Scale-Up of Wet Precipitation Calcium Phosphate Synthesis

2014 ◽  
Vol 604 ◽  
pp. 216-219 ◽  
Author(s):  
Marina Sokolova ◽  
Andris Putnins ◽  
Imants Kreicbergs ◽  
Janis Locs
Keyword(s):  
Calcium Phosphates ◽  
Scale Up ◽  
Chemical Precipitation ◽  
Pilot Scale ◽  
Precipitation Method ◽  
Technological Parameters ◽  
Wet Chemical ◽  
Pilot Scale Reactor ◽  
Scale Reactor ◽  
Wet Chemical Precipitation

Within current research calcium phosphates were synthesized by wet chemical precipitation method in laboratory and pilot scale reactor. The aim of this work was to study the influence of main technological parameters of wet chemical precipitation synthesis and scale-up of laboratory synthesis. The results showed that it is possible to obtain calcium phosphates with different and reproducible phase compositions such as hydroxyapatite (HAp), β-tricalcium phosphate (β-TCP) and biphasic calcium phosphates (HAp/β-TCP) in pilot scale reactor. Using the method developed it was possible to increase the product yield more than 30 times compared to formerly used laboratory scale method.

scholarly journals Calcium phosphate bioceramics prepared from wet chemically precipitated powders

2010 ◽  
Vol 4 (1) ◽  
pp. 45-51 ◽  
Author(s):  
Kristine Salma ◽  
Liga Berzina-Cimdina ◽  
Natalija Borodajenko
Keyword(s):  
Calcium Phosphate ◽  
Thermal Treatment ◽  
Calcium Hydroxide ◽  
Calcium Phosphates ◽  
Chemical Precipitation ◽  
Synthesis Temperature ◽  
Synthesis Product ◽  
Technological Parameters ◽  
Wet Chemical ◽  
Wet Chemical Precipitation

In this work calcium phosphates were synthesized by modified wet chemical precipitation route. Contrary to the conventional chemical precipitation route calcium hydroxide was homogenized with planetary mill. Milling calcium oxide and water in planetary ball mill as a first step of synthesis provides a highly dispersed calcium hydroxide suspension. The aim of this work was to study the influence of main processing parameters of wet chemical precipitation synthesis product and to control the morphology, phase and functional group composition and, consequently, thermal stability and microstructure of calcium phosphate bioceramics after thermal treatment. The results showed that it is possible to obtain calcium phosphates with different and reproducible phase compositions after thermal processing (hydroxyapatite [HAp], ?-tricalcium phosphate [?-TCP] and HAp/?-TCP) by modified wet-chemical precipitation route. The ?-TCP phase content in sintered bioceramics samples is found to be highly dependent on the changes in technological parameters and it can be controlled with ending pH, synthesis temperature and thermal treatment. Pure, crystalline and highly thermally stable (up to 1300?C) HAp bioceramics with homogenous grainy microstructure, grain size up to 200-250 nm and high open porosity can be successfully obtained by powder synthesized at elevated synthesis temperature of 70?C and stabilizing ending pH at 9. .

Nanostructured Calcium Phosphates for Biomedical Applications

2014 ◽  
Vol 604 ◽  
pp. 212-215 ◽  
Author(s):  
Linda Vecbiskena ◽  
Luigi de Nardo ◽  
Roberto Chiesa
Keyword(s):  
Phase Transformation ◽  
Biomedical Applications ◽  
Calcium Phosphates ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Dihydrogen Phosphate ◽  
Ammonium Dihydrogen Phosphate ◽  
Wet Chemical ◽  
Wet Chemical Precipitation

This work is focused on the phase transformation from amorphous calcium phosphate (ACP) to nanostructured hydroxyapatite (HA) or tricalcium phosphate (TCP). Amorphous calcium phosphates with Ca/P molar ratio near 1.67 and 1.5 were synthesized by wet-chemical precipitation method and treated with ethanol. Upon thermal treatment, ACP clusters about 50 nm create a nanostructured HA or TCP. The highlights of this research: The precipitate treatment with ethanol provided a pure α-TCP that was found to be stable up to 1000 °C. HA is obtained from the ACP precursor synthesized using also ammonium dihydrogen phosphate.

