【作者】 刘超；

【导师】 成国祥；

【作者基本信息】 天津大学 ， 材料学， 2004， 博士

【摘要】 模板法制备具有长程有序介观结构材料，是建立在分子自组织基础上的，是过程中氢键、范德华键或其他非共价键整体的、复杂的协同作用，将一个或多个物质单元自我放大以形成结构稳定的聚集体，再由一个或若干个物质单元的聚集体作为结构单元多重拷贝，使体系朝着组织层次上升和组织水平提高的方向演化，最终形成纳米结构的空间体系。该方法是有效、廉价的构筑纳米结构的方式。本文将模板法引入到具有生物相容性的羟基磷灰石的制备体系中，以十二烷基磺酸钠（SDS）为模板剂，在乙醇/水体系中制备出具有长程有序层状纳米结构的高结晶度Lα-羟基磷灰石。通过X-射线衍射（XRD）表征了长程有序纳米层状结构（2θ = 1~15o）和羟基磷灰石（2θ = 9~60o）的存在，并通过高分辩透射电镜（HRTEM）直接观测到这种纳米层状结构和单层晶片的生长方向，最终给出了该多层次结构的模型，进而采用热重分析（TGA）、红外吸收光谱（FTIR）、吸-脱附等温曲线对所制备的羟基磷灰石进行了表征。研究表明：该长程有序结构的重复周期约为3 nm，羟基磷灰石晶体在模板剂的Lα相中是沿（100）晶面和（002）晶面二维生长，而限制了与之垂直晶面的生长。模板剂用量的增加、氢氧化钠用量、原料浓度、磷源、熟化时间、陈化时间对长程有序层状介观结构的形成均有影响，乙醇/水的体积比应控制在1:1到1:2之间。采用反相悬浮分散法（W/O），以三氯甲烷、正己烷为分散介质，乙基纤维素为分散剂，Lα-羟基磷灰石/海藻酸钠水浆为分散相，后经氯化钙交联制备了海藻酸钙/羟基磷灰石复合微球。并对微球的制备条件进行了优化，对所制得的微球物性进行了测量。研究表明：对实验所用比例，乙基纤维素的用量应不少于0.2 g，适宜的分散相加入速度为25 mL/min，适宜搅拌速度为120 r/min。阿基米德法计算的50%和70%HAP复合微球比重分别为1.06和1.15 g/cm3。更多还原

【Abstract】 Materials with longrange ordered meso-structures were fabricated via templates technology based on molecular self-organization. In this process, hydrogen bond, Van der Waals bond and other noncovalent bonds cooperated as a whole, by which one or more units magnified themselves to form aggregates having steady structure, then these aggregates as structural units were multi-duplicated, which made the system’s organization evolve to higher levels, finally the system with nanostructure was formed. Templates method is an effective and cheap way to build the nanostructure. Templates method were introduced into the synthesis of hydroxyapatite (HAP, Ca10(PO4)6(OH)2), which exhibits strong affinity to host tissue, to form hierarchy structure. Calcium hydroxyapatite with longrange ordered lamellar nanostructure and well-crystallized lattice, noted with Lα-HAP, was fabricated via sodium dodecyl sulfonate (SDS, C12H25SO3Na) as templates in ethanol-water solvent. The longrange ordered lamellar nanostructure was characterized by X-ray diffraction (XRD) in the small angles (2θ = 1~15°) and HAP phase in 9~60°. The longrange ordered lamellar nanostructure and the orientation of the growth of crystal were observed by High Resolution Transmission Electron Microscopy (HRTEM). Based on these, the model of this hierarchy structure was given. Followed, the hydroxyapatite was characterized by thermogravimetry (TGA), Fourier transform infrared spectroscopy (FTIR) and N2 adsorption and desorption isotherms. The result showed that the periodicity of the lamellar structure was about 3 nm. The crystal grew along the crystal faces (100) and (002) in the Lα phases, but the growth of perpendicular face was restricted by the templates. Template content, NaOH content, concentration of materials, phosphates resource, riping time and aging time have influence on the formation of longrange ordered lamellar nanostructure. The volume ratio of ethanol and water is 1:1 to 1:2.Calcium alginate/Lα-Hydroxyapatite composite microspheres were fabricated via inverse suspension (W/O) with chloroform and hexane as dispersed phase, ethyl cellulose as disperser, mixture of Lα-hydroxyapatite and sodium alginate solution as <WP=5>dispersing phase, finally, the microspheres were crosslinked with calcium chloride solution. The preparation conditions were optimized. The physical appearances of the microspheres were characterized. It was shown that content of ethyl cellulose should not less than 0.2 g in this experiment; the suitable adding speed of dispersed phase and the speed of stirring are about 25 mL/min and 120 r/min, respectively. The specific gravity of the microspheres containing 50% and 70% HAP is 1.06 and 1.15 g/cm3, respectively, evaluated by Archimedean method.更多还原