Phillips M J, Darr J A, Luklinska Z B, Rehman I
Interdisciplinary Research Centre in Biomedical Materials, Department of Materials, Queen Mary, University of London, Mile End Road, London, E1 4NS, UK.
J Mater Sci Mater Med. 2003 Oct;14(10):875-82. doi: 10.1023/a:1025682626383.
The manufacture of high-surface area, un-agglomerated nano-sized (1-100 nm) bioceramic particles are of interest for many applications including injectable/controlled setting bone cements, high strength porous/non-porous synthetic bone grafts, and the reinforcing phase in nano-composites that attempt to mimic the complex structure and superior mechanical properties of bone. In the present study, we report on the manufacture of nano-particle hydroxyapatite powders by several wet chemical methods, which incorporate a freeze-drying step. In particular, it was found that the emulsion-based syntheses yielded powders with high surface areas and small primary particle sizes. Freeze drying rather than oven drying of powders prepared by conventional wet chemical synthesis yielded a nano-sized powder with a comparatively higher surface area of 113 m(2)/g. All powders were calcined in air in a furnace at 900 degrees C to investigate the effects of synthesis method on phase purity and surface area. The materials were characterized by a range of analytical methods including Fourier-transform infrared spectroscopy employing the photo acoustic (PAS-FTIR) sampling technique, BET surface area analysis, X-ray powder diffraction (XRD), and the particles were examined using a transmission electron microscope (TEM).
高表面积、未团聚的纳米级(1 - 100纳米)生物陶瓷颗粒的制造对于许多应用都具有重要意义,这些应用包括可注射/可控凝固骨水泥、高强度多孔/无孔合成骨移植材料以及试图模仿骨的复杂结构和优异力学性能的纳米复合材料中的增强相。在本研究中,我们报告了通过几种湿化学方法制造纳米颗粒羟基磷灰石粉末的过程,这些方法都包含冷冻干燥步骤。特别地,发现基于乳液的合成方法能够产生具有高表面积和小初级粒径的粉末。通过常规湿化学合成制备的粉末采用冷冻干燥而非烘箱干燥,得到了具有相对较高表面积(113平方米/克)的纳米级粉末。所有粉末均在马弗炉中于900℃的空气中煅烧,以研究合成方法对相纯度和表面积的影响。采用一系列分析方法对材料进行表征,包括采用光声(PAS - FTIR)采样技术的傅里叶变换红外光谱、BET表面积分析、X射线粉末衍射(XRD),并使用透射电子显微镜(TEM)对颗粒进行检查。