纳米羟基磷灰石的表征及其对肝癌抑制作用的研究

利用化学方法辅助超声制备出稳定单分散的羟基磷灰石(HAP)纳米粒子体系.应用原子力显微镜(AFM)、粒径电位仪对HAP纳米粒子进行表征;采用形态学观察和MTT比色法研究HAP纳米粒子对细胞系Bel-7402人肝癌细胞的作用;从单细胞荧光元素微区分析、超微结构及细胞周期的改变研究其作用机理.实验结果表明:HAP纳米粒子在体外对Bel-7402人肝癌细胞具有明显的抑制作用,通过进入到癌细胞内,阻滞细胞周期的进展,使细胞在G1期堆积,导致癌细胞胀亡.     

间歇式溶液添加法制备片状HAP

在研究HAP的表面结构、表面电荷性能、表面吸附特性的基础上，对现有的水溶液制备HAP的方法进行改进，不用通常的缓慢而持续滴加反应溶液的方法，而采用间歇式反应溶液滴加法，再通过控制溶液的pH值（7.0-7.5)以及反应溶液的添加次序等，最终得到片状HAP晶体。用X－射线衍射分析，红外光谱分析，扫描电镜形貌观察，对片状HAP的性能及结构进行分析，并对Cl^-的作用机理进行了初步探讨。     

Electronic microscopy analysis of HAP single crystals prepared by hydrothermal method

Hydroxyapatite(HAP,Ca10(PO4)6(OH)2in one of the quite important bone implant materials.The hydroxyapatite crystals were synthesized under hydrothermal condition.The specimen was verified to be HAP crystal by the X-ray powder diffractometry(XRD).Then the specimen was distinguished single crystal from polycrystal by the use of the transmission electron microscope(TEM).The diffraction pattern of the specimen is neatly affanged diffraction spots,that verified the crystals were single crystals.The interplanar distance d calculated from diffraction spot is coincided with that of HAP‘s JCPD card.Moreover,crystal face angles calculated from crystal face index are coincided with the values by measuring on the pattern.The HAP crystals are needle-like in shape with about 3μm in diameter and 180μm in length.Most of the crystals are whiskers.Their length/diameter ratio ranges from 40 to 100.The average ratio is about 60.     

SiO2包覆的羟基磷灰石纳米粒子的制备与性能研究

采用正硅酸乙酯(TEOS)水解法在羟基磷灰石粉体表面包覆SiO2进行表面改性,并通过扫描电镜(SEM)、透射电镜(TEM)、X射线衍射(XRD)、红外(FT-IR)、zeta电位和沉降实验等对样品的晶体结构、颗粒形貌进行了表征,结果表明涂层厚度约为3nm,包覆后的纳米粒子在水溶液中的胶体稳定性提高了5倍,SiO2在羟基磷灰石表面的吸附符合异质凝结机制。     

纳米HAP粒子在水介质中的分散稳定性研究

在水分散体系中采用化学沉淀法制备纳米羟基磷灰石（Hydroxyapatite，HAP）粒子，研究了分散介质pH值、稳定剂或表面改性剂及其分子量等因素对纳米粒子粒径及分散稳定性的影响，重点讨论了阴离子表面活性剂PAA-Na（聚丙烯酸纳）对纳米HAP溶胶分散稳定性的影响。同时对纳米HAP溶胶分散稳定性机理在理论上作了探讨。     

通过仿生法在硅橡胶表面制备磷灰石薄膜的研究

用CaCl2的乙醇溶液和K2HPO4溶液对硅橡胶进行预处理,将处理过的硅橡胶分别浸渍于模拟体液和钙磷饱和溶液中来制备磷灰石薄膜.利用薄膜X射线衍射、红外吸收光谱和扫描电子显微镜对形成的薄膜进行了表征.结果表明,分别在模拟体液中7d和在钙磷饱和溶液中5d后,硅橡胶表面形成了一层磷灰石薄膜;在模拟体液中的薄膜表面呈网状并分布有许多球状晶粒,在钙磷饱和溶液中的薄膜为结晶良好的片状晶体.     

热轧厂层流冷却系统存在的问题及改造

分析了武钢热轧厂层流冷却系统存在问题,采用调节水箱与调速水泵运行相结合的改造方案,并解决了变频电机轴承承载能力不够问题,从而满足了生产需要,提高了产品质量,降低了能耗。     

影响纳米羟基磷灰石溶胶在水介质中分散性能的因素

目的：探讨影响纳米羟基磷灰石溶胶分散性能的因素。方法：以水分散体系下，采用化学共沉淀法制备的纳米HAP，研究了反应介质pH值、稳定剂或表面改性剂等因素对纳米粒子粒径及分散稳定性的影响。结果：调节介质的pH值，使颗粒间处于较高的静电效应，在此条件下加入表面活性剂，使颗粒间又具有空间位阻稳定效应，空间位阻稳定效应可阻止颗粒间的团聚。结论：通过优化实验条件可制得高度均匀分数状态纳米羟基磷灰石溶胶。     

可降解多孔β-磷酸钙生物陶瓷的制备研究

本文采用湿法制备β-磷酸三钙（β-TCP）粉末，以玻璃为黏结剂，经高温烧结后，添加造孔剂混合后热压铸成型，经过高温处理，制备出可生物降解的β-TCP多孔材料。经X-射线衍射和扫描电镜形貌分析，证明材料主晶相是β-TCP，材料内部有大量连通的均匀微孔。溶解测试表明材料具有一定的溶解性。材料的制备工艺可实现规模化生产。     

Preparation and Characteristics of Hydroxyapatite Whiskers by Homogeneous Precipitation Method

Hydroxyapatite whiskers were prepared by the homogeneous precipitation method. Soluble calcium ion and phosphate ion were used as initial materials, they were refluxed respectively at 85℃ , 90℃ and 95℃ for various lengths of time. A proper precipitation agent was selected to control the releasing speed of ions in the system; it induced the hydraxyapatite crystal to grow in a desired way. The pH values of each solutions were measured continuously during the reaction. After the reaction, the products were characterized by X- ray powder dif-fractometry (XRD), scanning electron microscopy ( SEM) and infrared spectroscopy (IR). It is shown that long hydroxyapatite whiskers were obtained under the conditions of 95℃ - 48h and 90℃ - 12h, 85℃ - 120h.