Effect of Zinc and Strontium Doping on The Density and Hardness of Nanohydroxyapatite

Abstract

Hydroxyapatite is a biocompatible, bioactive, and non-toxic bioceramic that constitutes the primary inorganic material in human bone. Synthetic hydroxyapatite is not suitable for load-bearing uses due to its insufficient mechanical strength. The mechanical properties of nano-hydroxyapatite can be improved by incorporating small amounts of trace elements that are present in bone. Zinc is found in bone at around 0.01 - 0.05 %, and strontium around  0.01 - 0.1 %.  The introduction of zinc and strontium improves the properties of nanohydroxyapatite. In this study, nanohydroxyapatite and its doped samples are synthesized using a simple chemical precipitation method. The structural analysis has been done using Fourier Transform Infrared (FTIR) and X-ray diffraction (XRD) Spectroscopic techniques.  The thermal properties of the synthesized sample were studied using TGA. The elemental analysis was done using EDX analysis, and the morphological analysis was done by HRTEM. The density of the sintered sample was measured using Archimedes' principle, and its Vickers hardness was also evaluated. Findings reveal that the incorporation of zinc and strontium improves the density and hardness of nanohydroxyapatite.