synthesis of hydroxyapatite nanoparticles trough polyelectrolyte-modified microemulsions

the paper is focused on the formation of hydroxyapatite nanoparticles (hap) in polyelectrolyte-modified microemulsions, in a microemulsion template phase consisting of cyclohexane, water, cationic surfactant and cosurfactant, in the presence of na-polyacrylate (paa) as an anionic polyelectrolyte. it is shown that paa, can be incorporated into the individual inverse microemulsion droplets. the microemulsion droplets and paa-filled microemulsion droplets can be successfully used as a template phase for the nanoparticles formation. prepared hap in presence of polyelectrolyte has a different morphology from samples which are synthesized in absence of polyelectrolyte. paa leads to formation of needle-like hap (20-30nm in diameter and 100-200nm in length). formation of hap at room temperature was confirmed by x-ray diffraction (xrd) and fourier transform infrared spectroscopy (ft-ir). size and morphology of the hap samples were characterized using transmission electron microscopy (tem).