XRD and FTIR study of A&B type carbonated hydroxyapatite extracted from bovine bone

Abstract

Bone is chiefly composed of 20-30 wt% organic phase, 60-70 wt% inorganic phase and about 5 wt% of water. The organic phase is comprised mostly of collagen, but lipids and non-collagenous proteins are other compounds in small concentration. Elasticity, flexibility, and resistance to the bone are provided by organic phase while the main component of the inorganic phase is hydroxyapatite (HAP).The present work focuses on the X-ray diffraction (XRD) and Fourier transforms infrared (FTIR) study of A&B type carbonated HAP extracted from bovine bone at different calcination temperatures (600, 800, and 1000 °C) without the use of chemicals/solvents. Therefore, it is a green technology. The hydrothermal method followed by heat treatment at different calcination temperatures was used to extract the A&B type carbonated HAP in this research. The characterizations of raw and calcined HAP powder were done by using XRD and FTIR techniques. XRD data showed that the extracted HAP is highly crystalline. It has a hexagonal crystal structure and crystallite size is in the range of range of 3.95 nm to 83.12 nm (Raw-HAP to HAP-1000). Crystallite size and crystallinity degree gradually increased with the intensification of calcination temperature from 600-1000 °C. The FTIR results confirmed the presence of phosphate (PO4−3), hydroxyl (OH−1) and carbonate (CO3−2) groups in the HAP powder. It is also confirmed that the extracted HAP is A&B type carbonated HAP as indicated by the position of the peaks at 1456 cm−1 and 1541 cm−1.