聚合诱导自组装构建界面富集伯胺基团的反应性纳米材料
发布时间：2018-10-15 16:54
【摘要】：在水溶液中,两亲性嵌段共聚物的自组装,通常会伴随着成核嵌段的疏水活性基团的包裹问题。这一行为势必影响活性基团对水介质中物质的可及性,导致组装体性能的降低,如作为催化剂的催化效率的降低。本论文提出利用水溶液分散聚合驱动聚合反应诱导自组装(Polymerization-induced self-assembly,PISA),以此解决上述问题。水溶液PISA通过如下途径来实现,即通过水溶性单体的RAFT聚合对一个完全水溶的大分子链转移剂进行扩链。反应初始阶段形成的嵌段共聚物保持完全水溶状态。当转化率达到一定程度时,第二嵌段开始发生相态转变,驱动嵌段共聚物的原位自组装。在系统文献调研的基础上,本论文探讨了室温水溶液中通过水溶液分散聚合,快速高效制备具有高反应活性和介质可及性的水溶性嵌段共聚物纳米材料。首先,构建一个基于商品化双丙酮丙烯酰胺(diacetone acrylamide,DAAM)单体水溶液分散RAFT聚合的PISA过程。在室温和可见光照下,以完全亲水的聚N-异羟丙基甲基丙烯酰胺(poly2-hydroxypropylmethacrylamide,PHPMA)为大分子链转移剂,以2,4,6-三甲基苯甲酰基苯基亚膦酸钠(sodium phenyl-2,4,6-trimethylbenzoylphosphinate,SPTP)作为光引发剂,实现了DAAM单体的水溶液分散聚合,进而诱导其自组装。单体在30 min内几乎消耗完全。随着聚合反应的进行,依次经历去水合化、相分离、胶束化、反应加速的PISA过程,最终形成双峰分布的球形胶束。以上结果表明,以PHPMA为大分子链转移剂的DAAM单体可见光活化室温水溶液RAFT聚合反应,是一个快速高效的PISA过程。在此基础上,本论文探讨了制备具有高反应活性和介质可及性的水溶性嵌段共聚物纳米材料的新方法。本论文利用含有NH3+官能团的N-2-氨基乙基丙烯酰胺盐酸盐(N-2-aminoethylacrylamide hydrochloride,AEAM)单体替换少量的DAAM单体,进行上述PISA过程。AEAM结构单元的嵌入,促进了成核嵌段的轻微水合化,从而实现疏水核对两种单体的富集,进而实现AEAM及DAAM单体的聚合反应加速。嵌入的AEAM越多,嵌段共聚物的分子量分布越窄。原位组装与链增长同步进行,促使NH3+单元趋向于富集在核-壳界面,而DAAM单元塌陷形成疏水核。这一PISA过程,具有显著的实时和高选择性自组装特征。以上结果表明,利用少量AEAM和大量DAAM无规共聚的PISA过程,可以构建胶束核-壳界面富集NH3+功能基团的新型反应性嵌段共聚物纳米材料。通过水溶液电泳和核磁共振技术,论证了胶束核壳界面富集的NH3+功能基团具有优异的可及性。在碱性水溶液中,利用胶束核壳界面的伯胺基团与吡啶二醛PDCA(pyridine-2,6-dicarboxaldehyde)的动态亚胺化反应形成亚胺配体,并与Zn(II)进行原位配位反应,构建了功能配位金属中心准确限域在胶束核-壳界面的功能纳米材料。这一原位功能化过程,充分论证了反应性纳米材料的高反应活性。以上结果表明,通过上述PISA过程构建的反应性纳米粒子具有良好的可及性和反应活性。通过上述策略,有效克服了在水溶液中成核嵌段的疏水活性基团的包裹问题。综上所述,本论文实现了商品化DAAM单体水溶液分散聚合驱动聚合反应诱导自组装。通过相对疏水的DAAM单体与亲水AEAM单体的无规共聚合反应,实现了共聚单体的实时和选择性自组装。在室温水溶液中,快速高效制备了具有高反应活性和介质可及性的水溶性嵌段共聚物纳米材料。以上研究为模仿金属酶催化的水溶性催化剂的制备提供了全新的构建平台。
[Abstract]:In aqueous solutions, the self-assembly of amphiphilic block copolymers usually accompanies the wrapping of hydrophobic active groups of the nucleation block. This behavior tends to affect the accessibility of the active groups to the substances in the aqueous medium, leading to a reduction in the performance of the assembly, such as a reduction in the catalytic efficiency as a catalyst. In this paper, using aqueous dispersion polymerization to drive polymerization to induce self-assembly (PISA) to solve the above problems. The aqueous solution PISA is achieved by expanding the chain of a completely water-soluble macromolecular chain transfer agent by the RAFT polymerization of the water-soluble monomer. the block copolymer formed during the initial stage of the reaction remains in a completely water-soluble state. When the conversion reaches a certain degree, the second block begins to undergo phase change, and the in-situ self-assembly of the block copolymer is driven. Based on the research of systematic literature, this paper discusses the rapid and efficient preparation of water-soluble block copolymer nano-materials with high reaction activity and medium availability through dispersion polymerization of aqueous solution in aqueous solution at room temperature. First, a PISA process for dispersing RAFT polymerization on a commercial diacetone (DAAM) monomer aqueous solution was constructed. In the presence of room temperature and visible light, the aqueous dispersion polymerization of DAAM monomers was achieved by using a fully hydrophilic poly (N-hydroxyaryldimethylaniline, PHPMA) as a macromolecular chain transfer agent, and 2, 4, 6-trimethylcyclohexylene-2, 4, 6-trixylylene-2, 4, 6-trixylenol (SPTP) as photoinitiator. so