Isothermal phase transformations of bovine-derived hydroxyapatite/bioactive glass: a study by design of experiments
Publication date: Available online 13 November 2018
Source: Journal of the European Ceramic Society
Author(s): July Andrea Rincón-López, Jennifer Andrea Hermann-Muñoz, David Andrés Fernández-Benavides, Astrid Lorena Giraldo-Betancur, Juan Manuel Alvarado-Orozco, Juan Muñoz-Saldaña
In this work, a systematic methodology to obtain third-generation bioceramics within the Ca2SiO4-Ca3(PO4)-NaCaPO4ternary system is proposed. The synthesis of Silicocarnotite (Ca5-x(PO4)2+x(SiO4)1-x; x ≤ 0.3) (SC) and Nagelschmidtite (Ca7-xNax(PO4)2+x(SiO4)2-x; x ≤ 2) (Nagel) single phases, from mixtures of bovine-derived HAp (BHAp) and 45S5-bioactive glass (BG) as precursors was developed using design of experiments (DoE). A combination of milling and sintering processing parameters was established by statistical analysis to optimize the microstructural and mechanical properties of BHAp/BG ceramics. The optimized sintering temperature obtained with simultaneous responses was 1220 °C. Variations in BHAp/BG ratios lead to isothermal phase transformation to single crystalline phases, where 85/15 and 70/30 vol:vol ratios transformed to SC and Nagel, respectively. Finally, the proposed methodology allows a feasible composition control depending only of BHAp/BG ratio to obtain non-stoichiometric SC and Nagel phases with potential applications in bone repair.