【作者】 陈福平；

【导师】 胡巧玲；

【作者基本信息】 浙江大学 ， 材料学， 2006， 硕士

【摘要】 磁性材料可以在外加磁场的用用下产生力响应和热响应,这是本文工作的思想来源。本文在实验室原有工作的基础上,采用原位沉淀和原位复合对磁性壳聚糖复合材料的制备进行了研究,成功制备出了目标材料,并且受到骨结构的启发,采用外加磁场对壳聚糖基质中的纳米颗粒分布进行了调控。 1.原位复合法制备壳聚糖/四氧化三铁纳米复合材料 以壳聚糖膜为模板、NaOH溶液为凝固液,通过配制磁性壳聚糖前驱体溶液,然后采用原位复合法制备出磁性壳聚糖棒材。X射线粉末衍射测试结果证实了原位复合法制备出磁性壳聚糖棒材中Fe₃O₄的生成,同时磁性能测试结果表明制备的磁性壳聚糖棒材具有超顺磁性,能在理论上满足磁性生物材料对磁性的要求。从数码照片可以看出棒材具有宏观层状结构,同时扫描电镜测试结果表明复合棒材也具有微观层状结构,详细讨论了层状结构形成的机理。并且可从透射电镜照片得出生成的Fe₃O₄颗粒的粒径大小约为15nm,在壳聚糖基质中分布均匀。力学性能测试表明原位复合法制备出壳聚糖/四氧化三铁棒材的棒材弯曲强度达到98.8MPa（100/3,质量比）,与纯壳聚糖棒材相比强度没有下降。 2.原位沉淀法制备四氧化三铁/羟基磷灰石/壳聚糖棒材 通过化学沉淀法制备四氧化三铁/羟基磷灰石,然后以壳聚糖为基体,利用原位沉淀法将Fe₃O₄/HA与壳聚糖复合,制得四氧化三铁/羟基磷灰石/壳聚糖复合材料。经X射线粉末衍射测试、粒径分布和磁性能测试,结果表明了四氧化三铁/羟基磷灰石复合物的生成。系统研究了四氧化三铁/羟基磷灰石/壳聚糖棒材力学性能的影响因素,最终确定四氧化三铁与羟基磷灰石质量比为3:17,无机物与壳聚糖质量比为9:91时,棒材的力学性能最优,弯曲强度可达到87.0MPa,弯曲模量1.57GPa。 3.原位复合法制备壳聚糖/羟基磷灰石/四氧化三铁纳米复合材料 采用原位复合法成功制备出壳聚糖/羟基磷灰石/四氧化三铁纳米复合材料,X射线粉末衍射测试结果表明生成的无机物为四氧化三铁和羟基磷灰石,磁性能测试结果表明该复合材料具有超顺磁性,饱和磁化强度能达到49.6emu/g,经透射电镜观察证实了生成的无机颗粒大小均一,粒径大约为长30nm,宽20nm,且在基质中分布均匀无明显的团聚现象。从扫描电镜照片可以得出制备的复合材料更多还原

【Abstract】 Under the effect of the extra magnetic field, magnetic materials can form the mechanical effect and thermal effect, and this is the idea headspring of this thesis. In this thesis, magnetic chitosan composite were prepared via two methods, also added magnetic field to control the inorganic fillers in the chitosan matrix.1. Preparation of magnetite/chitosan nanocomposite via in situ compositing methodIn-situ compositing method was used to prepare magnetic chitosan rod by using chitosan membrane as template and NaOH as precipitant. Layer structure of the magnetic chitosan rods was observed from the digital photos, the SEM images showed the micro layer structured of the rods at the same time, the mechanism for preparing the rods was discussed in detail. From the TEM images it can be concluded that the size of Fe₃O₄ particles was about 15nm, and dispersed well in chitosan matrix. X-ray diffraction analysis results demonstrate the formation of magnetite in the chitosan matrix. From the magnetic measurement, it could be concluded that the magnetic chitosan rods were super-paramagnetic. Mechanical properties of the magnetic chitosan rods were measured. From magnetic measurement it can concluded that the as-prepared magnetite is super-paramagnetic.2. Preparation of magnetite/hydroxyapatite/chitosan rods via in-situ precipitation.The magnetite/hydroxyapatite/chitosan rods were prepared by blending magnetic hydroxyapatite with chitosan via in-situ precipitation. Magnetic hydroxyapatite was obtained by co-precipitation method. X-ray Diffraction （XRD）, size distribution and magnetic measurement were performed to characterize the as- prepared magnetic hydroxyapatite. It could be also concluded from the three point bending test that the mechanical properties improved as the inorganic content decreased. The microstructure of magnetic hydroxyapatite/chitosan rods were carried out by scanning electron microscopy （SEM）.3. Preparation and characterization of magnetite/hydroxyapatite/chitosan nano-composite by in-situ compositing methodThe chitosan /hydroxyapatite /Magnetite nano-composites were prepared viain-situ compositing by preparing precursor solutions and models with chitosan membrane; also this method solved the problem of the nano-sized particles aggregation in polymer matrix. These nano-composites were characterized by chemical, spectroscopic, magnetic, mechanical and morphological methods. Comparison of the X-ray diffraction patterns and FT-IR spectra of the nano-composites with those of pure components revealed that the formation of hydroxyapatite and magnetite. Transmission Electron Microscope results showed that the size of as-prepared inorganic particles was under 100 nm, and dispersed homogeneously in the chitosan matrix. Scanning electron microscopy （SEM） was carried out to investigate the microstructure of CS/HA/Fe3O4 composite. From the magnetic measurement, it could be concluded that the nano-composites were super-paramagnetic. Mechanical properties of CS/HA/Fe3O4 composite rod are much better than that prepared via traditional method. 4. The orientation of inorganic fillers in chitosan matrixMagnetite/chitosan nano-composite was prepared via in-situ compositing in the magnetic environment. From the XRD, TEM testing results, it can be concluded that nano magnetite particles arranged orderly in the chitosan matrix. Also, the method of in situ hybridization was explored to prepare CS/HA/magnetite nanocomposite in the magnetic environment, and from the TEM images it can be concluded that the inorganic fillers were oriented.更多还原