Effect of Sintering Conditions on the Structural and Morphological Characteristics of Hydroxyapatite Synthesized from Belida Fish (Chitala lopis) Bone

Abstract

Hydroxyapatite (HA) was synthesized from Chitala lopis (belida fish) bone waste as a sustainable and low-cost natural source, and the effects of sintering temperature and atmosphere on its properties were evaluated. Bone powder was sintered at 600–1000°C under open crucible (FBO) and closed crucible (FBC) conditions. X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) confirmed HA formation, with crystallinity and crystal size increasing at higher temperatures. Scanning electron microscopy (SEM) revealed morphological evolution from porous, irregular structures at lower temperatures to denser, more compact morphologies at higher temperatures. FBO conditions promoted larger crystallites and oriented growth, whereas FBC enhanced densification and reduced porosity. X-ray fluorescence (XRF) detected trace elements (Zn, Fe, Ti) potentially beneficial for bioactivity. Findings indicate that both sintering temperature and atmosphere significantly influence HA purity, crystallinity, and morphology, enabling property optimization for applications from porous adsorbents to dense bone implant materials.