Properties of hydroxyapatite produced by annealing of bovine bone

_________________________________________________________________________________ ABSTRACT—In the present study, hydroxyapatite (HAp) was synthesized from biosources bovine bone in a cost effective and ecofriendly way. Bovine bone were converted to hydroxyapatite (HAP) by a heat treatment method at different temperatures. The final product were characterized by X-ray diffraction, Scanning Electron Microscopy, Energy Dispersive X-ray spectroscopy (EDX) and FT-IR. The phase, purity and crystallinity of different calcined HAp powder were analysed. It confirms that material prepare from biosources cow bone is hydroxyapatite indeed. The natural HAp obtained by calcining at 850 °C shows the desired quality. In addition, SEM results revealed the formation of microstructured HAp 0.4 m at 700 °C and crystal agglomeration was observed with an increase in calcination temperature. Calcium and Phosphorus contents were 20 % and 11.4%, respectively, which correspond to the Ca/P molar ratio of non...

This article focuses on the study of the thermal, vibrational, structural, and morphological changes of hydroxyapatite from bovine bone obtained by a three-step process: calcination at two different low heating rates (2.5 and 5 C/min), at different temperatures ranging from 600 to 1100 C, and cooled in the air furnace. Differential scanning calorimetric and thermogravimetry showed that for T[700 C, no organic compounds were present in the bone matrix. Scanning electron microscopy images showed that the heating rates affect the morphology of the samples. The primary porosity originated by the presence of fat and protein disappears after the coalescence of the poly-hydroxyapatite crystals, and for T[800 C, a disorder–order transition (poly-crystal–single crystal) occurs. Full-width at the half-maximum of X-ray diffraction patterns indicated that the heating rate affects the structure of the BIO-Hap. Diffraction peak corresponding to calcium carbonate disappears from X-ray patterns of the samples calcined above 700 C. The disorder–order (poly-crystal–single crystals) transition occurs for T>900 °C. Raman experiments showed that for T>700 °C, no organic phases are present in the samples. Dihydroxylation of hydroxyapatite is present for temperatures up to 800 °C originated Whitlockite. The same thermal conditions during sample calcination process were assured by using a controlled computer system.

This article is focused on the study of cooling rate effects on the thermal, structural, and microstructural properties of hydroxyapatite (HAp) obtained from bovine bone. A three-step process was used to obtain BIO-HAp: hydrothermal, calcinations, and cooling. Calcined samples in a furnace and cooling in air (HAp-CAir), water (HAp-CW), and liquid nitrogen (HAp-CN2), as well as an air cooled sample inside the furnace (HAp-CFAir), were studied. According to this study, the low cooling rate that was achieved for air cooled samples inside the furnace produce single crystal BIO-HAp with better crystalline quality; other samples exhibited polycrystalline structures forming micron and submicron grains. V C 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 339–344, 2016.

Materials Today: Proceedings, 2019

This study reports the feasibility of isolation of hydroxyapatite (HA) from chicken bone bio-waste and the effect of pre-treatment and calcination process of bones on micro-structural and physico-chemical properties of HA. Chicken bones are treated with acid, alkali and acid-alkali solution followed by calcination at 700, 800 and 900°C respectively. The calcined bones are characterized and compared. It is found that acid treated bones calcined at 900°C yields pure phase of crystalline HA particles of size 600 nm with good pore morphology having pore diameter 208 nm, Ca/P atomic ratio of 1.653 and high thermal stability, ideal for biomedical applications.

Ceramics International, 2010

The present work focus the study of cortical bone samples of different origins (human and animal) subjected to different calcination temperatures (600, 900 and 1200 8C) with regard to their chemical and structural properties. For that, not only standard techniques such as thermogravimetric analysis, Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy were used but also mercury intrusion porosimetry. The latter technique was applied to evaluate the effects of the temperature on the microstructure of the calcined samples regarding porosity and pore size distribution. Although marked alterations in structure and mineralogy of the bone samples on heating were detected, these alterations were similar for each specimen. At 600 8C the organic component was removed and a carbonate apatite was obtained. At 900 8C, carbonate was no longer detected and traces of CaO were found at 1200 8C. Crystallinity degree and crystallite size progressively increased with the calcination temperature, contrary to porosity that strongly decreased at elevated temperatures. In fact, relatively to the control samples, a significant increase in porosity was found in samples calcined at 600 8C (reaching values around 50%). At higher temperatures, a dramatic decrease was observed, reaching, at 1200 8C, values comparable to those of the non-calcined bone.

Epitoanyag - Journal of Silicate Based and Composite Materials, 2019

Calcium phosphate, particularly hydroxyapatite (HAp) is an important material in biomedical engineering applications. The development of HAp is continued rising due to the similarity and biomimetic requirements to the hard tissue of human body such as bone and dental. The purpose of our work was to produce and describe HAp bioceramic powder from environmental and cheap source (Bovine bone) by thermal process at various calcination temperatures. The analysis of Fourier transform infrared spectroscopy (FTIR) verified the formation of HAp because of the existence peaks related to phosphate and hydroxyl groups. The analysis of Raman confirmed findings of the FTIR the formation of HAp due to the appearance of peaks at 960 and 920 cm −1 related to a phosphate group. A result of Energy-dispersive X-ray spectrometry (EDS) also referred to Ca/P atomic ratio at 1000 °C was 1.6 that has been near stoichiometric hydroxyapatite (1.67) in human body.

Journal of Casting & Materials Engineering

Several biomedical materials have been employed as drug delivery systems, but natural Hydroxyapatite (HAP) has been proven to be exceptionally better than other materials owing to its excellent bioactivity and biocompatibility properties. In this study, nat­ural HAP was obtained from bovine and caprine bones and comparatively analysed for biomedical applications. The bones were hydrothermally treated, calcined in the temperature range of 700–1100°C, held for 2 hours in an electric furnace to remove the organic contents; milled, sifted with 150 μm mesh sieve and then characterized. It was revealed by Energy Dispersive X-Ray Spectroscopy (EDS) that the bovine and caprine bone samples calcined at 1000°C had calcium/phosphorus ratio (Ca/P) of 1.66 closest to the standard of 1.67. The bovine HAP showed the best crystallinity (86.23%) at 1000°C while caprine HAP had its highest (87.25%) at 1100°C. Fourier Transform Infrared Spectroscopy (FTIR) results revealed that the calcination tempera...

IFMBE Proceedings, 2007

The production of hydroxyapatite (HA) from bovine bones was studied in this paper. Bovine hydroxyapatite (BHA) was produced from bovine bone powders by calcination without compaction. The powders were calcined at temperatures ranging from 700-1100ºC. It was discovered that sample preparation has some influence on the calcination behavior of the bovine bone powders. XRD results confirmed that HA has been successfully produced but traces of α-TCP and β-TCP were also found. The Ca/P ratios of the BHA powders produced from the process have values greater than 2.0.

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