Syntheses of hydroxyapatite from natural sources.

We report on a comparison of methods based on XRD patterns for calculating crystal size In this case, XRD peaks were extracted from hydroxyapatite obtained from cow, pig, and chicken bones Hydroxyapatite was synthesized through the thermal treatment of natural bones at 950 °C XRD patterns were selected by adjustment of X-Pert software for each method and for calculating the size of the crystals Methods consisted of Scherrer (three models), Monshi-Scherrer, three models of Williamson-Hall (namely the Uniform Deformation Model (UDM), the Uniform Stress Deformation Model (USDM), and the Uniform Deformation Energy Density Model (UDEDM)), Halder-Wanger (H-W), and the Size Strain Plot Method (SSP) These methods have been used and compared together The sizes of crystallites obtained by the XRD patterns in each method for hydroxyapatite from cow, pig, and chicken were 1371, 457, and 196 nm in the Scherrer method when considering all of the available peaks together (straight line model) A new model (straight line passing the origin) gave 60, 60, and 53 nm, which shows much improvement The average model gave 56, 58, and 52 nm, for each of the three approaches, respectively, for cow, pig, and chicken The Monshi-Scherrer method gave 60, 60, and 57 nm Values of 56, 62, and 65 nm were given by the UDM method The values calculated by the USDM method were 60, 62, and 62 nm The values of 62, 62, and 65 nm were given by the UDEDM method for cow, pig, and chicken, respectively Furthermore, the crystal size value was 4 nm for all samples in the H-W method Values were also calculated as 43, 62, and 57 nm in the SSP method for cow, pig, and chicken tandemly According to the comparison of values in each method, the Scherrer method (straight line model) for considering all peaks led to unreasonable values Nevertheless, other values were in the acceptable range, similar to the reported values in the literature Experimental analyses, such as specific surface area by gas adsorption (Brunauer-Emmett-Teller (BET)) and Transmission Electron Microscopy (TEM), were utilized In the final comparison, parameters of accuracy, ease of calculations, having a check point for the researcher, and difference between the obtained values and experimental analysis by BET and TEM were considered The Monshi-Scherrer method provided ease of calculation and a decrease in errors by applying least squares to the linear plot There is a check point for this line that the slope must not be far from one Then, the intercept gives the most accurate crystal size In this study, the setup of values for BET (56, 52, and 49 nm) was also similar to the Monshi-Scherrer method and the use of it in research studies of nanotechnology is advised

https://www.mdpi.com/2079-4991/10/9/1627/pdf

Comparing Methods for Calculating Nano Crystal Size of Natural Hydroxyapatite Using X-Ray Diffraction.

The influence of sintering temperature on the properties of compacted bovine hydroxyapatite

Utilization of biowaste eggshells to synthesize nanocrystalline hydroxyapatite powders

Hydroxyapatite (HAp) is a bioactive and vital material which has found many applications in the biomedical and clinical fields. This bio-ceramic powder can be synthesized via different bio-waste materials. In this study, the production of natural nanohydroxyapatite was produced through calcination of untreated turkey femur-bone waste powder at 850 °C followed by ball milling the powder. The obtained powder was characterized using X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analysis. The morphology, size, and elemental composition of obtained turkey hydroxyapatite (THA) particles were investigated by scanning electron microcopy (SEM), transmission electron microcopy (TEM), and energy dispersive spectroscopy (EDS) analysis, in which the average particle size of ball milled THA was found to be about 85 nm with a Ca/P ratio of 1.63. The powder was then cold pressed and later sintered at 850, 950, 1050, and 1150 °C to evaluate its mechanical properties in terms of compressive strength and hardness. The results revealed that the strength and hardness of the samples increased by increasing the sintering temperature up to 1150 °C. Finally, the maximum values of hardness and compressive strength of the sintered THA were obtained at 1150 °C (37.44 MPa and 3.2 GPa, respectively).

Synthesis and Characterization of Natural Nano-hydroxyapatite Derived from Turkey Femur-Bone Waste.

The production of natural hydroxyapatite (HAp) specifically from cortical bovine bones and natural calcite was studied in this paper. Bovine hydroxyapatite (BHA) was produced from bovine bone in bulk form by de-fatting continued with calcination at 900°C. Natural calcite hydroxyapatite (CHA) was produced by hydrothermal method. It was confirmed from XRD, FTIR, and SEM results that HA have been successfully produced from natural sources like bulk bovine bone and natural calcite. The results also show that the crystallinity of BHA is higher than CHA, matching with the hardness test results of sintered BHA and CHA.

D.A. Nasution

Papers

Preparation and Characterization of Natural Hydroxyapatite: A Comparative Study of Bovine Bone Hydroxyapatite and Hydroxyapatite from Calcite