【作者】 邓江峰；

【导师】 沈强； 姚礼峰；

【作者基本信息】 武汉理工大学 ， 材料学， 2007， 硕士

【摘要】 核壳结构材料具有不同于核壳单一组分的性质，因而一直是材料领域内的一大研究热点。将核壳材料去核后就得到中空材料，这种中空材料具有特殊的空心结构，表面壳层含有大量的微孔，具有渗透性，在药物可控缓释方面具有巨大的应用潜景。目前以硬模板法制备核壳结构微球采用的多是聚苯乙烯模板，并利用该模板制备出纳米尺度的核壳微球，但对于微米级别核壳微球的制备报道相对较少。本文采用分散聚合法，成功合成出单分散性聚苯乙烯微球，粒径3～5μm，并制备得到磺化聚苯乙烯模板粒子。以磺化聚苯乙烯微球为模板，乙醇为介质，采用水解钛酸丁酯，二次包覆方法制备了PS／TiO₂核壳结构微球。研究了影响核壳结构微球表面形貌以及中空微球结构的因素，结果表明，当磺化聚苯乙烯用量在30mg，钛酸丁酯用量为1.0ml，水用量为0.5ml时，制备的核壳微球有光滑、均匀的包覆表面。当水解包覆反应时间达到2h后，包覆反应基本结束。通过甲苯溶解和高温煅烧的方式去核，制备出中空TiO₂颗粒，从个别破碎微球断口观察，单次包覆厚度为50nm。以膦酸化壳聚糖改性后的一次包覆PS／TiO₂粒子为模板，在乙醇中氨解正硅酸乙酯制备出PS／TiO₂／SiO₂复合包覆微球。当氨水和去离子水浓度较低时，形成的核壳微球为部分包覆，表面包覆层较粗糙。当氨水和去离子水浓度增大后，形成的是包覆完整、均匀、平滑表面的核壳微球。分别以甲苯溶蚀和高温煅烧的方法去核得到TiO₂／SiO₂双包覆层复合中空微球。以膦酸化壳聚糖改性的PS／TiO₂为模板，通过Fe₃O₄纳米粒子自组装吸附和水解钛酸丁酯制备了PS／TiO₂／Fe₃O₄／TiO₂多层包覆微球。甲苯去核后得到了TiO₂／Fe₃O₄／TiO₂复合夹心结构中空粒子。以磺化PS为模板，Fe³⁺、Fe²⁺化学共沉淀法制备的包覆微球，微球表面吸附的是Fe₃O₄和Fe（OH）₃混合包覆产物，且只有部分包覆。以Fe²⁺沉淀法制备的核壳微球，包覆较均匀，表面粗糙。通过磁铁的宏观测试表明，微球都具有良好的磁性能。更多还原

【Abstract】 Core-Shell structure material is an attractive topic in material areas due to its special nature different from the core or shell single component. Hollow materials are formed by removal of the core by a solvent or heating. Hollow microspheres have widely potential applications as delivery vehicles for the controlled release of drugs, dyes due to their special hollow structure. The surface of the shell contains a lot of microporous, was permeability. Polystyrene spheres are more used as a template to prepare core-shell materials nowadays. And nano-scale core-shell spheres produced, but for micron-level core-shell spheres relatively few reports.Monodisperse polystyrene microspheres with 3～5μm diameter were synthesized by dispersion polymerization. As sulfonated polystyrene microspheres template, Titania coated polystyrene core-shell spheres produced through hydrolysis Tetrabutyl titanate in ethanol. The influence of Tetrabutyl titanate, deionized water and reaction time on the formation of the core-shell microspheres and hollow microspheres are studied. It revealed that core-shell spheres were smooth and homogeneous surface on the condition of 30mg template, 1.0ml Tetrabutyl titanate and 0.5 ml deionized water. Coating reaction almost finished in 2 hours. The resulting hollow titanium dioxide was obtained by removal of the core with toluene or by calcination. From the individual broken particles fracture observation, a single coating thickness about 50nm.Using chitosan modified PS/TiO₂ core-shell particles as template, silicon dioxide coating formed onto PS/TiO₂ surface by hydrolysis tetraethyl ortho-silicate in ammonia and composite core-shell spheres prepared. Rough and half coating surface in lower ammonia and deionized water concentration. The integrity, uniform and smooth coating surface produced when ammonia and deionized water concentration increased. Hollow microspheres were made by removing template with toluene and calcination.With the same PS/TiO₂ particles as a template, PS/TiO₂/Fe₃O₄/TiO₂ multilayer coated microspheres produced through Fe₃O₄ nanoparticles adsorption and hydrolysis of Tetrabutyl titanate in ethanol. TiO₂/Fe₃O₄/TiO₂ composite sandwich structure hollow particles obtained when removing cores. Ferrous and ferric as raw materials, magnetic coating spheres prepared by chemical coprecipitation method. It revealed that both Fe₃O₄ and Fe（OH）₃ composite coating formed. The more homogeneous and rough surface core-shell microspheres obtained using ferrous as material by precipitation method. Magnet macro tests showed that these microspheres are good magnetic properties.更多还原