Preparation and characterization of porous hydroxyapatite reinforced with hydroxyapatite whiskers

Abstract

In this study, porous hydroxyapatite scaffolds reinforced with whiskers were fabricated. HAp whiskers were produced by the molten salt synthesis method using 5 different salt-HAp mixtures. The mixtures placed in alumina crucibles were heated to 900 oC with a heating rate of 5 oC/min in a muffle furnace and kept at this temperature for 2 hours and then cooled in the furnace. To clean the HAP crystals formed in the alumina crucibles from the reaction residues, they were washed many times with distilled water heated to 100 oC and filtered. HAp whiskers were mixed with HAp powder in certain proportions, and porous HAp reinforced with HAp whiskers were fabricated by using the sponge replica method. The synthesized whiskers and the scaffold structures were characterized by Scanning Electron Microscopy-Energy Dispersive X-Ray Spectroscopy, X-ray diffractometry, Compression test, and porosity measurement method.XRD analysis of synthesized whiskers confirmed the presence of HAp. SEM images showed interconnected pores in the samples, with pore sizes larger than 100µm. The compressive strengths of the samples were calculated from the stress-strain plateau average. The highest and the lowest compressive stress were calculated as 0,125 and 0,050 MPa respectively. The maximum and minimum porosities of the samples reinforced with whiskers were found to be 67,56% and 61,92%, respectively.