title: Synthesis and characterization of hydroxyapatite by microwave heating using CaSO4.2H2O and Ca(OH)2 as calcium source.
abstract: In this paper, synthesis of hydroxyapatite (HAp) in the absence or presence of 1.05 wt% magnesium oxide, as sintering additive, by heating in a microwave oven was studied. For this purpose, CaSO(4).2H(2)O, Ca(OH)(2), Mg(OH)(2) and (NH(4))(2)HPO(4) were used as raw materials. The total chemical reactions for all the studied compositions were observed after a 3 h microwave treatment. In case of pure hydroxyapatite, a powder with needle-like grains results. In the presence of Mg(OH)(2), the (Mg, Ca(2)).O.(HPO(4))(2).H(2)O hydrated phosphate is formed besides hydroxyapatite. Pure hydroxyapatite, thermally treated at 1,200 degrees C, mostly transforms in beta-Ca(3)P(2)O(8). By adding MgO into the precursor mixture, hydroxyapatite was stabilised, and found in a much greater proportion at 1,200 degrees C. After the thermal treatment, the hydroxyapatite, analysed by electronic microscopy, shows a prismatic morphology originating in its initial state.
authors.affiliation: Science and Engineering of Oxide Materials and Nanomaterials, Politehnica University of Bucharest, 1-7 Gheorghe Polizu Str., Bucharest, Romania.
authors.forename: Ion
authors.initials: I
authors.lastname: Teoreanu
authors.forename: Maria
authors.initials: M
authors.lastname: Preda
authors.forename: Alina
authors.initials: A
authors.lastname: Melinescu
mesh_terms: D001672:Biocompatible Materials; D002118:Calcium / Q000737:chemistry*; D002126:Calcium Hydroxide / Q000737:chemistry*; D002133:Calcium Sulfate / Q000737:chemistry*; D017886:Durapatite / Q000138:chemical synthesis*; D006358:Hot Temperature; D008277:Magnesium Oxide / Q000737:chemistry; D008872:Microwaves; D011208:Powders / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D001672:Biocompatible Materials; D011208:Powders; D008277:Magnesium Oxide; D017886:Durapatite; D002126:Calcium Hydroxide; D002118:Calcium; D002133:Calcium Sulfate