【作者】 刘法家；

【导师】 董文钧；

【作者基本信息】 浙江理工大学 ， 应用化学， 2012， 硕士

【摘要】 水凝胶是一种特殊的分散体系，因聚合物相互交联而形成三维网络结构。这种网络结构能够为纳米颗粒的成核和生长提供所需空间和微环境。水凝胶可通过改变单体组成、交联剂类型和制备条件等对其尺寸大小、内部结构和所包含功能基团的种类等进行控制，在合成具有新奇结构先进功能微纳米材料方面有很大的优越性。本论文主要以聚丙烯酰胺水凝胶为模板，利用电流辅助离子迁移的方法，制备了碳酸钙、二氧化铈、金属硫化物等微纳米材料，通过调节电流大小、丙烯酰胺单体含量、反应物浓度以及加入其他功能基团等实验条件，可以对微纳米材料的尺寸和形貌进行控制。本论文主要研究内容和取得的成果如下：1.聚丙烯酰胺水凝胶模板法制备多孔碳酸钙空心球及其性能的研究以聚丙烯酰胺水凝胶为模板，在恒定的直流电流辅助的作用下，成功制备了多孔的碳酸钙空心微球。首先研究了单体含量对碳酸钙空心球形貌的影响，结果表明丙烯酰胺含量为5%时所制备的碳酸钙微球具有较为均一的形貌和尺寸分布。通过控制电流大小、加入生物小分子和β-环糊精等实验条件，制备得到了不同形貌和尺寸的碳酸钙空心微球，并对其形成机理进行了初步的探讨。本实验制备的以碳酸钙/聚丙烯酰胺水凝胶复合材料为载体的药物传递系统，利用β-环糊精的包合作用将布洛芬成功地负载到复合材料里，其结合了水凝胶在溶液中的溶胀性质和碳酸钙在不同pH下的稳定性。研究表明，该药物传递系统对pH具有良好的响应性。2.聚丙烯酰胺水凝胶模板法制备多壁二氧化铈多孔微球以聚丙烯酰胺水凝胶为模板，在恒定的直流电流辅助的作用下，经过热处理去除有机模板，成功地制备得到了多壁的CeO2中空微球。实验结果表明，CeO2中空微球是由在水凝胶内部形成的Ce(OH)3经煅烧氧化后得到，经过煅烧处理后XRD图显示CeO2中空微球为立方相结构。通过改变丙烯酰胺单体的含量、反应时间以及Ce(NO3)3·6H2O水溶液与NaOH水溶液的溶度比可以制备具有一层、二层及多层壁的多孔CeO2中空微球，并对其形成机理进行了一定的探讨。3.聚丙烯酰胺水凝胶模板法制备金属硫化物微纳米材料利用聚丙烯酰胺水凝胶为模板，分别制备了具有不同形貌的硫化铜和硫化镉微纳米材料。研究表明电流在硫化物形成过程中起到了关键的作用。对于硫化铜，通过控制电流大小得到了硫化铜空心球和硫化铜片状结构，再通过调节丙烯酰胺的量得到了由硫化铜纳米片构成的花状结构；对于硫化镉，在一定范围内通过调节电流大小可以控制形成的硫化镉纳米小球的尺寸。初步研究了硫化物微纳米材料的形成机理。更多还原

【Abstract】 Hydrogels are a unique class of macromolecular networks that may contain a large fractionof aqueous solvent within their structure. Their three dimensional network structure formingfrom crosslinking between polymers can provide the space and microenvironment needed for thenucleation and growth of nanoparticles. Hydrogels can be easily assembled in three dimensionswhile displaying multiple functional domains, and their polymerization chemistry allows theincorporation of polar ligands that mimic the acidic matrix proteins regulating mineral growth.So hydrogels are very useful in synthesis of novel advanced functional materials. In this paper,several micro/nano materials, such as hollow calcium carbonate spheres, multi-wall ceria sheresand metal sulfide, were prepared by polyacrylamide hydrogel template method with acurrent-assist approach to promote the migration of ions. The size and morphology of themicro/nano materials could be controlled by varying the current, the content of acrylamide, theconcentration of reactants or adding functional groups. The main content of this paper and theachievement were as following:1. The synthesis of porous CaCO3hollow spheres by polyacrylamide hydrogel templatemethod and the investigation of their propertiesPorous CaCO3hollow spheres were successfully synthesised by polyacrylamide hydrogeltemplate method with a current-assist approach. Firstly, the influence of the content ofacrylamide to the morphology of CaCO3hollow spheres was investigated. The result indicatedthat uniform CaCO3hollow spheres were obtained when the content of acrylamide was5wt%.In addition, CaCO3hollow spheres with various size and morphology were prepared by varyingthe current, adding small biomolecules and β–cyclodextrin. CaCO3/polyacrylamide hydrogelbased drug delivery system (DDS) was prepared. Due to the clathration effect of β–cyclodextrin,ibuprofen molecules were easily loaded into the DDS. This DDS combined the swelling propertyof hydrogel and the pH-sensitive property of CaCO3which resulted in the pH-sensitive propertyof this DDS. In addition, this paper also accounted for the mechanism of the drug release.2. The synthesis of multi-wall CeO2porous spheres by polyacrylamide hydrogel template methodThe porous CeO2hollow spheres were synthesised successfully by polyacrylamide hydrogeltemplate method with a current-assist approach following a thermal treatment. CeO2hollowspheres were transformed from the oxidation of Ce(OH)3which formed inside hydrogel. Aftercalcination, the XRD pattern confirmed that the yellow powders were cubic phase CeO2. PorousCeO2hollow spheres with different number of layers were obtained by varying the content ofacrylamide, the reacting time and the concentration ratio of Ce(NO3)3·6H2O aqueous solution/NaOH aqueous solution. Besides, the formation mechanism of the porous CeO2hollow sphereswas proposed.3. The synthesis of metal sulfide micro/nano materials by polyacrylamide hydrogel templatemethodCopper sulfide and Cadmium sulphide micro/nano materials were synthesised bypolyacrylamide hydrogel template method. The result showed that the current played animportant role in the forming of the metal sulfide. Copper sulfide hollow nanospheres andnanosheets were obtained by varying the current, and then a flower-like copper sulfide structurewas prepared by varying the content of acrylamide. As to cadmium sulphide, different size ofcadmium sulphide spheres were prepared by varying the current in a certain range. Finally, theformation mechanism of metal sulfide micro/nano materials was discussed.更多还原