Properties of Nanostructured Hydroxyapatite Prepared by a Spray Drying Technique.
Properties of Nanostructured Hydroxyapatite Prepared by a Spray Drying Technique.
复制标题
DOI：
10.6028/jres.109.041
复制
发表时间：
2004-11
影响因子：
1.5
通讯作者：
Hockey B
中科院分区：
文献类型：
--
作者：
Chow LC;Sun L;Hockey B
在以前的研究中，纳米羟基磷灰石（HA）颗粒是通过溶胶或沉淀法制备的，其中产品被水或非水液体洗涤以去除杂质或不需要的成分。众所周知，洗涤可以改变结晶颗粒的表面。本研究评估了用喷雾干燥方法制备的纳米透明质酸材料的性能，在这种方法中，透明质酸产品在形成后不暴露于任何液体中。喷雾干燥装置由一个喷嘴组成，该喷嘴将酸性磷酸钙溶液以细雾的形式喷射到流过加热玻璃柱的过滤空气流中。当雾到达柱的末端时，水和挥发性酸被蒸发掉，细颗粒被静电除尘器收集起来。粉末x射线衍射图表明材料是无定形的，在30.5°2θ处有一个单一的宽峰。然而，高分辨率透射电镜分析表明，其中一些颗粒的尺寸为5 nm，具有有序的HA晶格条纹。小面积衍射图表明HA。傅里叶转移红外光谱显示了少量HPO42−的典型HA模式。纳米HA的热力学溶解度积为3.3 × 10−94，而宏观尺度结晶HA的热力学溶解度积为1 × 10−117。这些结果表明，喷雾干燥技术可用于制备纳米尺寸的透明质酸晶体，其物理化学性质与体积尺寸的透明质酸晶体有显著不同。
In previous studies nano sized hydroxyapatite (HA) particles were prepared by solgel or precipitation methods, in which the products were washed by aqueous or non-aqueous liquids to remove impurities or undesired components. The washing is know to modify the surfaces of the cystalline particles. This study evaluated properties of nano HA materials prepared by a spray drying method in which the HA product was not exposed to any liquid after its formation. The spray drying apparatus consisted of a nozzle that sprayed an acidic calcium phosphate solution in the form of a fine mist into a stream of filtered air flowing through a heated glass column. The water and volatile acid were evaporated by the time the mist reached the end of the column, and the fine particles were collected by an electrostatic precipitator. Powder x ray diffraction patterns suggested the material was amorphous, exhibiting a single broad peak at 30.5° 2θ. However, high resolution transmission electron microscopic analysis showed that the particles, some of which were 5 nm in size, exhibited well ordered HA lattice fringes. Small area diffraction patterns were indicative of HA. Fourier transfer infrared spectroscopy showed patterns of typical of HA with small amounts of HPO42−. The thermodynamic solubility product of the nano HA was 3.3 × 10−94 compared to 1 × 10−117 for macro scale crystalline HA. These results showed that a spray drying technique can be used to prepare nanometer sized crystalline HA that have significantly different physicochemical properties than those of its bulk-scale counterpart.