本论文利用简单的沉淀方法，控制羟基磷灰石的成核和生长，原位制备具有独特显微结构特点的功能性纳米羟基磷灰石，并使羟基磷灰石具有优异的物理和化学性能。第一章为前言，介绍了纳米羟基磷灰石的性质、制备工艺以及生长的原理、应用和功能性纳米羟基磷灰石的合成方面的研究现状与发展。第二章，首先利用简单的沉淀法合成出高纯度和结晶度好的羟基磷灰石。并且，采用聚丙烯酸(PAA)为有机质，原位合成针状的纳米羟基磷灰石，有机质与氢氧化钙发生化学作用生成有机质钙，改变了羟基磷灰石的表面性质。与不加入有机质制备的羟基磷灰石相比，分散性得到了大大提高，能稳定、均匀地分散在水中，使得其作为生物陶瓷应用有了更好的前景。第三章，首次采用聚乙烯吡咯烷酮(PVP)为有机质，沉淀法原位制备棒状纳米羟基磷灰石，PVP对产物的颗粒尺寸控制和表面性质起到了双重作用。对其进行了生物方面的性能测试，此方法制备的羟基磷灰石能够实现跨膜，进入细胞中，并且对癌细胞有一定的抑制作用，为其在生物纳米领域开拓了新方向。第四章，采用自制的纳米碳酸钙为钙源，通过对反应条件的控制，在无任何有机质以及金属离子添加的条件下，首次成功自组装成球形羟基磷灰石，为制备球形羟基磷灰石开辟了一种新方法。第五章，采用碳酸钙作为钙源，无任何有机质以及聚合物的添加，分别加入无机元素硅、铝，首次成功制备了掺杂无机元素的纳米硅酸羟基磷灰石和具有孔隙结构的花状微球。第六章，以中空球形的碳酸钙作为模板以及反应物，采用简单的化学沉淀法，首次在无任何添加物的条件下制备出羟基磷灰石的中空微球。本论文获得了一些创新性的研究成果，在羟基磷灰石的制备和性质研究中引入新的思路，具有广阔的工业应用前景，对羟基磷灰石的生长机理以及实际应用具有指导意义。

 With the development of science and technology, mew materials are used widely in all areas of the society. The application of biological material has got unprecedented attentions. As the most representative biomaterials, hydroxyapatite (HAP) has been of great interest in the fields of materials and neoteric biomedicine engineering science derived from the most similar composition and crystal structure with a basic mineral of phosphate ores in bones and teeth of living vertebrates. HAP has attracted extensive attention in the field of bone tissue engineering as implants or as coatings on prostheses owing to its excellent bioactivity, biocompatibility, osteoconductivity, chemical and physical stability. However, the artificially synthesized HAP materials for the repairing of bone defects are greatly restricted to apply in the load-bearing situation because of its low dense, low strength and poor mechanism compared with natural bone. In order to solve these problems, many investigations have been carried on such as coating materials, composite materials, and nanomaterials. Some research revealed that properties of HAP are largely dependent on their micro structural features, such as particles size, degree of particles size agglomeration and sintered densities. Compared with pure hydroxyapatite, a biological apatite (like in bone) is non-stoichiometric and contains several different substituents in its structure, mainly carbonate (some percent) and other elements in traces like Mg²⁺, Na⁺, Fe²⁺, Sr²⁺, Pb²⁺, HPO₄²⁻, F⁻, Cl⁻. Therefore, the preparation of fine, single distribution and stable HAP particle is the most important step in achieving a highly sintered ceramic material with desirable microstructure. In this paper, via precipitation method, to synthesize hydroxyapatite nanoparticles (nano-HAP) in a systematic and all-round way, and basically realized the controllability of the sizes and appearances of the as-synthesized nano-HAP. Some mechanism of HAP growth was simply discussed. The main research works were as follows: The high purity and good crystallinity HAP nanorods have been synthesized by precipitation method in aqueous phase. The as-synthesized HAP nanorods had a diameter of 30 nm, and a length of 100 nm. We synthesize Polyacrylicacid (PAA) as organic substrate which can make interfacial recognition of molecules with mineral. In order to obtain stable nano-scaled HAP suspension, sodium PAA, a widely used additive for food and medical, was applied in this study. The effects of the amount of PAA and ultrasonic time on the dispersion stability of nano-scaled HAP were studied by the images absorbance. The dispersion mechanism was preliminarily discussed as well. The experimental results showed that PAA greatly increased the absolute value, which indicated PAA could effectively improve the dispersion stability of the nano-scaled HAP powder in water. The enhancement mechanism of PAA might be resulted fromthe electrostatic stabilization and steric stabilization. The organic