title: The effect of processing parameters and solid concentration on the mechanical and microstructural properties of freeze-casted macroporous hydroxyapatite scaffolds.
abstract: The design and fabrication of macroporous hydroxyapatite scaffolds, which could overcome current bone tissue engineering limitations, have been considered in recent years. In the current study, controlled unidirectional freeze-casting at different cooling rates was investigated. In the first step, different slurries with initial hydroxyapatite concentrations of 7-37.5 vol.% were prepared. In the next step, different cooling rates from 2 to 14 °C/min were applied to synthesize the porous scaffold. Additionally, a sintering temperature of 1350 °C was chosen as an optimum temperature. Finally, the phase composition (by XRD), microstructure (by SEM), mechanical characteristics, and the porosity of sintered samples were assessed. The porosity of the sintered samples was in a range of 45-87% and the compressive strengths varied from 0.4 MPa to 60 MPa. The mechanical strength of the scaffolds increased as a function of initial concentration, cooling rate, and sintering temperature. With regards to mechanical strength and pore size, the samples with the initial concentration and the cooling rate of 15 vol.% and 5 °C/min, respectively, showed better results.
authors.affiliation: Nanotechnology and Advance Materials Department, Materials and Energy Research Center, Karaj, Alborz, Iran. s.farhangdoust@merc.ac.ir
authors.forename: S
authors.initials: S
authors.lastname: Farhangdoust
authors.affiliation: Nanotechnology and Advance Materials Department, Materials and Energy Research Center, Karaj, Alborz, Iran.
authors.forename: A
authors.initials: A
authors.lastname: Zamanian
authors.affiliation: Nanotechnology and Advance Materials Department, Materials and Energy Research Center, Karaj, Alborz, Iran.
authors.forename: M
authors.initials: M
authors.lastname: Yasaei
authors.affiliation: Nanotechnology and Advance Materials Department, Materials and Energy Research Center, Karaj, Alborz, Iran.
authors.forename: M
authors.initials: M
authors.lastname: Khorami
mesh_terms: D018786:Bone Substitutes / Q000737:chemistry; D019245:Compressive Strength; D017886:Durapatite / Q000737:chemistry*; D005615:Freezing; D055595:Mechanical Phenomena; D016062:Porosity; D013696:Temperature; D054457:Tissue Scaffolds / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D018786:Bone Substitutes; D017886:Durapatite