as to induce self-assembly. The monomer was almost completely consumed within 30 minutes. With the progress of the polymerization reaction, the PISA process of dehydration, phase separation, micelle and reaction acceleration is successively subjected to the reaction, and finally the spherical micelle with the bimodal distribution is formed. The above results show that the RAFT polymerization of DAAM monomer with PHPMA as a chain transfer agent is a fast and efficient PISA process. On the basis of this, a new method for preparing water-soluble block copolymer nano-materials with high reaction activity and medium availability is discussed in this paper. The PISA process was carried out by replacing a small amount of DAAM monomer with N-2-aminoethylbenzoic acid hydrochloride (AEAM) monomer containing NH3 + functional group. the embedding of the AEAM structural unit promotes the slight hydration of the nucleation block so as to realize the hydrophobic check of the enrichment of the two monomers, thereby realizing the polymerization reaction acceleration of the AEAM and the DAAM monomers. The more AEAM embedded, the narrower the molecular weight distribution of the block copolymer. In-situ assembly is carried out synchronously with chain growth, so that NH3 + cells tend to be enriched in the core-shell interface, while DAAM units collapse to form hydrophobic cores. This PISA process has significant real-time and high selectivity self-assembly features. The above results show that a novel reactive block copolymer nano-material enriched with NH3 + functional groups can be constructed by using a small amount of AEAM and a large amount of DAAM random copolymerization PISA process. By means of aqueous solution electrophoresis and nuclear magnetic resonance (NMR) technology, it is demonstrated that the rich NH3 + functional groups in the interface of micellar nuclear shell have excellent properties. In alkaline aqueous solution, imine ligand is formed by the dynamic imidization reaction of the primary amine group of the shell interface of the micelle and the dialdehyde PDCA (pyridine-2,6-dicarbaoxaldehyde), and in-situ coordination reaction is carried out with Zn (II), and the functional nano material with the function coordination metal central accurate limit domain in the micelle core-shell interface is constructed. The in-situ functionalization process fully demonstrates the high reactivity of reactive nano-materials. The above results show that the reactive nanoparticles constructed by the above PISA process have good workability and reactivity. Through the strategy, the problem of wrapping the hydrophobic active group of the nucleation block in the aqueous solution is effectively overcome. In summary, this paper realizes the self-assembly of a commercial DAAM monomer aqueous dispersion polymerization-driven polymerization reaction. Real-time and selective self-assembly of comonomers is achieved by random co-polymerization of relatively hydrophobic DAAM monomers with hydrophilic AEAM monomers. in that aqueous solution of room temperature, a water-soluble block copolymer nano material with high reaction activity and medium availability is rapidly and efficiently prepared. The above research provides a brand-new construction platform for the preparation of water-soluble catalysts catalyzed by metalloenzymes.
