Calcium Phosphate Materials Prepared from Precipitates with Various Calcium:Phosphorus Molar Ratios

Abstract

Depending on the calcium:phosphorus molar ratio of the initial precipitates determined by precipitation conditions (calcium:phosphorus molar ratio of reactants and pH of reaction environment), after sintering at 1250°C, monophase, biphase, or triphase ceramics consisting of hydroxyapatite, β‐tricalcium phosphate, α‐tricalcium phosphate, and calcium oxide were obtained. The phase composition and properties—i.e., density, shrinkage, hardness, bending strength, and roughness—of the fractured surfaces of the isostatically re‐pressed sinters were determined.

Kinetics of 1H → 31P NMR cross‐polarization in bone apatite and its mineral standards

“…[24,34,35,48] Stoichiometric HA was synthesized by the wet chemical method with the Ca/P ratio of 1.67. [49] It was predried in air to give as-synthesized sample HAh. HAh was then calcined at 1073 K to give HAc.…”

Mechanical properties of HAp–ZrO2 composites

“…ZrO 2 powder was added to the appropriate amount of an intensively stirred aqueous suspension of Ca(OH) 2 resulting from the reaction of CaO with H 2 O. HAp was precipitated in the presence of ZrO 2 particles by addition of H 3 PO 4 solution. 9,10 The precipitates thus obtained were several times rinsed with distilled water, dried at temperature 90 • C during 48 h, heat treated at a temperature of 800 • C with 3 h soaking time in air atmosphere and ground. Powders were milled in a "attritor"-type mill in ethyl alcohol, using grinding balls made of ZrO 2 .…”

Hydroxyapatite nanorods/poly(vinyl pyrolidone) composite nanofibers, arrays and three-dimensional fabrics: Electrospun preparation and transformation to hydroxyapatite nanostructures

“…Synthetic HAp particles, films, coatings and porous skeletons with high biocompatibility are widely used in various biomedical applications [2]. Numbers of methods have been used for the synthesis of HAp, such as the wet chemical, mechano-chemical [3,4] and sol-gel methods [5,6]. HAp materials with different morphologies, including nanorods [7], plate-like nanocrystals [8], nanoparticles [9] and three-dimensional (3-D) structures [10][11][12][13] have been synthesized.…”