keywords: Comparative, hydroxyapatite, nanocrystals, physiological, precipitation hydrothermal
Nano crystalline hydroxyapatite was prepared at physiological conditions of pH (7.4) and temperature (37oC) by precipitation and hydrothermal methods using Ca(NO3).4H2O and NH4H2PO4 as precursors. The prepared samples were characterized via Particle size Analyser (PSA), Fourier transform infrared spectroscope (FT-IR), energy dispersive X-ray fluorescence (XRF/EDX), X-ray diffraction (XRD), Brunauer–EmmettTeller (BET), Scanning electron microscopy(SEM), Transmission electron microscopy (TEM) and Thermogravimetric/Differential thermal analyser (TG/DTA).The wet precipitated and hydrothermally synthesized crystals revealed Ca/P of 1.65 and 1.66, average particle size distribution of 26 and 29 nm specific surface area/ pore size/pore volume before and after calcination of (106 and 96 m2g-1/18 and 21.35 nm/0.65 and 0.48 ccg-1) and (102 and 95 m2g-1/19.40 and 22.6 nm/0.62 and 0.43 ccg-1), crystalline size (D)/ degree of crystallinity (Xc) of (5.03 nm/0.53) and (5.08 nm/1.82) a highly agglomerated uneven rod-like structures, respectively. The crystallinity/size and morphology as revealed by XRD and SEM were confirmed from the TEM images having sizes less than 100 nm and the crystalline nature of both powders. TG/DTA revealed the thermal stabilities of both powders beyond 800oC.