Effect of Citrate on Morphological and Structural Properties of Hydroxyapatite Nanoparticles Synthesized by Wet Chemical Precipitation Method

Hydroxyapatite (HAp) nanoparticles organically modified with citrate group are fabricated via a simple wet chemical precipitation method. The as-synthesized nanoparticles are structurally characterized by TEM, XRD, FT-IR, EDAX and dynamic light scattering (DLS) to investigate in detail the influence of surface coating ligand i.e. citrate on HAp morphology, crystal structure, phase and colloidal stability of the particles. Production of single phase with hexagonal crystal structure is evident by XRD analysis. The work shows mesoporous structure could be synthesized under the influence of citrate as confirmed by TEM image and N 2 adsorption−desorption isotherm. The experimental results indicate that citrate strongly influences HAp crystallization giving reduced particle size and uniform distribution. BET and BJH analysis indicate large surface area 135.74 m 2 /g and pore diameter of 9.86 nm with a total pore volume of 0.41 cm 3 /g respectively for 1 : 1 citrate to calcium ion molar ratio. The appropriate surface area and pore entrance significantly indicate potentiality to apply into biomedical fields as drug loading/delivery application.