Synthesis and characterization of chlorinated hydroxyapatite as novel synthetic bone substitute with negative zeta potential

In the present work, chlorine doped hydroxyapatite (ClHA), with varying degrees of ion replacement was successfully synthesized by a simple ball milling technique. The resulting powders were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, Field emission scanning electron microscopy and particle size analyzer. The zeta potential of the powders was performed in physiological saline (0.154 M). The results confirmed the formation of apatite as the main phase in all chlorine substituted powders except for some incremental changes in the lattice parameter ‘a’ and unit cell volumes of the resultant powders. However, the crystallinity of the powders declined from 96% to 83%. Fourier transform infrared spectroscopy results confirmed the incorporation of Cl ions in the apatite lattice by the appearance of new bands at 677 cm^-1. FESEM results revealed that the crystallites have grown into grains with no major agglomeration. Vicker hardness test results revealed a hardness value of 2.65 ± 0.258 GPa for ClHA4 dense bodies at a load of 200g. Zeta potential analysis of the powders suggested that ClHA nanopowders can prove to be a potential bone implant material.