substrate shields the solid surface through PAACa, which decreasing dramatically its surface energy and hence facilitate the dispersion of the filler in a water. We found that Polyvinylpyrrolidone (PVP), as a template, could control the formation of hydroxyapatite nanorods by a one-step precipitation, This preparation has been properties of simple process and low cost, furthermore, larger in the concentration of PVP is, the better the dispersive properties is. From the results of the X-ray diffraction and transmission electron microscopy, it can be seen that the simple method is an effective way to obtain the single crystal HAP nanorods with mono-dispersion and narrow-size distribution in diameter. All these results showed that PVP really played an important role in the formation of HAP nanorods, which is perhaps relative to its amounts of amide groups and molecular structure. Because amide groups of PVP combined with a hydrated calcium ions in alkaline solution. Prickly carbonated hydroxyapatite (CHAP) spheres have been obtained via a facile template-free self-assembly method at 60 ℃ with self-made cubic CaCO₃ and Na₂HPO₄ as reactants. X-ray diffraction results of the products revealed CHAP could be successfully prepared with high crystallization in a short reaction time. A nucleation mechanism was proposed according to the result of characterizing the resultant powders and analyzing the growth process. And we believe that the self-made CaCO₃ particles play an important role in the template-free synthesis of prickly spheres. The silicon-substituted hydroxyapatite (SiHAP) nanoparticles were first synthesized by precipitation method. SiHAP mean that silicate is substitute for phosphates and incorporates into the HAP lattice, can significantly increase bioactivity of HAP. Flowerlike porous HAP spheres were first synthesized by the template-free precipitation method. The product was characterized via fourier transform infrared, X-ray diffraction and scanning electron microscopy. The results showed that flowerlike porous HAP spheres were obtained, that the average granularity of porous HAP spheres is about 3 pm, that the average aperture is about 200 nm, and that the average thickness of flakes is about 30 nm. Great amounts of OH channels, high special surface area and regular spherical shape imply potential applications. Without any organic additives and metal ion, hollow hydroxyapatite microspheres were successfully synthesized using hollow CaCO₃ microspheres and Na₂HPO₄ as reactants. The hollow microspheres were characterized by scanning electron microscopy, field emission scanning electron microscope and X-ray diffraction. The results show that the as-prepared HAP was hollow microspheres with diameter of 2-4 μm, which are composed of many needle-like particles, with the size of 40-60nm in diameter and 80-200 nm in length. The effects of the synthesis conditions, such as reaction temperature and reaction time, were studied. Furthermore, the reaction temperature has important influence on morphology of the hollow HAP microspheres. Based on this result, the formation mechanism of hollow HAP microspheres was discussed preliminarily. In this thesis, we attempted a biomimetic method to obtained nano-HAP with special properties, introduced a novel ideal to synthesis nano- HAP. In-situ technique employed during preparation process, which introduced functional groups upon the surface of nano-HAP overcoming the agglomeration of nanoparticles. For the benefits of simple, uninterrupted and inexpensive, this innovatory technique has potential use in application and guide meaning in large-scale industrialization manufacture of nano-HAP. Keywords: hydroxyapatite, biomaterials, nanoparticles, precipitation method