【作者】 陈菲；

【导师】 林昌健；

【作者基本信息】 厦门大学 ， 物理化学， 2004， 博士

【摘要】 纳米生物材料是当今材料和医药领域的一个重要组成部分和发展方向，纳米材料将可能成为21世纪生物医学材料的核心。自然骨是由纳米羟基磷灰石(Ca₁₀（PO₄）₆（OH）₂，HAp)晶体和胶原蛋白组成的复合材料，制备与自然骨性能接近的纳米生物材料是人们不懈努力的目标。人工合成的羟基磷灰石材料与人体组织具有良好的相容性，并能与骨组织形成骨性结合，但材料本身的脆性使其不适用于人体强负载部分。本论文的目的是研究在金属钛表面涂覆纳米羟基磷灰石膜层的制备方法和性能，以期获得具有优良力学性能和生物性能的纳米合生物材料。 通过实验比较了沉淀法、沉淀法结合水热处理和溶胶—凝胶法合成纳米HAp粉末的优缺点。结果表明温度对反应产物的形貌有较大的影响。水热处理可促进纳米HAp晶体在c—轴方向的生长，这与自然HAp晶体的生长是一致的，同时晶体形态的生长较完整。溶胶—凝胶法因需要煅烧过程，易造成粉末团聚，难以得到纳米HAp粉末。成功的将溶剂替换干燥技术扩展应用于纳米HAp粉末的干燥，所得粉末疏松，团聚少。 制定沉淀法结合水热处理合成纳米羟基磷灰石的工艺，设计了电加热压力反应釜，实现了纳米羟基磷灰石粉末的宏量合成。结果表明，宏量合成获得的HAp纳米粉末尺寸分布均匀，成分纯，采用所建立的工艺条件和合成设备，可实现纳米HAp粉末安全、快速、宏量的生产。 分别以共沉淀法和包覆法制备了纳米羟基磷灰石／壳聚糖（HAp／CTS）和纳米羟基磷灰石／聚乳酸（HAp／PDLLA）的复合材料。粉末尺寸分布均匀，团聚轻微，微观结构均一，克服了传统浇注法制备的无机／有机复合材料微观结构不均匀，相间结合不牢的缺点。此材料可用于制备各种形状的植入体。厦门大学理学博士学位论文 建立了电泳沉积法（EPD）在钦基表面沉积均匀的纳米轻基磷灰石涂层的方法.为了克服传统EPD工艺烧结温度高，结合强度不如等离子喷涂工艺等缺点，进行了一系列的实验探索和工艺改进。首次采用弱酸性溶剂，乙酸配，为分散介质进行纳米HAp涂层的电泳沉积，避免了在体系中引入酸液而在沉积过程中因水的分解产生气体.结果表明，采用纳米HAp粉末可以明显降低涂层的烧结温度，比常用的温度（1 000℃）约低200℃.经烧结处理，涂层结构均匀、无裂缝，能够保持纳米结构。对钦进行一定的表面氧化和化学刻蚀处理后，钦表面布满腐蚀小孔，作为支架，实现了HAp涂层和金属基底的机械互锁，改善了涂层的力学分布，增强了HAp涂层与基底的结合力。此外，钦表面氧化和化学刻蚀处理，使得表面形成一定厚度的和稳定的TIOZ薄层.石02具有介于钦和HAp之间的热膨胀系数，起到过渡层的作用，从而可降低烧结后涂层和基底之间的残余应力，减少 HAp涂层裂纹的发生，进一步改善了涂层的结合性能。EPD法制备纳米HAp涂层与钦基底的结合强度可达18士2.SMPa，杨式模量和硬度分别为40.6和0.42 GPa。 探索了以骨髓干细胞体外培养实验，对钦基表面沉积的纳米轻基磷灰石EPD涂层的生物性能进行初步评价。比较实验结果表明，细胞在材料表面和周围生长良好，特别是在纳米HAp EPD涂层表面的细胞增殖最快，证明钦基表面沉积的纳米轻基磷灰石EPD涂层的生物相容性和生物活性最好，其余依次为常规尺寸（微米尺寸）的HAp涂层，纯钦板。以湿法制备的HAp粉末与烧结后的HAp粉末相比，在形貌和晶体结构方面都更接近于自然磷灰石;纳米经基磷灰石EPD涂层的大比表面积和良好的仿生特性，有利于蛋白质等生物大分子与材料的相互作用，促进细胞的吸附和增殖，因此表现出良好的生物相容性和生物活性。更多还原

