African Material Science and Engineering Network A Carnegie-IAS RISE Network, University of the Witwatersrand, Johannesburg, South Africa.
University of the Witwatersrand, School of Chemical and Metallurgical Engineering, Johannesburg, South Africa.
Sci Rep. 2017 Jul 20;7(1):6046. doi: 10.1038/s41598-017-06337-2.
In this work the sintering ability of borosilicate (S53B50), borophosphate (P40B10) and phosphate (Sr) bioactive glasses was investigated. The glass powders were crushed and sintered in air at a heating rate of 10 °C/min for 2 hours at sintering temperatures between 480 °C-600 °C. The aim was to define the optimum sintering temperature prior to glass crystallization. The density of the samples was found to decrease when the temperature was increased up to 580 °C; probably due to the inhibition of the viscous flow of the particles during sintering thereby reducing the densification of the material. Such low porosity is not suitable in tissue engineering. To process highly porous scaffolds with porosity required for scaffold applicable to tissue engineering, the powders were further mixed with 60 vol.% and 70 vol.% of NH(HCO) foaming agent. Meanwhile, the density of the samples sintered with NH(HCO) was found to decrease with an increase in NH(HCO) content. This indicates an increase in porosity of the samples. The glass compositions reached an open porosity of more than 60% at the addition of 70 vol.% NH(HCO). In addition, SEM micrograph revealed large pores with good interconnection between the pores.
本工作研究了硼硅酸盐（S53B50）、硼磷酸盐（P40B10）和磷酸盐（Sr）生物活性玻璃的烧结性能。将玻璃粉末粉碎，在空气中以 10°C/min 的加热速率加热 2 小时，烧结温度在 480°C-600°C 之间。目的是在玻璃析晶之前确定最佳的烧结温度。当温度升高到 580°C 时，发现样品的密度降低；这可能是由于在烧结过程中抑制了颗粒的粘性流动，从而降低了材料的致密化程度。如此低的孔隙率不适合组织工程。为了处理具有适用于组织工程的支架所需的高多孔支架，将粉末与 60vol.%和 70vol.%的 NH(HCO)发泡剂进一步混合。同时，发现随着 NH(HCO)含量的增加，用 NH(HCO)烧结的样品的密度降低。这表明样品的孔隙率增加。在添加 70vol.%NH(HCO)时，玻璃组合物的开口孔隙率超过 60%。此外，SEM 显微照片显示了具有良好连通性的大孔。
