Synthesis and Characterization of Nano Hydroxyapatite from Waste Egg Shells for Orthopedic and Dental Applications

Abstract

Hydroxyapatite (HAp) is a type of material that is widely used in orthopedic and dentistry as a bio-coating of implants for improvement in its osteointegration with bone tissue. HAp was processed and synthesized by a precipitation technique by utilizing a biological means eggshell. The synthesis technique involved the calcination of eggshell powder to obtain calcium oxide and then its titration at a controlled flow rate with phosphoric acid. Fourier Transform Infrared Spectroscopy (FTIR) and X-Ray diffraction (XRD) investigations were carried out to confirm the formation of HAp. Whereas, the Scanning Electron Microscopy (SEM) demonstrated the shape and structure of the as-synthesized nanohydroxyapatite powder. The obtained results correlate with the literature. It was observed that the HAp formed was highly crystalline and all the peaks corresponded with HAp based on the standard XRD pattern of HAp (JCDPS card no. 09-432). It was clear from the small peaks that some Tri-Calcium Phosphate was also formed along with the hydroxyapatite. Very less crystallinity can be seen in the SEM micrograph of the eggshell. The nHAp formed was subjected to thermal treatment in a controlled environment. The thermal treatment resulted in improved crystallinity and refined grain size. It is noted that higher surface area biogenic HAp with highly interconnected nanoparticles will be useful in bone morphogenesis during bone surgery.