纳米羟基磷灰石复合陶瓷生物摩擦学行为研究

采用沉淀法合成了纳米羟基磷灰石（HA）粉体，无压烧结工艺制备了HA／PSZ陶瓷复合材料．利用材料试验分析系统（MTS）和纳米硬度分析测试系统（Triboindenter）测定了复合材料的宏观和微观力学性能，用销盘式摩擦磨损试验机考察了血浆润滑条件下复合材料的生物摩擦学性能，探讨了力学性能与摩擦学性能之间的关系．结果表明，无压烧结HA／PSZ复合陶瓷材料断裂韧性比纯HA陶瓷提高近2．7倍，弯曲强度提高近1倍．纳米硬度最高值为10．6GPa，纳米弹性模量为156．OGPa．血浆润滑条件下，HA／PSZ陶瓷和UHMWPE摩擦副的摩擦系数与HA的含量有关，UHMWPE的磨损率与HA／psz复合陶瓷摩擦副的硬度和断裂韧性存在反比关系．     

利用磷灰石实现硫化矿浮选废水回用的试验评价

出于环境的考虑，越来越多的选矿厂均利用回水以减轻废水对环境的冲击和对水资源的依赖．工业生产经验表明，回水使用量的增加会对浮选带来不利的影响，尤其是对复杂矿化矿的优先浮选．浮选选择性降低的主要原因是溶液中重金属离子对闪锌矿或黄铁矿的意外活化．本文应用微型浮选试验，吸附试验和表面测试研究了利用磷灰石来实现硫化矿浮选废水回用的可行性．试验表明，磷灰石可增强对闪锌矿的抑制而提高浮选的选择性．微型浮选和表面测试表明，磷灰石与闪锌矿竞争吸附溶液中的重金属，从而降低闪锌矿表面的重金属浓度．     

共沉淀法制备羟基磷灰石影响因素的研究

论述了共沉淀法制备羟基磷灰石粉体的过程,以Ca(OH)2和H3PO4为原料,控制适当的Ca/P比、H3PO4的滴加速率、溶液的pH值、反应温度和时间以及煅烧温度等条件,用TEM、X射线衍射仪和红外光谱仪对目标产物的结构和粒度进行了分析.结果表明,溶液在40℃下反应6h,煅烧温度为900℃,产物用无水乙醇洗涤可获得纯度、结晶度、颗粒度和分散性均较好的羟基磷灰石粉体.     

Ti-6Al-4V合金基体等离子喷涂生物活性羟基磷灰涂层的研究进展

系统阐述了在钛合金(Ti-6Al-4V)表面等离子喷涂羟基磷灰石(HA)涂层的研究进展.描述了等离子喷涂制备HA涂层的工艺过程、微观形貌和化学组成.综述几种综合性能较高的复合型涂层:HA/BG(生物活性玻璃)复合涂层,HA/ZrO2复合增强型涂层,HA/Ti涂层,HA/Ti-6Al-4V梯度涂层;并对HA涂层发展趋势进行了展望.     

Effects of pH and initial Ca2+?H2PO4? concentration on fibroin mineralization

In the present study, the effects of pH and initial Ca²⁺−H₂PO₄ ⁻ (Ca-P) concentration on fibroin mineralization were studied. The crystal growth of calcium phosphates was regulated by regenerated silk fibroin for 8 h (at pH 4.0, 7.0 and 10.0, respectively). Meanwhile, different concentrations of Ca²⁺ were employed at a certain pH value, keeping the initial Ca-P molar ratio constant at 1.67, i.e., the stoichiometry of hydroxyapatite [Ca₁₀(PO₄)₆(OH)₂, HAP]. The products were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). The results demonstrated that, compared to pH 4.0 and 10.0, pH 7.0 promoted the transformation of brushite (CaHPO₄·2H₂O, DCPD) to HAP. In the composites of mineralized fibroin, DCPD is the main inorganic phase at both relatively low and high pH, while HAP is the main inorganic phase at pH 7.0. Additionally, the initial Ca-P concentration does not affect the kind of inorganic phase in the synthesized mineralized fibroin, but induce to different contents of inorganic mineral and different morphology of DCPD at pH 4.0 and pH 10.0.     

基质调控下模板物质对羟基磷灰石矿化的作用及影响

模板法诱导生成的羟基磷灰石具有良好的生物相容性，在再生医学和骨修复领域中的应用前景广阔。讨论了有机模板调控下诱导羟基磷灰石合成的主要模板：LB膜、囊泡模板、自纽装膜。综述了合成过程中模板物质对最终形成的羟基磷灰石性质的影响。分析结果表明，模板物质的活性官能团的电负性越大，模板表面官能团的分布和官能团二维晶格与正在成核的晶体在立体化学结构上越匹配，则形成的羟基磷灰石的结构就越优良。     

RETRACTED ARTICLE: Characteristics of porous zirconia coated with hydroxyapatite as human bones

Since hydroxyapatite has excellent biocompatibility and bone bonding ability, porous hydroxyapatite ceramics have been intensively studied. However, porous hydroxyapatite bodies are mechanically weak and brittle, which makes shaping and implantation difficult. One way to solve this problem is to introduce a strong porous network onto which hydroxyapatite coating is applied. In this study, porous zirconia and alumina-added zirconia ceramics were prepared by ceramic slurry infiltration of expanded polystyrene bead compacts, followed by firing at 1500°C. Then slurry of hydroxyapatite-borosilicate glass mixed powder was used to coat the porous ceramics, followed by firing at 1200°C. The porous structures without the coating had high porosities of 51–69%, high pore interconnectivity, and sufficiently large pore window sizes (300–500 μm). The porous ceramics had compressive strengths of 5·3∼36·8 MPa, favourably comparable to the mechanical properties of cancellous bones. In addition, porous hydroxyapatite surface was formed on the top of the composite coating, whereas a borosilicate glass layer was found on the interface. Thus, porous zirconia-based ceramics were modified with a bioactive composite coating for biomedical applications.     

Template-directed one-step synthesis of flowerlike porous carbonated hydroxyapatite spheres

Flowerlike porous carbonated hydroxyapatite (CHAp) spheres were first synthesized by the template-directed self-assembly method in a high-pressure system. The product was characterized via Fourier transform infrared (FT-IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that flowerlike porous CHAp spheres were obtained, that the average granularity of porous CHAp spheres is about 20 μm, that the average aperture is about 1 μm, and that the average thickness of flakes is about 50 nm. Great amounts of OH channels, high special surface area and regular spherical shape imply potential applications.     

羟基磷灰石的形态结晶控制

对化学沉淀法制备羟基磷灰石中的制备温度、pH值、分散剂浓度、反应物浓度以及搅拌速度等因素对羟基磷灰石生长形态和结晶的影响进行了系列研究。结果表明：上述因素分别对HA的生长形态和结晶状况有不同程度的影响．通过对工艺参数的合理选择可以得到具有不同结晶状况和形态的羟基磷灰石颗粒。     

羟基磷灰水热法可控制备的研究

羟基磷灰石具有生物活性和生物相容性，因此，羟基磷灰石的合成及控制研究是当今生物材料领域研究的重要热点．水热合成法是实现高纯HAP制备的有效方法，然而，单一的合成方法很难实现HAP结构及大小有效控制．综述了近几年来水热合成法与其它方法联合实现HAP结构、大小的有效控制，以及近年来纳米羟基磷灰石制备的最新研究进展，并讨论制备条件对HAP结构及大小的影响及形成机理。