【Abstract】 Nano biomaterials become a most important branch in the field of materials and medicine, and they are recognized as a nuclear material in biomaterial in the 21th century. Natural bone is a composite material made of nano hydroxyapatite (Ca10(P04)6(OH)2. HAp) crystals and collagen fibers. Great attempts have been made to prepare the biomaterials with similar composition, structure and properties to the natural bone. Synthetical HAp materials show good biocompatibility and have the ability to form osteointegration. But due to its brittleness, pure HAp material is not suitable to be used for bone implant materials. The motivation of this work is to develop novel techniques to prepare riano HAp coating on titanium substrate, to acquire composite nano biomaterials with an excellent biocompatibility and bioactivity and mechanical properties.The HAp nano powder was synthesized by co-precipitation followed by hydrothermal treatment. Reaction temperature had great effect on the powder morphology. Through hydrothermal treatment the crystal growth of HAp in c-axes direction was enhanced, which was similar to the natural HAp crystals. Hydrothermal treatment also helped the growth of crystals with uniform size. Sol-gel method was also used to synthesize HAp powder. In this process, calcining was needed to complete the reaction, but high temperature caused the aggregation of powder and the powder size might be beyond nano scale.According to the flow and technical parameters of the synthesis of nano HAp powder, a reactor was designed to achieve a large-scale preparation of HAp under certain temperatureand pressure. It was shown that the HAp nano powder synthesized by this technique was of uniform structure and perfect crystalline. It is a safe, quick method to prepare large-scale HAp nano powder.The HAp/CTS and HAp/PDLLA nano composite powder were synthesized by co-precipitation and surface coating, respectively. The composite powder had uniform size and microstructure, which may avoid from some technical problem, such as, uneven microstructure, insufficient bonding between different phases, etc, by the traditional slip-casting method. This kind of nano HAp composite powder is suitable for preparing block materials or implant devices with various shapes in the clinical applications.Titanium and its alloy are used widely as bone implant materials due to their excellent mechanical properties and biocompatibility. The HAp coating on titanium surface can further improve the affinity between cells or biomolecules and implant surfaces, thus the bioactivity, biocompatibility and utility of biomaterials will be enhanced. In this work, the HAp nano coating on titanium surface was prepared in order to combine the bioproperties of HAp bioceramic and the excellent mechanical properties of titanium.A uniform HAp nano coating was formed on the titanium substrate by electrophorectic deposition (EPD). To overcome the shortage of traditional EPD process, such as relatively high sintering temperature, lower bonding strength than that of the coating formed by plasma spraying, etc., some technical improvements had been done. For the first time acetic anhydride was used as solvent to disperse HAp particles, which avoided adding acid solution into the suspension and the gas formed by the electroanalysis of water. The results indicated that using nano HAp powder to form a EPD coating on titanium substrate could decrease the sintering temperature as low as 800 "C, which was 200 "C lower than the temperature usedin general EPD coatings ( 1000). The coating was uniform, maintained nano structure and showed no cracks after sintering at 800 . After surface oxidation and chemical etch, a distribution of small pits acting as scaffold was formed on Ti surface. As a result, mechanical interlocking was formed between coating and substrate, which improved the bonding between coating and substrate. In the other hand, both Ti-OH groups formed by etching and the strong oxidation tendency of concentrated H2SO4 leaded to the formation of a thin TiO2 la更多还原