Morphological Diversity in Nanohydroxyapatite Synthesized from Waste Egg Shell : Verification and Optimization of Various Synthesis Parameters

Abstract

Biomimetic rod shaped hydroxyapatite (HA) was prepared from calcined eggshell waste with a particle width of 16 nm. The method adopted mainly aimed at preparing nanosized  deagglomerated  biocompatible HA by eco-friendly synthesis route. The method of preparation used sucrose as a dispersing medium to enable size reduction, morphology control and ready removal of dispersing agent at a temperature around 550 ^oC. Reported methods in existing literature mainly used organic templates as morphology regulators, the traces of which if left unremoved upon calcination can pose toxicological issues as far as their application in bio- realms are concerned. Spherical shaped HA of 19 nm particle diameter resulted when the calcium precursor used was uncalcined egg shell. The role of sucrose was confirmed by carrying out a control sample preparation in water, the powders obtained showed presence of agglomeration with an increased particle size. X-ray diffraction analysis (XRD) and Fourier transform infrared spectroscopy (FTIR) studies confirmed the formation of  pure HA . Scanning Electron Microscope (SEM) photographs gave the morphological diversities of different HA samples. Transmission Electron Microscopy (TEM) images substantiated the formation of uniform rod shaped HA. Elemental composition was confirmed by inductively coupled plasma– atomic emission spectroscopy (ICP-AES) and energy dispersive X-ray spectroscopy (EDXS)