Nanostructured Calcium Phosphates for Biomedical Applications

2014 ◽  
Vol 604 ◽  
pp. 212-215 ◽  
Author(s):  
Linda Vecbiskena ◽  
Luigi de Nardo ◽  
Roberto Chiesa

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.

2014 ◽  
Vol 604 ◽  
pp. 216-219 ◽  
Author(s):  
Marina Sokolova ◽  
Andris Putnins ◽  
Imants Kreicbergs ◽  
Janis Locs

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.


2012 ◽  
Vol 531-532 ◽  
pp. 250-253 ◽  
Author(s):  
Hong Quan Zhang ◽  
Ming Zhang ◽  
Lu Wei Fu ◽  
Yu Ning Cheng

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.


2014 ◽  
Vol 1015 ◽  
pp. 350-354
Author(s):  
Li Na Chen ◽  
Wan Yi Liu ◽  
Qi Lin Hu

Contraposing the waste anolyte of industry, the paper proposed a new chemical precipitation method to recover Mn (II) ions and Mg (II) ions from the waste solution using ammonium hydrogen carbonate and ammonium dihydrogen phosphate as precipitants, respectively. The technological conditions of dealing procedure such as the molar ratio of reactants, pH value, reaction temperature and time, aging time were investigated. The results shown that the removal rate of Mn (II) ions and Mg (II) ions reached to 96 % and 98 %, and the yields of MnCO3 and NH4MgPO4·6H2O reached to 91 % and 94 %, respectively. The residual solution was recycled to realize the treatment greenly, which could meet the needs of production and increase environmental benefits.


RSC Advances ◽  
2014 ◽  
Vol 4 (40) ◽  
pp. 20902-20908 ◽  
Author(s):  
Reza Zamiri ◽  
Avito Rebelo ◽  
Golriz Zamiri ◽  
Atena Adnani ◽  
Ajay Kuashal ◽  
...  

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


2014 ◽  
Vol 631 ◽  
pp. 61-66 ◽  
Author(s):  
Liga Stipniece ◽  
Kristine Salma-Ancane ◽  
Andris Putnins ◽  
Liga Berzina-Cimdina

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.


2021 ◽  
pp. 132142
Author(s):  
Mashrafi Bin Mobarak ◽  
Md. Sahadat Hossain ◽  
Zenefar Yeasmin ◽  
Monika Mahmud ◽  
Md. Maksudur Rahmana Sazia Sultana ◽  
...  

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