Effect of nanosilica addition on the physicomechanical properties, pore morphology, and phase transformation of freeze cast hydroxyapatite scaffolds

摘要

Freeze casting technique is a simple and effective method for the fabrication of porous ceramic structures. The objective of this work is to study the production and characterization of hydroxyapatiteanosilica (HASiO_2) scaffolds fabricated through this method. In the experimental procedure, the solidified samples were prepared by slurries containing different concentration of HA and nSiO_2 followed by sintering procedure at 1200 and 1350 °C. The phase composition, microstructure, and compressive strength of the scaffolds were characterized by X-ray diffraction, scanning electron microscopy, and mechanical strength test. It was found that the porosity of the scaffolds was in the range of 30–86.5 % and the value of compressive strengths lied between 0.16 and 71.96 MPa which were influenced by nSiO2 content, cooling rate, and sintering temperature. With respect to porosity, pore size, and compressive strength, the scaffolds with 5 % nSiO_2, the cooling rate of 1 °C/min and the sintering temperature of 1350 °C showed preferable results for bone tissue engineering applications.