【作者】 牛余忠；

【导师】 曲荣君；

【作者基本信息】 鲁东大学 ， 高分子化学与物理， 2007， 硕士

【摘要】 聚酰胺-胺型（Polyamidoamine, PAMAM）树形大分子是近二十年才成功合成的一类新型高分子材料,由于具有精确的分子结构、分子内存在大量的空腔以及表面含有大量的官能团等特点,容易实现对金属及其离子的包埋与吸附,这些特点使其在多个领域有潜在的应用价值,成为相关领域的研究热点。本文采用发散式合成法,通过重复以下两步反应:（1）丙烯酸甲酯与表面氨基的Michael加成反应;（2）乙二胺同以酯基为端基的产物的酰胺化反应,得到了一系列硅胶锚合的PAMAM型类树形大分子,利用傅立叶红外光谱、X-射线衍射、热重分析、孔径分析、扫描电镜等方法对产物进行了表征,分别研究了对Au³⁺、Pd²⁺、Pt⁴⁺、Ag⁺、Cu²⁺、Zn²⁺、Hg²⁺等金属离子的静态吸附容量、动态吸附容量以及酸度、pH值对吸附量的影响。通过实验得到以下结论:1.通过发散式合成法成功合成一系列以酯基和氨基为端基的硅胶锚合的PAMAM型类树形大分子。硅胶表面类树形大分子的接枝率随着类树形大分子代数的增加而增加,但是由于空间位阻的存在以及分子内和分子间交联产物的出现,实际接枝率要低于理论值。2.通过红外光谱跟踪测试反应进程结果显示,在25℃下,至少分别需要5天、7天、8天、9天才能使以酯基为端基的SiO₂-G0.5、SiO₂-G1.5、SiO₂-G2.5、SiO₂-G3.5等半代产品与乙二胺完全反应得到相应的以氨基为端基的SiO₂-G0、SiO₂-G1.0、SiO₂-G2.0、SiO₂-G3.0、SiO₂-G4.0等整代产品。3.产物的BET表面积,BJH脱附平均孔径、孔容随着硅胶表面锚合的树形大分子的代数的增加逐渐降低。4.静态吸附实验结果表明,所有的以酯基和氨基为端基的PAMAM型螯合树脂对贵金属离子Au³⁺和Pd²⁺表现出了优于Pt⁴⁺、Ag⁺及Cu²⁺、Zn²⁺、Hg²⁺等贱金属离子的吸附性能;并且研究结果表明,并不是硅胶表面的接枝率越高对金属离子的饱和吸附量越大。5.动态吸附实验结果表明,除了以酯基为端基的半代产品对Ag⁺的吸附中存在多种吸附机理外,对Au³⁺、Pd²⁺、Pt⁴⁺、Cu²⁺、Hg²⁺的动态吸附都属液膜扩散控制机理。6.溶液酸度及pH值对合成的PAMAM型类树形大分子的吸附性能具有重要的影响。对Pd²⁺的最佳吸附酸度为2mol/L;除了pH值对以氨基为端基的整代产品吸附Cu²⁺影响比较复杂外,大多数产品对Cu²⁺和Ag⁺的最佳吸附pH值为4。更多还原

【Abstract】 Polyamidoamine （PAMAM） is one of the novel dendritic polymers which was successfully synthesized in recently decades. It is an ideal candidate for metal ions adsorption because of its well-defined structure, hollow cavities deep within the branching structure and high density of functional groups. Great attenation had been paid to PAMAM dendrimer due to its great potential appalication in many fields.In this thesis, a series of ester- and amino-terminated dendrimer-like PAMAM grafted silica-gel was prepared with a divergent method by repeating two processes: （1） Michael addition of methyl acrylate （MA） to surface amino groups; （2） amidation of the resulting esters with ethylenediamine （EDA） fromγ-aminopropyl silica gel core. Their structures were characterized by FTIR, XRD, TG, porous analysis and SEM. Au³⁺, Pd²⁺, Pt⁴⁺, Ag⁺, Cu²⁺, Zn²⁺ and Hg²⁺ were chosen as representative to investigate the static and dynamic adsorption properties of the dendrimer-like PAMAM. The relationship between adsorption capacities and acid concentrtation, pH value was also evaluated. Some conclusions can be drawn as follows:1. Ester- and amino-terminated dendrimer-like highly branched PAMAM polymers were successfully grafted on the surface of silica gel via a divergent method. The percentage of grafting of dendrimer-like PAMAM polymer on the surface of silica-gel increased with increase of the number of generations of the grafted PAMAM dendrimer, but the observed grafting at every generation was much smaller than that of the theoretical value because of steric hindrance and inter- and intra-groups crosslinking.2. The monitoring by FTIR indicated it needed at least 5, 7, 8, and 9 days for SiO₂-G0.5, SiO₂-G1.5, SiO₂-G2.5 and SiO₂-G3.5 to be converted into SiO₂-G0, SiO₂-G1.0, SiO₂-G2.0、SiO₂-G3.0 and SiO₂-G4.0, respectively at 25℃.3. The BET surface area, BJH desorption average pore diameter and BJH desorption cumulative volume of pores for the products decrease after the series of grafting reactions.4. Static adsorption showed that both ester- and amino-terminated dendrimer-like PAMAM grafted silica-gel exhibited better adsorption capabilities for Au³⁺ and Pd²⁺ than for base metal ions Cu²⁺, Zn²⁺, Hg²⁺ and noble metal ions Pt⁴⁺ and Ag⁺. Also, one conclusion can be drawn form the investigation, that is, a high percentage of grafting of polymer onto the surface of silica-gel did not mean a high adsorption capacity. 5. Dynamic adsorption shows that the adsorption mechanism for Au³⁺, Pd²⁺, Pt⁴⁺, Cu²⁺, Hg²⁺ are all belongs to the Film Diffusion Control mechanism, except the dynamic adsorption of ester-terminated dendrimer-like PAMAM grafted silica-gel for Ag⁺.6. Acid concentrtation and pH value have an important effect on sorption properties. For Pd²⁺, the optimum acid concentrtation is 2mol/L. As for Ag⁺ and Cu²⁺, most of the products exhibite highest sorption capacities when pH value is 4, except the sorption for Cu²⁺ of the amino-terminated products.更多还原