【学位授予单位】：苏州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1
[Abstract]:In aqueous solutions, the self-assembly of amphiphilic block copolymers usually accompanies the wrapping of hydrophobic active groups of the nucleation block. This behavior tends to affect the accessibility of the active groups to the substances in the aqueous medium, leading to a reduction in the performance of the assembly, such as a reduction in the catalytic efficiency as a catalyst. In this paper, using aqueous dispersion polymerization to drive polymerization to induce self-assembly (PISA) to solve the above problems. The aqueous solution PISA is achieved by expanding the chain of a completely water-soluble macromolecular chain transfer agent by the RAFT polymerization of the water-soluble monomer. the block copolymer formed during the initial stage of the reaction remains in a completely water-soluble state. When the conversion reaches a certain degree, the second block begins to undergo phase change, and the in-situ self-assembly of the block copolymer is driven. Based on the research of systematic literature, this paper discusses the rapid and efficient preparation of water-soluble block copolymer nano-materials with high reaction activity and medium availability through dispersion polymerization of aqueous solution in aqueous solution at room temperature. First, a PISA process for dispersing RAFT polymerization on a commercial diacetone (DAAM) monomer aqueous solution was constructed. In the presence of room temperature and visible light, the aqueous dispersion polymerization of DAAM monomers was achieved by using a fully hydrophilic poly (N-hydroxyaryldimethylaniline, PHPMA) as a macromolecular chain transfer agent, and 2, 4, 6-trimethylcyclohexylene-2, 4, 6-trixylylene-2, 4, 6-trixylenol (SPTP) as photoinitiator. so as to induce self-assembly. The monomer was almost completely consumed within 30 minutes. With the progress of the polymerization reaction, the PISA process of dehydration, phase separation, micelle and reaction acceleration is successively subjected to the reaction, and finally the spherical micelle with the bimodal distribution is formed. The above results show that the RAFT polymerization of DAAM monomer with PHPMA as a chain transfer agent is a fast and efficient PISA process. On the basis of this, a new method for preparing water-soluble block copolymer nano-materials with high reaction activity and medium availability is discussed in this paper. The PISA process was carried out by replacing a small amount of DAAM monomer with N-2-aminoethylbenzoic acid hydrochloride (AEAM) monomer containing NH3 + functional group. the embedding of the AEAM structural unit promotes the slight hydration of the nucleation block so as to realize the hydrophobic check of the enrichment of the two monomers, thereby realizing the polymerization reaction acceleration of the AEAM and the DAAM monomers. The more AEAM embedded, the narrower the molecular weight distribution of the block copolymer. In-situ assembly is carried out synchronously with chain growth, so that NH3 + cells tend to be enriched in the core-shell interface, while DAAM units collapse to form hydrophobic cores. This PISA process has significant real-time and high selectivity self-assembly features. The above results show that a novel reactive block copolymer nano-material enriched with NH3 + functional groups can be constructed by using a small amount of AEAM and a large amount of DAAM random copolymerization PISA process. By means of aqueous solution electrophoresis and nuclear magnetic resonance (NMR) technology, it is demonstrated that the rich NH3 + functional groups in the interface of micellar nuclear shell have excellent properties. In alkaline aqueous solution, imine ligand is formed by the dynamic imidization reaction of the primary amine group of the shell interface of the micelle and the dialdehyde PDCA (pyridine-2,6-dicarbaoxaldehyde), and in-situ coordination reaction is carried out with Zn (II), and the functional nano material with the function coordination metal central accurate limit domain in the micelle core-shell interface is constructed. The in-situ functionalization process fully demonstrates the high reactivity of reactive nano-materials. The above results show that the reactive nanoparticles constructed by the above PISA process have good workability and reactivity. Through the strategy, the problem of wrapping the hydrophobic active group of the nucleation block in the aqueous solution is effectively overcome. In summary, this paper realizes the self-assembly of a commercial DAAM monomer aqueous dispersion polymerization-driven polymerization reaction. Real-time and selective self-assembly of comonomers is achieved by random co-polymerization of relatively hydrophobic DAAM monomers with hydrophilic AEAM monomers. in that aqueous solution of room temperature, a water-soluble block copolymer nano material with high reaction activity and medium availability is rapidly and efficiently prepared. The above research provides a brand-new construction platform for the preparation of water-soluble catalysts catalyzed by metalloenzymes.
【学位授予单位】：苏州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1
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