冷冻干燥法制备的β-磷酸三钙多孔生物陶瓷支架

背景：影响冷冻干燥法制备生物陶瓷支架孔形貌和结构的因素有很多,如浆料的固含量,冷冻速率,烧结温度等。 目的：利用冷冻干燥技术结合陶瓷水基浆料,通过改变陶瓷浆料组成,制备不同形貌和孔隙率的β-磷酸三钙多孔生物陶瓷支架,并分析其影响因素。 方法：制备不同固含量和不同聚乙烯醇含量的β-磷酸三钙浆料,经冷冻、干燥及高温烧结得到多孔生物陶瓷支架。应用X射线衍射技术进行物相分析;扫描电镜观察支架截面的微观结构;阿基米德排水法测量支架材料的孔隙率。 结果与结论：X射线衍射图谱显示制备的支架材料各衍射峰强度与位置与β-磷酸三钙标准衍射谱吻合良好;浆料未添加聚乙烯醇时,多孔支架的孔径和孔隙率随着浆料固含量的增加而减小,支架由大的柱状孔和多孔的陶瓷壁组成;当浆料加入聚乙烯醇后,制备的支架由柱状孔转变为三维连通的网状孔,且随聚乙烯醇含量的增加材料的孔隙率升高。说明利用冷冻干燥法,通过控制陶瓷浆料的组成,可制备出形貌和孔隙率可控的生物陶瓷支架。

Preparation of porous bio-ceramic beta-tricalcium phosphate scaffolds by freeze-drying technique

BACKGROUND:There are many factors which can influence the microstructures and properties of bio-ceramic scaffolds prepared by the freeze-drying process, such as the slurry solid loading, freezing rate, sintering conditions, and so on. OBJECTIVE:To prepare bio-ceramic β-tricalcium phosphate (β-TCP) scaffolds with different morphologies and porosities by adjusting the content of the slurries and analyze the influence factors. METHODS:The β-TCP scaffolds with different morphologies and porosities were prepared, and then bio-ceramic β-TCP scaffolds were obtained through freezing, drying and heating. Phase analysis, microstructure of the section and porosity of bio-ceramic β-TCP scaffolds were detected by X-ray diffraction, scanning electron microscopy and Archimedes drainage method, respectively. RESULTS AND CONCLUSION:The diffraction peak position of the scaffolds was identical with the standard β-TCP; the scaffolds without polyvinyl alcohol had the macroscopic lamellar pores and porous ceramic walls, and as the solid longing of slurry was increasing, the pore size and the porosity decreased; scaffolds containing polyvinyl alcohol: the lamellar pores gradually changed into the interconnected three-dimensional reticulate pores, and the porosity was improved because of the addition of polyvinyl alcohol. It is indicated the morphology and porosity of the bio-ceramic scaffolds prepared using the freeze-drying process can be controlled by adjusting the content of the slurries.