Synthesis and characterization of apatite silicated powders with wet precipitation method

The synthesis of apatite silicated Ca10(PO4)6-x(SiO4)x(OH)2-x (SiHA) with 0≤x≤2 was investigated using a wet precipitation method followed by heat treatment using calcium carbonate CaCO3 and phosphoric acid H3PO4 and silicon tetraacetate SiC8H20O4 (TEOS) in medium of water ethanol, with three different silicate concentrations. After drying, the samples are ground and then characterized by different analytical techniques like X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning electron Microscopy (SEM) and chemical analysis

Application of Statistical Experimental Design and Surface Plot Technique to Optimize Oxygenated Apatite Synthesis

This work deals with oxygenated apatite synthesis from calcium chloride and phosphoric acid using a wet precipitation method. An experimental design is applied to precise the influence of the synthesis parameters (pH of the reaction medium, atomic ratio Ca/P of the reagents, concentration of the calcium solution (Ca2+), temperature of the reaction medium (T), and duration of the reaction (D)) on the chemical composition (Ca/P molar ratio, % O2, and % O22−). An empirical model was developed and validated by applying the ANOVA analysis incorporating the interaction effects of all parameters and optimized using the response surface methodology. A reproducible synthesis of more oxygenated apatite with speed of dissolution adaptable to that of the osseous neoformation and allowing a progressive diffusion of oxygenated species (Ca/P = 1.575) is attained

Characterization of antiseptic apatite powders prepared at biomimetics temperature and pH

Antiseptic apatite-based calcium phosphates were prepared as the single-phase powders. Phosphocalcic oxygenated apatites were synthesized from calcium salts and orthophosphate dissolved in oxygenated water solution at 30%, under the biomimetic conditions of 37 °C and pH 7.4. The characterization and chemical analysis of the synthesized biomimetic apatite powders were performed by scanning electron microscopy (SEM), powder X ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FT-IR) and chemical analysis. The obtained materials are a calcium deficient apatites with different morphologies

Chitosan effects on glass matrices evaluated by biomaterial. MAS-NMR and biological investigations.

International audienceBioactive glass 46S6 and biodegradable therapeutic polymer (Chitosan: CH) have been elaborated to form 46S6-CH composite by freeze-drying process. The kinetics of chemical reactivity and bioactivity at the surface were investigated by using physicochemical techniques, particularly solid-state MAS-NMR. Immortalized cell line used to construct multicellular spheroids was employed as three-dimensional (3D) cell cultures for in vitro studies. Obtained results showed a novel structure of the composite; the chemical treatment (ultrasound, magnetic stirring, freeze drying process and lyophilization) led the bioactive glass particles to be loaded in the chitosan-based materials. 29Si and 31P MAS-NMR results showed the emergence of two new species, QSi 3(OH) and QSi 4, which are characteristic of the vitreous network dissolution in simulated body fluid (SBF). MAS-NMR also confirmed the formation of amorphous calcium phosphate (ACP) at the surface of the initial 46S6-CH. Three-dimensional (3D) cell cultures highlighted the effect of chitosan, where the cell viability reached up to 78% in 46S6-CH composite and up to 67% in 46S6. The association of (CH) and bioactive glass (BG) matrix promotes a highly significant bioactivity, demonstrating surface bone formation and satisfactory behavior in biological environment

Mix design optimization of metakaolin-slag-based geopolymer concrete synthesis using RSM

Geopolymers have attracted considerable attention recently due to their promising environmental and economic benefits. This study used alkali activation to create an environmentally friendly material with good workability and high mechanical qualities from metakaolin from Oulmès, Morocco, and SONASID-Jorf steel factory slag (BFS). The authors optimized geopolymer synthesis using mixture design and Response Surface Methodology. The results demonstrate the importance of components in ANOVA modelling. This is evidenced by the high experimental Fisher factor (FCv = 16.8916 and FSt = 20.5902), which exceeds the critical value of the Fisher factor (Fc = 15.52) according to the F-test. In addition, the high values of the coefficient of determination (R2) and the adjusted coefficient of determination (R2Adj) indicate strong correlations between the experimental and calculated values (R2Cs = 95.48 % and R2Adj-Cs = 89.83 %, and R2St = 96.26 % and R2Adj-St = 91.58 %). Furthermore, the response surface analysis in the range of variables suggests that metakolin, blast furnace slags, and alkaline activation solution are best for the synthesis of a 35.31 MPa geopolymer. Under ideal conditions, Fourier transform infrared spectroscopy (FTIR) revealed bands associated with the asymmetric strain modes Si–O–Si and Al–O–Si in the metakaolin-BFS-based geopolymer. Similarly, X-ray diffraction (XRD) analysis shows a remarkable peak between 15° and 40° in 2Ɵ, indicating a significant growth rate of the amorphous phase corresponding to geopolymer formation. This study shows that design of experiments and response surface methods can optimize geopolymer synthesis, producing a material with high mechanical characteristics and good workability