H_2O_2/H_2O溶液冷冻干燥制备HA多孔陶瓷

Preparation of HA Porous Bioceramic by Freezing Casting of H_2O_2/H_2O Suspensions as Template

以H2O2／H2O结晶体为模板冷冻干燥法，制备出片层孔及圆孔的双孔型羟基磷灰石（hydroxyapatite，HA）支架，观察了支架的双孔形貌，分别研究HA浆料初始固含量和孔隙率、冷冻温度和孔径尺寸之间的关系。结果表明：当初始浆料固含量在20vol％～45vol％之间变化时，可以制得孔隙率在79％～54％的多孔陶瓷支架，孔的连通性较好，支架孔隙率随着浆料固含量的降低而升高；当冷冻温度分别为-20℃、-50℃、-80℃时，平均片层间距及圆形孔孔径尺寸分别为550～1000μm，800—1000μm；450～800μm，550～750μm；330～380μm，450～500μm；支架的孔径尺寸随着冷冻温度的降低而减小，两种形貌孔道在孔壁上呈树枝状相连通，有利于细胞的攀附和生长。

Porous hydroxyapatite （HA） scaffolds were fabricated by freeze casting of suspensions containing Binary mixture of solvents （hydrogen peroxide/distilled water）, and their double holes microstructures were observed. The relationship between slurry concentration and porosity were investigated, and the influence of cooling rate on pore size was considered. The results show that the initial solid content can be transformed in the range from 20% to 45% , and the circular hole and the lamellar hole of the bioceramic scaffold of the porosity can be transformed between 79% to 54%. The scaffolds are characterized by well-defined pore connectivity. With the reduction of slurry concentration, the porosity of scaffolds gradually increases. When the freezing temperature of - 20 ℃, - 50 ℃, - 80 ℃ respectively, the average lamellar spacing and the pore size of the circular hole for scaffolds ranges from 550-1000 μm, 800-1000 μm; 450-800 μm, 550-750 μm; 330-380μm, 450-500 p.m, respectively. With the increasing of cooling temperature, the pore size gradually becomes smaller, the two channels are dendritic morphology communicated on the hole wall thus expect to be conducive to the climb and growth of cells.