In this study, the effects and interactions of reaction time and capping agent assistance during sol-gel synthesis of magnesium substituted hydroxyapatite nanopowder (MgHA) on hydroxyapatite (HA) to β-tricalcium phosphate (β-TCP) ratio, Ca/P ratio and mean crystallite size was examined experimentally as well as through statistical analysis. MgHA nanopowders were synthesized by sol-gel technique...

The substitution of selenium oxyanions in the hydroxyapatite structure was examined using multinuclear solid-state resonance spectroscopy (ssNMR). The study was supported by powder X-ray diffractometry (PXRD) and wavelength dispersion X-ray fluorescence (WD-XRF). Samples of pure hydroxyapatite (HA300) and selenate (HA300-1.2SeO4) or selenite (HA300-1.2SeO3) substituted hydroxyapatites were synt...

Hydroxyapatite (HA) is a calcium phosphate bioceramic widely used for bone grafting and augmentation purposes. The biological response of HA can be improved through chemical and microstructural modifications, as well as by manufacturing it as macroporous implants. In the present study, calcium deficient hydroxyapatite (CDHA) and Si substituted hydroxyapatite (SiHA) macroporous scaffolds have be...

With its good properties of biocompatibility and bioactivity hydroxyapatite (HA) is highly used as bone substitutes and as coatings on metallic prostheses. In order to improve the bioactive properties of HA, we have elaborated Zn2+ doped hydroxyapatite. Zn2+ ions substitute for Ca2+ cations in the HA structure and four Zn concentrations (Zn/Zn+Ca) were prepared at 0.5, 1, 2 and 5 at.%. To study...

Aim. To synthesize cyclobutane-derived amines and carboxylic acids bearing CH2F or CHF2 groups in the α position; to determine regularities of effect fluoroalkyl substituents on acid-base properties title compounds.Results discussion. Synthetic approaches 1-(fluoromethyl)- 1-(difluoromethyl)cyclobutanamines, 1-(difluoromethyl)cyclobutanecarboxylic have been developed. It has found that pKa (pKa...

The viscosities of fluorineand water-bearing melts based on albite composition have been determined at 7.5, 15 and 22.5 kbar by the falling-sphere method. All melt viscosities decrease isothermally with increasing pressure. At 12000( ` the vi~osity of the fluorine-bearing melt (albite + 5.8 wt.C~ fluorine substituted for oxygen, denoted AbF, O n) decreases from 5000 + 750 P at 7.5 kbar to 1600 ...

The synthesis of 4-(substituted benzylidene)-2-(pyrazin-2-yl) oxazol-5(4H)-one was achieved in two steps, In first step, pyrazine-2-carboxamide  dissolved in EtOH, 10% KOH solution with ClCH2COOH produced compound 2-(pyrazine-2-carboxamido) acetic acid (II) and in second step, compound (II) in (CH3CO)2O with aromatic aldehyde, and catalyst potassium ace...

Experimental chemistry and atomic modelling studies were performed here to investigate a novel ionic co-substitution in hydroxyapatite (HA). Zinc, silicate co-substituted HA (ZnSiHA) remained phase pure after heating to 1100 °C with Zn and Si amounts of 0.6 wt% and 1.2 wt%, respectively. Unique lattice expansions in ZnSiHA, silicate Fourier transform infrared peaks and changes to the hydroxyl I...

INTRODUCTION: Strontium plays important role in stimulating the growth of osteoblasts and enhancing the formation of new bone. Therefore, a strontium related compound strontium ranelate (SR) has recently been suggested for use as a daily supplement to treat osteoporosis. However, the true effect of strontium to the stability of hydroxyapatite (HAp) has not been well understood yet, such as why ...

The feasibility of soft mechanochemical synthesis was studied here for hydroxyapatite with various types substitution. It shown that this method allows obtaining hydroxyapatites substituted copper or iron cations and cosubstituted zinc silicate groups. Thermal stability the synthesized samples evaluated. found to preserve phase homogeneity material, temperature during preparation ceramic produc...