Yao Xiumin, Tan Shouhong, Jiang Dongliang
The State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050.
J Mater Sci Mater Med. 2005 Feb;16(2):161-5. doi: 10.1007/s10856-005-5901-2.
Porous hydroxyapatite (HAp) ceramics with controlled pore characteristics were fabricated using slip casting method by mixing PMMA with HAp powder. The optimum conditions of HAp slip for slip casting was achieved by employing various experimental techniques, zeta potential and sedimentation, as a function of pH of the slips in the pH range of 4-12. HAp suspensions displayed an absolute maximum in zeta potential values and a minimum in sedimentation height at pH 11.5. The optimal amount of dispersant for the HAp suspensions was found at 1.0 wt% according to the viscosity of 25 vol% HAp slurry. The rheological behaviour of HAp slurry displays a shear-thinning behavior without thixotropy, which is needed in slip casting processing. The pore characteristics of sintered porous hydroxyapatite bioceramics can be controlled by added PMMA particle size and volume. The obtained ceramics exhibit higher strength than those obtained by dry pressing.
通过将聚甲基丙烯酸甲酯（PMMA）与羟基磷灰石（HAp）粉末混合，采用注浆成型法制备了具有可控孔隙特征的多孔羟基磷灰石陶瓷。通过采用各种实验技术，即ζ电位和沉降法，研究了在4-12的pH范围内，作为泥浆pH值函数的HAp泥浆注浆成型的最佳条件。HAp悬浮液在pH 11.5时ζ电位值出现绝对最大值，沉降高度出现最小值。根据25 vol% HAp浆料的粘度，发现HAp悬浮液的最佳分散剂用量为1.0 wt%。HAp浆料的流变行为表现出剪切变稀行为且无触变性，这是注浆成型工艺所需要的。烧结多孔羟基磷灰石生物陶瓷的孔隙特征可通过添加的PMMA粒径和体积来控制。所获得的陶瓷比通过干压获得的陶瓷具有更高的强度。
