.03. The particle shapes of the powders were observed by SEM; the diameters of the microspheres were narrowly distributed from 0.5 to 4 µm. The mean particle diameters of the resulting powder increased with the concentration of the starting solutions and could be controlled in the range of 0.85-1.4 µm. When the compressed powder was sintered at 1050 °C for 5 h , the relative density of the sintered compact attained to 97%. The TCP microspheres had good sinterability.

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