Synthesis and Structural Characterization of Zinc and Magnesium Doped Hydroxyapatite

2012 ◽  
Vol 531-532 ◽  
pp. 250-253 ◽  
Author(s):  
Hong Quan Zhang ◽  
Ming Zhang ◽  
Lu Wei Fu ◽  
Yu Ning Cheng
Keyword(s):  
Hydrothermal Treatment ◽  
Structural Characterization ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
Starting Solution ◽  
Wet Chemical ◽  
Zn Ions ◽  
Wet Chemical Precipitation ◽  
Surface Of Crystals

Zn or Mg ions doped hydroxyapatite (HA) particles were successfully developed by introducing various concentration of Zn or Mg in the starting solution using wet chemical precipitation method and followed a hydrothermal treatment. The products were identified as HA by XRD and FTIR, and the precipitated particles had a rod-like morphology. All the products for Mg and Zn ions concentration in the preparation solution less than 40 mol% were identified as HA. Substitution of Mg and Zn in HA crystal would impair the crystallization of HA and significantly reduce the length of a, c values of HA unit cell, which clearly demonstrated that Mg or Zn ions were structurally incorporated into the apatite crystals, they were not just absorbed on the surface of crystals.

scholarly journals Far-infrared optical constants of ZnO and ZnO/Ag nanostructures

RSC Advances ◽  
2014 ◽  
Vol 4 (40) ◽  
pp. 20902-20908 ◽  
Author(s):  
Reza Zamiri ◽  
Avito Rebelo ◽  
Golriz Zamiri ◽  
Atena Adnani ◽  
Ajay Kuashal ◽  
...  
Keyword(s):  
Optical Constants ◽  
Far Infrared ◽  
Cost Effective ◽  
Chemical Precipitation ◽  
Chemical Precipitation Method ◽  
Precipitation Method ◽  
Ag Nanoparticle ◽  
Wet Chemical ◽  
Wet Chemical Precipitation

We report on the synthesis of ZnO nanoplates and ZnO nanoplate/Ag nanoparticle heterostructures via a simple and cost effective wet chemical precipitation method.

Preparation of F-Doped Hydroxyapatite via Wet-Chemical Precipitation Technique Combined with pH-Cycling

2015 ◽  
Vol 1117 ◽  
pp. 205-208
Author(s):  
V. Zalite ◽  
Karina Kostrjukova ◽  
Janis Locs
Keyword(s):  
Chemical Precipitation ◽  
Infrared Spectrometry ◽  
Technological Parameters ◽  
Substitution Level ◽  
Vis Spectroscopy ◽  
Ph Cycling ◽  
Ft Ir ◽  
Wet Chemical ◽  
Wet Chemical Precipitation

F-doped hydroxyapatite (FHAp, Ca10(PO4)6OH2-xF2x) was synthesized by two step technology – wet-chemical precipitation and pH-cycling. Obtained powders were dried and calcined for further characterization. FHAp were analyzed by Fourier transform infrared spectrometry (FT-IR), scanning electron microscopy (SEM) and UV-VIS spectrophotometry. FT-IR analysis approved fluoride incorporation into HAp structure, confirmed by OH...F bonding at 3546 and 745 cm-1. SEM microphotographs showed, that as-synthesized FHAp precipitates consist of needle-like crystallites. UV-VIS spectroscopy results were used for the determination of actual F- substitution level. After evaluation of results it was concluded, that fluoride substitution level in FHAp structure reached only x≤0.6. To perform higher substitution level, the technological parameters of the process need to be optimized.

Evaluation of Sr- and/or Mg-Containing Hydroxyapatite Behavior in Simulated Body Fluid

2014 ◽  
Vol 631 ◽  
pp. 61-66 ◽  
Author(s):  
Liga Stipniece ◽  
Kristine Salma-Ancane ◽  
Andris Putnins ◽  
Liga Berzina-Cimdina
Keyword(s):  
Simulated Body Fluid ◽  
Body Fluid ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
Apatite Formation ◽  
Particle Sizes ◽  
Chemical Phase ◽  
Ca Ions ◽  
Wet Chemical ◽  
Wet Chemical Precipitation

The main goal of this study was to evaluate the behavior of Sr- and/or Mg-containing hydroxyapatite (HAp) bioceramics in simulated body fluid (SBF). Sr-and/or Mg-containing HAp powders were synthesized by modified wet chemical precipitation method. Sr-and/or Mg-containing HAp bioceramics were prepared by uniaxial pressing of the precipitated powders and subsequent sintering at 1100 °C for 1 h. The synthesis products were characterized in terms of chemical, phase and molecular composition. Influence of the substitutions on thermal stability, morphology and microstructure of the HAp products were evaluated. Results suggest that incorporation of Sr (up to 1.45 wt.%) in HAp structure induced an increasing of particle sizes, but incorporation of Mg (up to 1.05 wt.%) led to a reduction of particle sizes of the HAp powders. The ability to simultaneously release bioactive ions and the apatite-formation ability of the Sr-and/or Mg-containing HAp bioceramics were evaluated through immersing the samples in SBF for different time periods. Ca ions release and apatite-formation ability on the surfaces of the Sr-and/or Mg-containing HAp bioceramics in SBF depends on Sr and/or Mg concentration in the samples.

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