Template-directed hydrothermal synthesis of dandelion-like hydroxyapatite in the presence of cetyltrimethylammonium bromide and polyethylene glycol

A template-directed synthetic method, using surfactant cetyltrimethylammonium bromide (CTAB) as a template and co-surfactant polyethylene glycol (PEG600) as a co-template under hydrothermal conditions, has been applied to obtain dandelion-like HAp. The morphology, size, crystalline phase, chemical composition, physical characteristics, and thermal behavior of the product were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), Fourier ransform infrared spectroscopy (FTIR), induced coupled plasma spectroscopy (ICP), BET (Brunauer, Emmett, and Teller) method, and simultaneous thermal analysis (STA). SEM and TEM observations showed in the presence of CTAB and a certain concentration of PEG600 (30%) HAp crystals have a uniform dandelion-like morphology with a diameter of about 80-150 nm and aspect ratio of about 20 for each tooth. Dandelion-like HAp crystals have a high surface area of 88 m2 g−1 showing potential applications. The template action of CTAB and co-template action of PEG600 are also discussed.