Some features of thermo‐activated structural transformation of biogenic and synthetic Mg‐containing apatite with β‐tricalcium‐magnesium phosphate formation

Abstract

Temperature transformation of biogenic and synthetic Mg-containing apatite with β-tricalcium-magnesium phosphate (β-TCMP) formation was investigated by X-ray diffraction. Samples were annealed in air at the temperature range from 600 to 1200 °C at intervals 100 °C and cooled down to room temperature. The appearance of β-TCMP was ascertained in samples annealed at 800 °C. As revealed, the relative amount of β-TCMP increases and Mg concentration in this phase decreases as the annealing temperature is raised. While this, the replacement degree of Ca by Mg in the β-TCMP lattice is the annealing temperature function and does not depend either on sample origin (biogenic/synthetic) or on initial Mg concentration. The results of present work together with other investigation data testify to a high thermally activated mobility of Mg both in structure of Mg-containing apatites and in the structure of β-TCMP formed after thermal decomposition. Obtained data can be used for new biomaterials design with varied prolongation of Mg released into the living biological tissue.

Structural and crystal-chemical characteristics of the apatite deposits from human aortic walls

“…An important feature of bioapatites is their high-temperature phase decomposition with the formation of two-phase and sometimes three-phase systems [ 16 – 18 , 20 , 22 ]. The analysis of the products of bioapatite’s phase decomposition seems to be very informative in studying defects in the structure of natural samples, as confirmed by a number of relevant studies [ 19 , 21 , 23 ]. In fact, very small variations of the Ca/P ratio in the raw bioapatite lead to great changes in material composition and characteristics after thermal treatment.…”

“…The presence of Mg in the samples of synthetic and biogenic apatite leads during its thermal decomposition to the formation of the crystalline phase of β-tricalcium magnesium phosphate. Quantitative characteristics of this phase give information about the original content and localization of magnesium in biominerals [ 19 ].…”

Thermal transformations of the mineral component of composite biomaterials based on chitosan and apatite

“…The choice of temperatures at which the initial composite materials have been annealed was caused by the facts that in the biogenic and synthetic apatite after 700 °C the significant increase of crystallite size is observed [13]; after annealing at 900 and 1100 °C the emergence and development of other crystalline phases is possible, which is caused by structural and concentrational imperfections of initial apatite [8,17]. Therefore, comparing the phase composition and substructure characteristics in the temperature series of samples with different chitosan/apatite ratios it is possible to make certain conclusions about the formation of the initial nanocrystalline apatite in the presence of chitosan.…”

Preparation of Beta‐Tricalcium Phosphate Powder Substituted with Na/Mg Ions by Polymerized Complex Method

“…In this study, we synthesized b-TCP powder doped with/without metal ions by the polymerized complex method using only Ca(NO 3 ) 2 Á 4H 2 O, metal nitrate [NaNO 3 or Mg(NO 3 ) 2 Á 6H 2 O], and PBTA: we selected sodium (Na 1 ) ions and magnesium (Mg 21 ) ions because these ions are closely related to the biomineralization processes such as cell adhesion, apatite mineral nucleation, bone metabolism, and resorption. 55,56,[58][59][60][61][62][63][64][65] In addition, we investigated the formation mechanisms and thermal behaviors of the precursors and the composition and particle morphology of the powder after heating the precursors in order to discuss the effect of metal ions on these characteristics.…”