title: Microwave accelerated synthesis of nanosized calcium deficient hydroxyapatite.
abstract: Rapid synthesis of calcium deficient hydroxyapatite (CDHA, Ca(10-x)(HPO4)x(PO4)(6-x)(OH)(2-x)) with Ca/P ratio 1.5 was done by precipitation using calcium nitrate tetra-hydrate and phosphoric acid and subsequently subjecting to microwave irradiation in a domestic microwave oven for 15 min. Transmission electron microscopy analysis shows needle like morphology of CDHA having length 16-39 nm and width 7-16 nm. The synthesized CDHA has the characteristic HPO4(2-) vibration band at 875 cm(-1) in Fourier transform infrared (FT-IR) spectra. The X-ray powder diffraction (XRD) analysis shows a pattern corresponding to stoichiometric hydroxyapatite (HA) with broad peaks suggesting that CDHA particles were nanosized. Fourier transform Raman spectroscopy (FT-Raman) do not indicate any fluorescence band that is characteristic of non-stoichiometric HA. The thermal decomposition of CDHA to beta tricalcium phosphate (beta-TCP) was also studied for the additional confirmation. The nanosized CDHA was found to be stable up to 600 degrees C.
authors.affiliation: Department of Metallurgical and Materials Engineering, Indian Institute Technology Madras, Chennai, 600036, India.
authors.forename: A
authors.initials: A
authors.lastname: Siddharthan
authors.forename: S K
authors.initials: SK
authors.lastname: Seshadri
authors.forename: T S
authors.initials: TS
authors.lastname: Sampath Kumar
mesh_terms: D002118:Calcium / Q000737:chemistry*; D017886:Durapatite / Q000138:chemical synthesis*; D046529:Microscopy, Electron, Transmission; D008872:Microwaves; D036103:Nanotechnology; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
chemical_list: D017886:Durapatite; D002118:Calcium