Papers by Author: P. Sooksaen

Abstract: Apatite-wollastonite bioactive glass-ceramic scaffolds were fabricated from the SiO₂-CaO-P₂O₅ MgO-CaF₂ glass system by controlled crystallization between 800 and 1200C of the melted and quenched glass powder. Wood powder with controlled particle size distribution was used to obtain bioactive glass-ceramic scaffolds by burning-out process during crystallization of glass. Bioactive phases of apatite and wollastonite were found in all crystallized samples but the relative amount depended on the crystallization temperature. The bioactivity was studied via simulated body fluid (SBF) solution from 2 to 12 weeks. After soaking for 2 weeks, a porous hydroxyl-carbonate apatite (HCA) layer formed at the SBF-glass ceramic interface and the HCA layer thickness increased at longer soaking periods. This study led to a promising platform for hard tissue engineering.

Abstract: Bulk crystallization of B₂O₃-SiO₂-Al₂O₃-BaO-MgO glass system was investigated. Controlled heat treatment process was carried out between 900 and 1200°C to form glass-ceramics. Phase evolution in the crystallized glasses was studied by X-ray diffraction. Microstructures of the chemically etched surfaces were revealed by scanning electron microscope and micro-hardness was measured by Vickers hardness tester. High aspect ratio of aluminium borate whiskers were in the nano to micro regime and dispersed within the residual glass matrix. Whiskers had different sizes and compositions depending on the heat treatment temperature, which affected the surface hardness of the glass-ceramics. In general, increasing heat treatment temperature led to an increase in crystal size and length as well as the surface hardness (4.8 to 5.5 GPa). The whisker crystals oriented uniformly within the residual glass matrix leading to interlocking microstructure. The synthesized glass-ceramics in this study can be applied as machinable materials in various industries because their microstructures can resist microcracking and hence increase fracture toughness.