冷冻干燥法制备层状多孔羟基磷灰石支架过程中的溶剂升华行为(英文)

Solvent Sublimation Behavior in Freeze Drying Method for Lamellar Porous Hydroxyapatite Scaffold

采用水基羟基磷灰石(hydroxyapatite,HA)浆料,经冷冻干燥和烧结工艺(1 250℃烧结3 h)制备了层状多孔HA支架。研究了冷冻温度、干燥压力和干燥温度对水基HA浆料中溶剂升华行为的影响。结果表明:随着冷冻温度的降低,多孔HA支架的层间距逐渐减小,支架的升华时间增加;由于样品的干燥过程同时受到传热和传质的影响,随干燥压力的增加,干燥时间先降低后升高,同时干燥时间也随干燥温度的增加而降低,最终优化得到的最佳冷冻干燥工艺参数(压力和温度)分别为40 Pa和5℃,为冷冻干燥法制备多孔陶瓷过程中干燥时间的预测提供了依据。

Lamellar porous hydroxyapatite（HA） ceramic scaffolds were fabricated by freeze drying from aqueous HA slurries and sintered at 1 250 ℃ for 3 h.Effects of freezing temperature,drying pressure and drying temperature on the solvent sublimation be-havior were investigated.The average lamellar spacing of porous HA ceramic scaffolds decreases and the sublimation time increases with the decrease of freezing temperature.The sublimation time firstly decreases and then increases with the increase of the drying pressure due to the effect of heat and mass transfer in the drying process of HA scaffolds.The sublimation time decreases with in-creasing drying temperature.The optimum parameters in the freeze drying are drying pressure of 40 Pa and drying temperature of 5 ℃.The sublimation time of porous ceramics could be predicted based on the freezing temperature and drying parameters in the freeze drying.