A comparative study of physicomechanical and in vitro bioactivity properties of β-wollastonite/cordierite scaffolds obtained via gel casting method

Abstract

This study aimed to fabricate and characterise β-wollastonite/cordierite scaffolds synthesised via gel casting method, with different β-wollastonite and cordierite powder (wt.%) ratios of 100:0 (W), 70:30 (W7C3), 50:50 (W5C5), 30:70 (W3C7), and 0:100 (C). β-Wollastonite was synthesised by wet-milling silica and calcium oxide, and then, sintered at 950 °C for 3 h. Cordierite was synthesised using silica, magnesia, and alumina as the raw materials through the quenching method after the ingredients have been melted at 1400 °C and sintered at 980 °C for 2 h. Next, the effect of cordierite composition on the phase composite, and microstructure, as well as the physicomechanical and in vitro bioactivity properties of β-wollastonite/cordierite scaffolds were thoroughly investigated. The sintering linear shrinkage for all scaffolds was observed at 5.35%–15.25%, while bulk density was increased from 1.30 to 1.62 g/cm3. The X-ray diffraction analysis showed that all scaffolds, except the 100% cordierite (C), contained hydroxyapatite phase after being immersed in simulated body fluid (SBF). An apatite layer can be seen on the surface of the W, W3C7, W5C5, and W7C3 scaffolds. Scaffolds with porosities ranging from 70.3% to 53.3% showed compressive strengths ranging from 4.34 to 11.59 MPa. After one week of immersion in SBF, the compressive strength of the scaffolds has decreased dramatically (up to 75%). It was concluded that the W3C7 scaffolds have the best composition for fabricating porous scaffolds.